Ward

iTrader: (1)

My car is finally street legal, so I've been driving it around town all weekend. The interior is stripped down for now, there's no carpet in it. I noticed that the fuel pump seems awfully loud, I can hear it whining. Maybe it's just because the carpet is out, but I don't think it should be audible from inside the car. Is this normal, or is my fuel pump on the way out?

Fast92RS

iTrader: (2)

Its pretty much normal. Especially with no carpet in the car. The sound of the pump just echos inside the tank making it sound pretty loud.

Theking

iTrader: (1)

Without carpet it may sound awful inside the car when the engine isnt working on a higher RPM and sound out the F/P sound..

jester_587

I also have a Whine in my fuel tank from the pump. Its not a constant whine but only does it after i have been on the road for 30 min to an hour, and sooner on hot days. The fuel gauge will rise when the whine starts. There is a pause in the whining, and like I said its not constant but at random will start and stop and randomly whine for 1 sec up to 3 to 5 seconds, the stop again, all after driving for a bit. Original pump burned out and the new one is 3 months old and is a Bosch pump. Never had the problem until I put in a new pump. No lines are pinched and it was properly installed, and the fuel filter is not clogged. So I am leaning on Charcoal canister is plugged or perhaps the fuel pressure regulator, or the vent on the bottom of the tank is also clogged. Please help this car is in great shape and runs very nice until i have this problem. If I dont pull over and stop the car and vent the tank the car will stall. Starts right up and then drives until the pump whines again then will stall.

thegooseman

My problem is very similar, with the exception of the stalling.

jester_587

I have been to a few car shows and asked about my problem. 2 people told me to look how close my fuel lines are to my headders. With headders installed my pressure and return lines come about 5 inches from my headders. If looked at at night and after driving a while the headders glow hot, with fuel lines so close they sugjested VAPOR LOCK. That the fuel was boiling inside one of those lines and to take some heat tape or headder wrapp and wrapp the headders in that area to stop the transfer of heat. They also sugjested to build a little aluminum heat shield around those fuel lines to catch the heat. They said either or should work but both would be best. I havent tried this yet but as soon as I get a chance I will. I hope this helps anybody you gooseman. Again I havent tried it yet but its the best solution that I have heard yet.
Dave
----------
I just posted a possible solution have a look.

firebird

Jester,

I have the same exact problem, but I don't have headers. When the temp is warm outside my fuel pump acts up (whining), and will eventually stall. If it's cold outside I have no problem. Something is heating my fuel up, and I don't know what it is. What did you finally figure out?


jeff

jester_587

firebird, check the fuel lines that go towards the front of the engine. The pressure and return lines run right buy your exhaust on the drivers side. This problem is killing me, I havent messed with it yet, but I dunno what else to do, I have put 5 fuel pumps in the car now and still have the same problem, so its safe to say its not the fuel pump. Good thing its under warenty. Now another thought I had was the muffler... If its too close to the gas tank then perhaps its causing too much heat that way???? I havent checked to see if mine has the heatshield that it should between them but its next on my list. If you figure it out let me know as well and Ill keep you uptodate on my progress.

firebird

I dropped my muffler away from the heat shield as for as I could, but that didn't help. I'm goint to check the charcoal cannister, and some valve near the cannister and some mushroom looking valve near the shock abosrber on the left rear... If you find away around this problem me know, and I'll do the same.....;

jester_587

My charcoal canister is good and so is the little valve near it, the valve at the tank that you are referring too only lets are IN and is very hard to push air out that way, so they are not the problem either. Hope I saved you some time.

jgrist63

I'm also having a whining problem with my newer fuel pump. Where is the charcoal canister located and how do I check it? Also, when the pump starts to whine, I can smell gasoline vapor outside the car.

