bungo78

iTrader: (1)

1988 Trans Am 5.7

Yesterday I experience fuel pump difficulties. Here's the scenario

For over an hour I drove in 90+ heat. Starting out on the freeway then on to the mountains. Wanted to enjoy the twisties, hills and descends from the hills. I drive an automatic yet I enjoy shifting my own gears.

For a large portion of the mountains while going up, my temp was around 210-220 not going higher than 220.

Now the fun part!

As I was driving, the car lost throttle response and began decelerating until I came to a sluggish stop. When I attempted to start, it tried to turn over yet it would start. I noticed there was a noise in the rear. The sound of pressure whining to escape.

After 15 minutes the car turned over and I began to head back to a ranger station to get a tow. After 2 stops due to the reasons stated previously. I finally made it to the station and received my tow home.

I did a search and found the link below.

https://www.thirdgen.org/forums/tpi/...iling-wtf.html

The individual has similar issues like I experienced. Yet a clear cut solution was not answered.

After yesterday, I decided tonight to drive the car. The temp outside was 78 and I drove it for 30 min. The car temp did not exceed 190. The car did not die. So I believe the temp was the culprit.

So if I replace items suggested in this previous thread. And still have this problem due to 90 degree temps here in SoCal. How would I proceed then? Obviously it's July and it's not going to be cool outside during the day anytime soon and the Trans Am is driven daily.

Thoughts and suggestions please

Adrian

skibum2100

Hi Adrian,

These hot days are overheating my fuel as well. My problem is compounded by a high flow pump that just circulates more fuel than necessary and continuously heats it up. I ordered a tranny cooler to use as a fuel cooler. I also plan to use temp tape to wrap the fuel lines where they are close to the engine. Hope this helps.

BOSS 357

iTrader: (1)

We all seem to be having the same issue, but it's weird that no one ever finds a real solution. My car isn't stock at all, but my issues are pretty much the same. Here's my post if it helps anybody (or if you can help me!)

https://www.thirdgen.org/forums/tpi/...hing-else.html

As I mentioned in my post, I wrapped the bottom of the tank in heat shield and that did help the volume and temperature of the vapors unleashed when I open the cap. Did nothing really for my pressure loss. I am wondering if I should also wrap the metal lines by the header or even the entire rail. I suppose that would be easier than pulling the pump, but I hate stabbing in the dark.

Eric

skibum2100

Hey guys,

I got a chance to poke around under the hood and found something. The last time I had the intake off, I broke a bracket securing the metal fuel lines that pass behind the alternator. The return line was leaning up against the head, undoubtedly overheating the fuel. I wrapped the fuel lines with thermal tape, but I want to relocate the fuel lines to the back of the engine bay. Today the outside of the tank reached 101F. If the fuel temp goes above 130F parts of gasoline begin to vaporize.

When the fuel gets close to its boiling point and the electric fuel pump pulls a vacuum on the fuel in the tank, it instantly boils at the pump impeller and cavitates. This would cause a lack of pressure to the rail. I will monitor the fuel temperatures / pressures and see what they get to, then post it.

John Galt

I'll be keeping an eye on these threads, I've been having the same problem on my 89 iroc, even after changing fuel pumps, and heat seems to be the only factor that is constant. I hope we find an answer. By the way my pump gets considerably louder when it is happening. Last week my wife was with me, I took a run to the store, and on the way back I said "Listen to that noise, the car is going to stall in 2 or 3 minutes" and it did.

John Galt

Hey everybody, I've got an update, an interesting one also. I went under the hood today to try to get to the bottom of this and noticed that the bolt was loose(actually stripped) that holds the fuel lines, the same bracket that skibum2100 mentioned in his post above. The lower of the two fuel lines, the return line I'm guessing, was loose and laying against the head. This is the front of the head on the drivers side just behind and below the alternator. I did some rigging to bring the line away, at most it's only about 1/2" away but that appears to be the stock location anyway. Went for a drive, high speed with the A/C on. This will usually make the car die within a half hour. After 2 1/2 hours of driving I never had it cut out or even have the fuel pump make that low whine that signifies it's getting close to dieing. While today is not the hottest day we have had in Florida it was hotter than other day's that the car had died and the car was at 220-230 for the whole time which is the same range it has always quit before. I won't call it a success because of one test drive, but it is encouraging, hopefully some of you others will check this bracket and post what you find as this is a big mystery for a lot of us. One thing I have noticed, and why I'm looking under the hood in the first place is that this has got more to do with the engine temp rather than the outside temp in my case. I know the two are related, but with it always in the 90's here I can almost call one a constant.

skibum2100

Hey folks,

I went for a drive today and after ~50 minutes of driving the "vapor lock" returned. When I started the drive the tank was at 80F and after 35 min the tank was 108F. When the tank reached 120, I started having problems. Luckily I only had a half tank of gas and limped to a fuel station to fill up. This immediately dropped the tank temp to 102 and I was able to drive all the way home (30 min). Got home and the tank was at 118.