Thanks

jester_587

The charcoal canister is located on the drivers side front right behind the headlights. It is a cylinder shaped contraption that has either one or many hoses attached to it on the top and may also have an electrical connector. The Canisters vary from camaro to camaro and firebird to firebird. The fuel smell is very normal for this problem. The question is what is your particulars to this problem. You need to check the hoses and make sure that they are all attached and in working order. Then depending on the specs of your car, if you have headers (modified exhaust) or exhaust manifolds (stock exhaust) There are 2 fuel lines a pressure and return line that run along the drivers side and up near the front of the headers. This is the suspected problem for most of us. The headers create alot of heat and it is suspected that the fuel in the lines that run near it is heating up to a boiling point and causing this crappy problem. So the solution for that is to either fabricate a heat shield for those 2 fuel lines near the exhaust or to get some header wrap or header tape and wrapp the headers on that side to contain the heat. That will not hinder performance in any way and even looks cool if done right. Infact is supposed to help performance with the wrapp according to the package. I did not notice any performance differance, but understand where they are drawing their conclusion from. The other idea is your muffler is too close to your Gas tank. There should be a heat shield inbetween the 2 but if its missing or not doing its job then will heat up the gas in your tank and cause the same problem. Another sugestion was that your fuel pressure regulator is bad, and to replace it to fix the problem. My information is from a Group of 3rd gen Camaro and Firebird owners that I belong too. They have informed me that this is a common problem and this was their sugestion on a fix for it. I am happy to help in anyway, just keep emailing me and ill respond within a day. P.S. I have put 5 fuel pumps in the car so thats not the problem. Our cars all are a bit different so let me know what car you have and ill try to steer you in the right direction. I have a 1986 Camaro IROC-Z28 that has been baby'd all its life and has only 64k miles on it. I found it parked in some old ladys garage, she said she only drove it 1 or 2 times a month just to keep it running, she apparently did not like the car and had no idea of the problem, due to it only showing its ugly head on warmer days.

Slowridr

iTrader: (1)

Jester Ive been chasing this for about 1 mth now. Before I wrap the manifold I want to check the canister everyone has been talking about. My car has done the same whining from the fuel pump. Is there anything mechanical involved with the canister to break down and prevent it from doing its job. If so what is it and how can I check it. The fuel tank sheild is self explainatory. I have stock manifolds and I have not looked at them regarding wraping them yet. Has anyone ever wraped manifolds with this tape? If so can they chime in and let me know how difficult a process this is.

My car had gotten real bad with the sputtering and cutting off. But for some reason Ive been able to drive it recently with only intermittent sputtering.

Slowridr

iTrader: (1)

Also I forgot to mention whenever it begins to sputter and loose power if I put car in nuetral and shut it off and crank it back up it runs just fine. If it is boiling gas how does the turnoff/crankup make it go away?

Also I must say turnoff/crankup makes it go away for a while then it will come back.

jester_587

The canister has no mechanical anything involved with it just some hoses and perhaps an electrical connector. The canister is filled with Charcoal that obsorbes the fuel vapors from the fuel tank itself, the vapors are stored and used when the car needs it. If there is a pool of fuel under the canister then its bad. You can check by simply popping the hood and looking at it. If there is no fuel there then its a good bet that the canister is not the problem and its most likely the fuel pressure regulator or excessive heat from your exhaust. The exhaust tape is not sticky in any way and I dont know why they call it tape but it must be securred by metal ties. I wrapped my headders while they were still on the car and it was a pain and took forever. So its advisable to take them off the car to do it. Wrapping the manifolds should be even easier than headers. Once the car is shut off the pressure may be relieved enough to start the car back up, is my theory but after the fuel heats back up after a little bit of cooling then the problem would return. Then again the fuel pressure regulator is the other option for the problem. Im not sure how they work so I dont know what to do about it, but it was sudjested to me that this is the cause for the problem as well as the other ideas that I mentioned. I have asked around at repair shops and nobody has any answers so it looks like were on our own.

thirdgen88

I have had periodic fuel pump whine, only in spring/summer when its warm or hot outside. Today (first nice weekend) I had the problem again.. It happens when I've been driving slow speeds for extended periods (around town). I noticed that there was a LOT of pressure in the tank. Here is what I know about the fuel system:

The little white valve above the rear axle coming from the fuel tank is a one way check valve, designed to allow air to enter the tank (to keep the tank from sucking in when fuel is used out of it). Then you have two fuel lines (send and return). The last line is one that goes up front, first into the little black valve, then on to the canister.

I had replaced the little valve before winter, trying to fix this problem. I tested the old valve, and it did not open at the design pressure (around 2 psi) correctly. I thought for sure I had it licked until today. The excessive pressure I noticed from the fuel tank (almost enough to keep me from putting the gas cap back on!!) had to mean it still wasn't venting properly.

Turns out, that little line (maybe 1/4") that goes all the way up front was definately clogged (rust? carbon?). Using my air compressor, I blew the line clear (disconnecting it first in the back). I've got a Carter High performance in-tank pump in it right now, and where it starts whining is where my old Holley pump would cut out and lose pressure. I'm hoping this is the true solution to this issue. I'll try to update if the whine/excessive pressure comes back. A note to everybody to make sure that vapor line is actually clear so the rest of the system can do its job!!