Obviously thermal tape around the lines isn't enough for me. Maybe it didn't help because the thermal tape is actually touching the head and the lines in multiple locations under the alternator.

My next step will be to remove the thermal tape and ENSURE that the fuel lines are never touching the engine (ie. factory location to the T). I am considering running a trans cooler in front of the rear axle, near where the fuel tank connects to hard fuel lines. I can mount a smallish cooler in this area, and I hope this will cool the return fuel enough.

One thing worth mentioning, the temperature of the fuel rail was 154F. This seems way too hot. Is there a fabric washer I forgot to put under the fuel rail to isolate it from the manifold, or should I get one. I will try to find the hottest part of the fuel system and let everybody know.

aurum_duck

iTrader: (2)

gonna follow this one closely. i have had the same issue for a while now, super hot, supersaturated vapors coming OUT of the tank. dealership said it was a bad valve (hanging off the sending tubes in the back, mounted--but that is for inlet pressure I believe IIRC) and actually gutted the dammmmed thing.... smelled gas like crazy as soon as they did it, so I took it back, bytched them out and got my money back. pump whines/dies, etc, just as everyone else...

i've also wondered why no one has ever figured this one out... but, again, fuel lines are extra close--maybe it's fuel starvation and too much return?? too much output from the pump causing too much return?? I dont know, but hopefully we can all chime in and see where it takes us. i've posted on this topic before, ended up putting a new pump in about every two years or so---walbro lasted the longest but was by far the loudest and hottest.

i'm thinking fuel cooler is a bandaid--they've run for 20yrs like this and no problems.

Going with a FIRST TPI soon, and like the corvettes (maybe we should see if they have ever had this problem??) the fuel lines enter in the back of the rail, not the front. Idiot GM engineers. between this, the filler neck, etc... cripes.


also, what about the H.O. 5.0's that had a fuel boiling issue??? anything related between incidents??

I had a 92RS TBI 5.0 that would warm up in the tank, pump made a lot of noise, but never pressure like this-- the 91Z 350 tpi scares me when I take the cap off, and not to mention it spits gas back out if I try to fill it too fast (aftermarket tank installed)???? I'm lost on this one.

bungo78

iTrader: (1)

Well hopefully we can come to a consensus as too what the problem generally is...

If it is the lines being too close to the head or touching the head. Then this would be the first place to inspect and correct if applicable.

For me. Since the day of my incident, I've been more cautious. 2 consecutive days after the temp outside was still in the 90's. However, I didn't allow my engine temp to get as high to allow the fans to come on automatically. I manually turned them on after 160( I have a 160 stat) and the engine temp did not go higher than 180.

I had no "vapor lock" encounters. Obviously this is just a band-aid approach until I can get more in-depth with the possible solutions. IE: Fuel lines and others....

Since those days, it has cooled to the 80's and I haven't had to run the fans manually and everything runs as it should.

I appreciate the discussion of this topic and hopefully we can all get to the bottom of this.

Adrian

astoneburner

89 iroc 5.7 same issue today temp over 90 loud whining noise from tank can be heard at low speed above the exhaust noise car seemed to run lean a couple of times very excessive pressure in tank ran with cap loose same issue. Pump only two weeks old car cooled down after after sitting a couple hours and noise went away.If anyone finds solution please let us know .
Thanks Alan

John Galt

It's been a few days since I pulled the fuels lines away from the head, I drove it 2 1/2 hours after that and didn't have a problem at all, sunny day mid 90's, that's the run I posted above. After that post I had a reason to go to Daytona Beach that night, about an hour and 20 minutes each way. And it was night so I went for it. Upon arriving in Daytona as I got off the interstate and stopped at a light I could hear a hum from the fuel pump, was a little worried but the engine did not stall then. I only had the car off for about 30 minutes before I started back again. I heard it again at the lights in Daytona before I got on the interstate, and again when I got off the highway to surface streets in my town. The car never stalled, but the hum is louder than usual. I drove it again for a while Sunday and again I can hear the hum, but I'm not stalling yet. I think it's a matter of time though, I don't think it's fixed. Can everyone post anything non stock, maybe we all have something in common. If this is just heat why now, why not in '89 when mine was new? For myself I have no cat and a flowmaster muffler, does it radiate more heat than the stock one did? I also have a cheap fuel pump from Autozone. My mechanic friend tells me that's my problem, and I should get a Bosch or AC Delco. Mine is in tank also, I don't know if anyone here is having this problem with an external pump. There's got to be a common thread here. By the way I got the car 5 months ago and it had this problem along with others. I pulled out the fuel pump and put one in from Autozone and I still had the problem. Thought maybe I got a bum pump, and turned it in for warranty replacement(couldn't get my money back of course) and put another Autozone pump in 2 weeks ago, same problem. There's got to be a common thread somewhere here with all of us.