Slowridr

iTrader: (1)

Ok some good stuff to digest here. Where is the fuel pressure regulator. I hope you are going to say that "youre in luck, its not in the fuel tank with the fuel pump"!!!

Mine will only do it when the car has run a while. Drove the car 30-40 miles, all easy cruising before it started to act up.

Here is my thing though, if I get on it even when its cold, it will sputter, it seems like load affects mine as well. I dont need any load to make it sputter/cut off when it gets hot though.

randy111

iTrader: (1)

Ok guys, Put me down on this one as well. I have a newly purchased 89 Firebird V6 2.8 This is my 4th 3rd gen i also own a 91 camaro Convertible with the 305 in it. I have a pretty good understanding of these cars and there little issues they like to have. This one has me and my local club members Stumped! As described above, When the car is cold, or has been sitting for long peorid of time, it starts right up. drives fine for aobut 1/2 hour or so then suddonly i lose pwer. I have all of my interor in this car. The one thing i like about this is that Its almost 100% stock. every air dam, every factory heat shield is in place, every trim peace in the interor is there. Only 2 modifications ever done. Aftermarket stearo was installed with i'm swaping back to stock, AND the previous owner, (The only owner he bought the car new in 89) Put a trap door in the rear trunk area under the carpet. The orginal fuel pump went out or was doing what these are doing, so he replaced it this way. Since i have had it the thing rund and drives great for about 1/2 an hour then i can hear this thing get super loud. starts to wine like crazy i can hear it wine up and down and the motor follows it.. as it wines up, the motor runs ok, as it wines down the motor starts to sputter and miss. then it cuts out after about a minute or two of this and then 3 seconds later the motor dies. I have a stack of aobut 30 recipts from the privous owner of parts that were replaced, water pump, alt, powersteering, so on so on, car has 110k miles on it. The fule pump recipt was there, i took it in exhanged it. On my way home from installing it at a club members house.. Same thing on the new pump. When the previous owner intalled new pump, he as well put in a new fuel filter, as it was listed on the recipt adn i could visuly tell it was new. The pump he put in was only in the car a month before i had it. I went ahed and replace the filter when i did the pump, as well as replacing the fuel pump relay, and i checked the oil pressure swtich, this too is working correctly. The wires on the pump inside and out of the tank seem to be in good condtion and get good signal. Yet i cant seem to get my pump to run for more than 1/2 an hour. IF i keep driving it after it dise, i can go another 10 or 15 minutes, then it dies again, IF i do this repeatedly, it will not start after the 3 or 4th time for about 20 mintues. i got stranded on the side of the highway trying to limp home. This really sucks. it appears i'm having the exact same issue you guys are having. Has anyoen found the "This is the problem fix it liek this" answer yet lol.


-Randy-

Slowridr

iTrader: (1)

Hopefully some more folks will see this and chime in. I have a 4.5 mi commute to work. I usually make it to/from work w/out problems but sometimes I do have to do a shutoff/crankup to stop the sputtering.

randy111

iTrader: (1)

Thats pretty much where i'm at on this one. This thing drives so nice. and is spotless interior. Compleatly bone stock Excelnt condtion except for this crazy fuel pump. I can get to work, and home one way with out any issues. If I end up in traffic or try to drive for longer on the highway, I have to normly stop and shut down for a few. This is gonna be my daily driver once i get the fuel pump issue worked out. Once this is fixed it will be a great car. I just had my brother who dose HVAC work evucate, and refill my a/c system. It freaking throws snowball out the dash now!!!! lol just cant drive very far from home yet.

randy111

iTrader: (1)

::: UPDATE :::

Just wanted to post a update on my fuel pump issue. Few things i foudn out about my car. FIst thing is that previous owner let the car sit for about 3 1/2 years with almost no fuel in the tank. The tank is Coverd in rust inside. I'm most likely going to invest in a new tank some time soon.

After checking the wireing going to the pump, Its getting constat power supply. I checked the Sensor on th oil pump, thats working correctly and sending signal to the pump. I replce the fuel pump relay, and tested it, that too is working correctly. after checking all the eletrical conections, fuses and all other eletrical related components i could think of we moved on to the pressure side of things.

I put a fuel presure guage on the line and found out I was getting 70Psi at the motor. So next step we checked the fuel return lines. I disconected the return line under the hood. put it in a small fuel can to catch the fuel as it came out. started the car, fuel pressure was 35 psi as it sould be. This Automaticly let me know i had a clog some were in the return line. I then checked the line going into the tank. As i have a trap door in my turnk this was easey to check. i disconected the return line going into the tank, turn the key to the "on" postion to start the prime and fuel ran out as it should. (recomendation here, Run your own line from the return line going Out of the turnk as to avoid the houge mess i now have in my turnk, and put it in a fuel can or something to catch the fuel as it comes out) ther was NO clog between the retun line coming off the regulator going to the tank. When the motor was running with the return line disconected from the tank I had 35 psi, when it was connected to the tnak i had 70-77 psi. This led me to the obvious conclusion i had a clog Insid the tank.

So finly we removed the fuel pump assembly out of the tank that holds the pump and sock. I discoverd the metal line running down the side that the float is attached too was clogged at the bottom where the sock is. It was what looked like disolved rust and tar or something. at any rate i had to take a drill bit and by hand (not in a drill) just holding the bit in my hand i cleand out the return tube. about 3 inches of the line was cloged with this tar stuff. It was strong enough to hold back the 70+ psi the fuel pump was sending it so it was pretty good and stuck!

After clearing out the return tube on the pump assembly we put everyting back togather, started up the car no leaks everying works fine. Fuel presure is a stedy 35 psi. I drove it around for about 2 hours after and NO issues what so ever from the pump. Previous to this i could only drive the car for 20-30 min MAX and it would cut out. so tonight i drove around adn it did not give me any issues at all. Over the next few days we will see if this did in fact fix it but as of now it seems to have solved my issue. Hope this helps some of you guys.


-Randy-

Ward

iTrader: (1)

I've been driving my car since last June when I originally posted this, with no problems thus far. The fuel pump is still loud, although I've discovered that it's only loud when the fuel is getting low, like 1/2 tank or less. I have checked fuel pressure at the rail, and it's right where it should be, so I'm sure my lines are fine. My car also now has new carpet, and peel-n-seal under that, so the interior noise isn't as bad as it was. It's still audible though, especially with the windows down stopped at a light. I'm just in the habit now of putting more gas in it whenever the fuel pump starts getting loud. I try to keep at least a half tank in it anyway, to work around the stalling/stumbling on hard right turns problem that early TPI cars have.

loopingz

iTrader: (2)

I think I will have to look at my pressures...

ha-y-n-camaro

Thanks for the update. This seems to be a common problem with camaros. The question for me is if it's worth doing all this work, or just letting it be. If it is affecting how the engine runs, then it's a no brainer. I've heard of people changing the gas cap to a vented one so I tried it. About a half hour of no whining, the engine suddenly went into choke mode and almost quit running. I immediately changed the cap back to the one I had got with the car(which looks like a cheap after market non vented one). It took a couple minutes, but the engine finally came around. I decided to live with the noise. Now the other day I had been driving for a couple hours, stop and go, and suddenly it started to sputter. I thought I was going to have to pull over on the side, but I was able to open it up a bit and get it to run good again. I'm hoping it's not the return of the problem, but I'm not sure what to do now. Has anyone dealt with a similar problem? I'm able to live with the whining, but if the car is going to sputter out, I'm going to have to get down to the bottom of the problem.

randy111

iTrader: (1)

Since i last posted, I had been worried that after running that pump so many times and it shutting off i might have dmanged or shortend the life if the pump, I decided to go ahead and remve it, warranty it and install a fresh pump. I had no issues with the previous one since i cleand out the return line, I just figured one weekend when i had time and the motivation to do it, it would better to get it done then rather than when the pump decided to die some were else and i would be unable to do anyting about it lol. I was just worried the life span of the pump might have been shortend from that pump overworking its self and shuttin off so many times. as of yet i have had No more issues with this. The pump has a "whine" to it more so when the tank gets down around 1/3 or less. Its not so noticable when the tank is full. Its defnitly NOT as loud as previously was and the car runs prefect now. This has fixed all the issues I was having.


-Randy-

91 Ragtop

This problem reared it's ugly head on my 91 today also. Lots of interesting ideas, but here is the breakdown I have:

My 91 is 100% stock.

The problem came up last year for me over the summer time. When it was hot, I'd hear the loud whine from the back of the car. It wouldn't keep running driving down the interstate and I pulled over. After about 45 minutes, it started up again. I ASSumed it was just heat so I was surprised when it came up today.

I drove over 100 miles today and then got to a town that had an unexpected parade of some kind. I got stuck in a lot of traffic. It was probably not more than 70* out. ( This is June, right ) It started the sputter and loud whine. I stopped about 3 different times and let it sit for about 10 minutes, then finally stopped for about 30 minutes. After this, the traffic cleared up and I drove the 145 miles home without any problems.

Last year I drove around with a fuel pressure guage on the car for a few weeks and it consistantly ran at 40 PSI without any problems.

Would this fall under the clogged return theory, or would I have other issues? I really don't want to spend the $$$$ on a fuel pump, although it coudl be the original for all I know. I did the tank recall about 3 years ago, but I ASSume they wouldn't have changed the fuel pump at the same time.

Thanks for any further suggestions!!

Steve

firebird

Here's what I did, and the problem went away. I never tighten the gas cap. Basically, I began to notice that a lot of pressure was building up inside that tank, and possibility be causing the problem. Everytime my car would quiet I'd remove the gas cap, and all kind of pressure would be released. So, I decided to not tighten the gas cap, and I've had no other issues. I been stuck in traffic in hot tempertures, and she continues to run fine without the whine. However, I have noticed that if you let the gas get down to 1/4 of a tank, she'll begin the whine. Hope this helps... Jeff

loopingz

iTrader: (2)

I am loosing fuel in fast turn with the cap on. What would it be with the cap off?

firebird

Loopinz,

I'm not loosing fuel... Sounds like you may have defective cap. Understand that I don't the cap isn't off, I just don't tighten it as much, and it works fine with loosing fuel.

IROCVegas

OK fellas... new to the board etc. but I do appreciate everyone's insight and input here. My BRAND NEW fuel pump whined hard and my BRAND NEW fuel pressure regulator diaphram tore within 2 weeks and flooded my intake with fuel (again). I replaced those because I didn't understand and had no experience with chevrolets. This IROC is the first chevy I have ever owned. I'm a Ford man, but I'm experimenting a little here so ok whatever.

When I first got the car it was shooting fuel out of the exhaust. I put in new bosch injectors thinking the old ones were stuck open... did the pressure test and ta-da... fuel shooting out of the regulator vac line. Replaced regulator diaprham, car ran rich so I figured it was the existing pump because it whined really bad.

Replaced the pump, still whined... round and round... injectors leaked near rail... on and on. Until I read about the fuel line return problem. Pulled the return line... clear as a bell. Pulled the new diaprham after I noticed it was flooding again through the vac line, and decided to test for fuel flow up from the bottom hole under the diaphram (which I thought was the correct path). Well, that was the RETURN PATH. And it was clogged with about an inch of chalky/concretey crap that shut down the return path completely. I wound up pulling the fuel rails and lines and used a piece of wire to clean out the crud (took a long time--it was bad) and put it all back together (including new diaphram). Guess what? No more whine at all.

Finally got a chance to take it on a road test. It died in the Las Vegas heat after about 15 miles of driving on the hot asphalt. Hmmm... back to square one?

I pulled the fuel cap and sure enough, a lot of pressure behind it. Left it loose, still didn't fix the problem of the theoretical vapor lock or whatever. So hmmm....

I eventually pulled the cap off of the fuel pump relay and noticed there was a lot of carbon tracking on the contactor (looks like a set of points). In theory, you will still get the correct voltage because there is minimal contact being made, but you won't have the surface area to correctly power the fuel pump under full load conditions. I swapped relays with another 5-pin to get me home, and the pump surged/whined and died again. The other relay had a resistor between the #12 wire and one of the control wires. Long story short, I pulled into the parts store (won't mention the name) and got a new relay (which did NOT have a resistor) and plugged it in and re-swapped the old wire.

I put the filler cap on the tank to 3 clicks and drove it around quite a bit. Guess what? The pump became slightly audible with a little whine during the heat of the day, but it did not die out. Problem (hopefully) fixed.

The reason I typed all of that story was to say this...

1. clean the return line completely from the tank through the little 2" square aluminum block under the pressure regulator.
2. put in a new fuel pump relay, and make sure it does not have any resistors in it.
3. notice the lack of whine, and lack of dying out when the car gets hot.

Good luck everybody, and thanks to all you guys who have been through this already. I appreciate your help.

loopingz

iTrader: (2)

Thanks for the feedback, I really need to check my return line!

MTXaudioSYSTM

ive had the similar issue you guys have had. ill try a few things tomorrow but for the most part this thread gave me a few ideas. thanks guys

IROCVegas

something else weird happened yesterday... I pulled in after the test drive and actually heard the gas boiling in the tank. Looks like a regular rocket scientist designed the muffler location right below the tank. Yes, the heat shield is in place. Car didn't die though.

MTXaudioSYSTM

ive had the same problem!

but with this fuel pump being in there the longest ive had out of the 6 ive tried its getting very loud...

IROCVegas

Took the car for another trip today... not as hot as usual... drove the interstate no probs... got off the 215 and died on the way home. pump surged (again) and the car leaned out on me and left me sitting in a parking lot looking like an idiot.

Not overly impressed with the chevy offering at this point. Is there a set-up to relocate the muffler out from under the tank with it still being emissions legal or what? chev engineers=idiots.

Chevy Power! YEAH! WHAAAAWH!

I'm definitely against here.

hedberg667

my fuel pump will whine usually when im low on gas. I drive with the needle on E for a while. Since the gauge moves under braking and acceleration i figure im cool. but to you problem with the muffler, I took mine off and have had none of your problems. You would think it would get hotter with the gas escaping right under the tank but then again it could be cooler since the gas isent passing through so much pipe.

IROCVegas

ok finaly fixed it (for now). I looked again at the fuel line routing... I thought the fuel line was a power steering line or something because of how it was ran.

The fuel line comes up at the front of the block on the driver's side and attaches right next to the exhaust manifold and follows the manifold a few inches, with about a 1 inch gap between the line and that hot manifold.

I took a few pieces of alumnum foil and folded them in halves until I had about 16 layers of foil, then wrapped a few of these pieces along and around the fuel lines where they run along the exhaust manifold.

I ran the car yesterday in 116 degree heat and let it set there and idle in the sun until my temp gauge read just below orange (which is where it would have normally died). It didn't whine and it didn't die. It also started back up after I shut it down. Hopefully this is the fix.

If it runs fine for a few weeks I'm going to get some decent adhesive wrap insulation and put it on there.

aurum_duck

iTrader: (2)

this didnt happen on my 92 tbi, but I did replace the pump with a walbro--and it was noticeable, but never changed tone and never sputtered. however, I picked up a 91 with the TPI L98 that had been sitting in a driveway for six years unmaintained, and before cranking it ever, we replaced the tank, sending assembly/pump (almost $1000) with autozone parts. I havent driven the car much because I have this exact problem...it'll run great for 30 minutes, and then the LOUD whining starts, it will change tones, I have a lot, I mean a LOT of pressure in the tank behind the cap (I can see the volatiles escaping from the fuel door), and it's hot hot vapor... initially, it would stall as I let the pressure out, and now it runs fine with the pressure in it or released. What bothers me, is the question of "is it getting hot because the pump is that hot from lack of circulation" or is it getting hot b/c it's circulating through the motor so continuously. I'm off to explore the fuel pressure regulator and fuel return line. the dealership said that the return line was good and that fuel pressure was within limits. just pisses me off that I have to keep messing with this fuel delivery issue. I'm about to take the plenum off, replace the injectors, regulator, and blow through the return line just to be freakin' thorough. Im so ill with this problem that I almost want to wrap it around a tree and start driving a jeep. hahahah I have a screaming fuel pump!

BOSS 357

iTrader: (1)

These issues sound somewhat similar to a nasty problem I d-cked around with for months before a fella on TGO pointed this all out to me. At the time, my problems were a)pressure in the tank b)stalling when I needed to GO c) at a later time, the whirring of the fuel pump.

First, I had mad pressure in my tank that would WOOSH out when I took the cap off. It was so bad that I could hear the tank expand and contract. Not only that, but I could hear the valve wheeze when the tank pressurized. Scary. I know folks say that the little white valve by the tank only inhales, but I replaced it and my venting issue was gone. Note that I temporarily fixed it with a venting gas cap, however I was told this was only a band-aid, if the canister wasn't leaking, then my problem was most likely the vent valve.

The stalling and whirring were "solved" in one fix. Used to be, when I'd mash the gas or sit and let the car get hot for any length of time, it would stall when I wanted to go, much like I had forgotten how to drive my clutch. Also scary when I wanted to duck out of a long stop light that it would pitch and heave as it tried to get going. The solution here was that the pulsator had gone bad. This is a little brake-master-cylinder- looking piece on the fuel sending unit inside the tank, between the pump itself and the outgoing fuel (steel) line inside the tank. I replaced the stock pump with a Walbro 65 gph unit and removed the pulsator altogether. I replaced the pulsator with a piece of fuel-safe rubber hose that came with the new pump (As an added measure, I replaced the entire sending unit, however you can reuse yours, I didn't ever want to delve into this part of my car again) I was told I can buy another one (pulsator) and hope it doesn't go bad in my lifetime or remove it, which I did. The only down side was that I could now hear the pump whining away at all speeds, and obviously, more when the tank was low on fuel. This really isn't an issue for me as my exhaust dumps before the axle and I run chambered exhausts and no mufflers. (think your Harley is loud?)

The parts weren't too expensive, but it did take me a week to fix it (my first time dropping the tank). I can't tell you the relief I had when it came time to pull out in traffic, and my baby screamed up the road laughing at me the whole time for the puzzle it had created for me.

Good luck, don't pull your hair out yet.
Eric

jester_587

Eric, I replaced that valve by the tank on the left side and have continued to have the pressure problem. Its supposed to be a one way valve but when my tank gets so much pressure in it, that valve gets over whelmed and vents OUT through there. I tried the vented gas cap and it seemed to make my problems worse and the tank would dump fuel out of the filler neck, all over the left rear of the car due to the pressure. Charcoal canister looks fine. Fuel pressure is fine untill the problem starts. Any other Ideas. I do have an eddlebrock exhaust sys on the car and the headers on the left side are pretty close to the fuel lines. I guessing at vapor lock from the heat?? Or a fault fuel pressure regulator. I just dont know what else to do. Perhaps that valve a the back I bought was faulty too!?!?

BOSS 357

iTrader: (1)

I have the Edelbrock headers too and they haven't caused me any problems. I though vapor lock was a carb issue of yonder years ago. I doubt we'd have that problem with our cars as the fuel is under more pressure than carburated fuel/lines.

I did have (and still do) have a few instances where fuel spills out from my filler neck. That is caused from the bolt holding the tank strap in place works it's way loose and lets the neck ride on the lip in the plastic piece inside the fuel fill door, and I must tighten it back up to fix the problem. When this happens, the cap clicks too soon and won't seal, hence the fuel coming out (imagine my terror when I saw silver paint from my filler neck on my shiney black paint...). I wonder if your cap isn't sealing properly and consequently may be affecting your fuel system. Proper cap seal is around 2-3 turns and then the clicks should start. If they start immediately, then there's part of your issue.

As I've read thru this post, my only other guess would be clogged fuel lines, faulty FPR (I run an adjustable one), or something amiss with the sending unit or pump itself. There's only X many things it could be: send unit/pump, vent valve, lines, FPR, maybe clogged rail.

This post is rather long so forgive me for asking if you haven't already mentioned, but (other than vent valve and vented cap) what have you fixed and/or replaced already? Can you get a pressure reading when the problem occurs? Is the vac line for the FPR hooked up properly and not damaged? Is this an original sending unit/fuel pump? When did you last replace the filter?

jester_587

I have had 5, yes FIVE fuel pumps put in the car in 2 years. I tried OEM and Bosch pumps and both eventually failed because of the same problem. I had CHEVY put 1 in, and a few different shops put in the other pumps. So its not the pump or crappy mechanic. I do 95% of the maintenance on my vehicles, and only let somebody else work on if the car needs some sort of work that I cant do in my garage. Dropping the tank is a pain so I let somebody else do it. I am a Helicopter Mechanic and can understand and fix any problem that may come, ACCEPT for this damn pressure issue. Im stumped. The pressure and return fuel lines run about 5 inches from my headers on the drivers side and I checked to see if they were clogged and they are not. I disconnected the lines at both ends and blew air in both sides to make sure... The fuel lines up front do get hot being that close to the header, but there isnt much I can do about it. I have tried several caps and still get the same resulting pressure and fuel spillage. I have got good compression and good fuel pressure, I keep the car in good shape and well maintained. Now if I can only fix this problem Ill be happy. I checked all the vacume lines and they are all where they should be and in good condition. I even checked out the factory manual for the exact car I have and was unable to Identify the problem accept for MABEY the FPR, Charcoal Cansiter, or Fuel pump. The only thing I have not touched is the FPR. The fuel filter has been replaced with every pump change. I even had the tank cleaned out while it was out of the car. Injectors are good, no faulty wiring. The Sending unit im not sure if it was replaced with the pump, Ill have to do some digging for that. Once the intermittent whining of the fuel pump starts, I can stop the car, shut it off, open the cap and let it vent for a few minutes, then cap goes back on, start the car, and im good for about another 5 minutes or so untill the whining starts again. If I let he whining go too long the car will stall out. It is strange that if the whining starts before I get on a highway, it will stop as I am driving on the highway at speeds of about 70-80, but If I have to slow down and use my brakes the whining will start immediatly. I dont know if using brakes and having the fuel slosh to the front of the tank does something or... I dont know. Im at a loss. If the weather is cold the pump will work just fine all day.

BOSS 357

iTrader: (1)

First off, let me say emphatically, it's not your fuel pump. Five FPs are enough. You may be killing your fuel pumps with the problem, but they aren't it.

My most simplistic response would be to replace the few parts you haven't done yet. It sounds like there could be a clog which maybe backing up (for lack of a better word) or overworking and overheating your pump. Since you've replaced and checked most everything else, I suggest either getting one from the salvage yard or ordering a new OEM or adjustable (my choice) FPR. Another thing you can do while you've got the plenum off, would be to go ahead and remove the runners and check the fuel rail itself for any clogs. I suggest removing it and the injectors and doing a complete visual, perhaps even running fluid through it to also verify, and blowing it out too.

I think the vapor lock issue may not be applicable to your situation. If the fuel gets too hot and vaporizes, the liquid fuel can still flow, thus not causing a spike in pressure and tank overflow. Again, the high pressure of fuel injection vs low pressure carburation may render vapor lock a non-issue (assuming my logic is correct, someone please correct me). My lines run the same way as yours do with the same Edelbrock headers, so I doubt that is your problem.

Let's run through the logic here: fuel pump replaced, lines clear, new fuel filter, injectors ok, vac lines hooked and clear, tank check valve replced, cap on tight (right?). That leaves FPR, rail, and sending unit. I'd leave the SU as the last thing I did.

LS7Roc

Got the same problem with my 88. Fuel pump whining after driving around (hot engine). If I release the pressure in the tank, it goes away. I smell fuel all around the car when this happens. Tank pressure check valve maybe? Anyone fix this problem yet!

jester_587

I have tried replacing or inspecting everything accept the fuel pressure regulator which is on order and I should receive it in a few days. The problem is in the engine compartment not the fuel tank, but it causes the pump in the tank to fail or act up. I will post results after I get my new adjustable fuel pressure regulator installed and take it on the road for a LONG drive to make sure that it is fixed. I have looked at the valve that is behind the left rear tire near the tank, and I replaced it but that valve lets air into the tank not out so this is not the problem, and did not fix it when I replaced it for the same reason your thinking of. Fuel pressure regulator is a little complicated to change out for the non mechanically minded, but if you are mechanically inclined then should be no problem.

Slowridr

iTrader: (1)

Did all this stuff you all are talking bout. Didnt read all the post here but Ill tell you what fixed mine.

Pulled the fuel tank. It had crud in the bottom. Put it back in after having it boiled at a radiator shop and bam!!!!!!

Have not had a problem since.

chevy lovin

same problem. no solution. whine whine whine stall at 80 mph. acts like its out of gas. after 10 minutes restarts. head to the gas station fill it up. problem stops till the gas goes down a couple of gallons. got to keep it full. its a pain in the a$$. this car is bone stock 87 tpi.

jester_587

Solution!!! Replace Fuel Tank and change fuel filter after tank is replaced. No more problems. The fuel tank will have gunk at the bottom and it gets pulled up in to the pump and eventually clogs the filter and pump. Cleaning the tank is not enough because I already tried that. You have to replace it. They are not that expensive actually, and fairly easy to do.

RPOL98

this has gotta be the first time i've ever heard that replacing the 3rd gen fuel tank is "fairly easy", what with it being ABOVE the axle, etc.

when i did my in-tank fuel pump, it was anything but easy, a 3-day job. what's the secret?

jester_587

The secret is pulling up the carpet in the back, and cutting a hole in the floor. Turn the piece you just cut out into an access panel and thats it. Weather proof it, and pull the carpet back over to cover it. You'll never see it, and if it fails again you have your little access door. Its easy man.