jhp73

When mine started doing this my pump eventually went out. Put in a new one and no problems until tank gets low. Other than that adding new cold fuel usually solved the problem. Keeping fuel cool is the issue our huge rear hatch windows right over our tanks don't help the issue.

John Galt

Well it happened again....sort of. I took a drive, 90+ outside, A/C on for about 45 minutes or so. Almost didn't know but as I turned into my neighborhood and depressed the throttle it sputtered as if running out of gas. Not exactly like before, it didn't stall, but as I experimented with it found that anything more than 1/4 throttle caused the sputtering and anything less ran normal. Pump was noisy as usual but this was more like being on the edge of pump failure, but not quite there. How long it was going on I'm not sure because the last couple of miles to my house are slow speed and I couldn't open more than 1/4 throttle without slamming into the car in front of me(I rev it when I pull into my neighborhood just to let the neighbors now I'm there, and by the way get out of the street or I'll run you over). Short story, getting the fuel line off the head didn't solve it but seems to have greatly affected it. I'm running it at under 1/4 tank of gas too, but it's on purpose to try to force the overheat, because although I don't normally run the tank this low it shouldn't cause the car to stall when I do.
Another thing, I don't know any friends with a stock third gen that I can look at but is this muffler supposed to be 2" from the gas tank? The back is the only place under the car with enough clearance to drop something if you wanted to, and I'm beginning to think about it.

BOSS 357

iTrader: (1)

My post above details what's in my car, but I'm in this with you guys.

I've come to the conclusion that heat is my problem too. I can idle with the hood open and get it to stay alive for a few more minutes than with it closed. I am going to wrap the fuel lines and rail in heat reflecting material. DEI makes a "boom mat" and heat resistant tape to match. Good for 400* direct and 2000* radiant heat. I've taken everything apart (and dumped a good bunch of gas on the garage floor to boot), I'm going to clean everything and then seal it all up.

If the one poster's heat treatment on just the lines by the head have helped, I bet wrapping the entire plumbing may help more. I also did the underside of my fuel tank as well. That helped greatly the temperature and volume of vapors that come out of the tank when I open the cap.

FYI, if you want to test and have it "do it" quicker, just start 'er up and let it idle for 45 minutes or so. Works for me and there's no worries about getting it home.

I'm going to put the "grade A" effort into this as I like to show my car too. It's going to take me a week or two as I have a couple other things going on as well (don't we all).

I'll post back my results as soon as I can test. If this doesn't work, I'll be dropping the tank for a replacement pump. If that doesn't work I'll have a car for sale.

mblackey

We've had the same fuel starvation issues road racing a 1988 305 TBI. Get to 1/3 - 1/2 tank, go into hard corner and engine loses power or cuts out. It appears the fuel, including fuel in the tank, is heated to the point it cavities in the fuel pump (TPI pump in fuel tank).

Engine runs about 210 (90-95 track temp). We're running headers, and they add a LOT of heat to engine compartment. We added heat shields where fuel lines run in/out of engine compartment. Fuel lines are rerouted and now go to the TBI over left fender and over brake booster. We also run a fuel cooler box with dry ice, but it only helps for 10-15 minutes. The exhaust system exits 2 into 1 in front of the right rear wheel.

We think the TPI pump might be part of the problem high flow demand from pump is more prone to cavitation from heat, high flow also causes more bypass at TBI, which causes more fuel flow through the hot engine compartment.

We also road race a 1989 Firebird 350 TPI with identical headers and stock fuel line setup... no cavitation issues at all...

SO, we think a TBI, especially if running performance mods, is prone to fuel heating issues, even at moderate engine temps. We haven't found a solution.

skibum2100

Hello everyone,

I believe the source of our fuel overheating is two-fold.

Part 1 is a high flow pump puts more fuel through the same space, which results in heating of the fuel due to pressure.

Part 2 is our fuel rail. My rail reached 172F today after a short drive and heat soak.

These two factors are overheating my fuel. I no longer think that exhaust plays a role, because my muffler only gets to 210F and the 2" of air provide plenty of insulation value against heat transfer.

I need to get some heat out of the system and I think a trans cooler is my solution. I plan to run it in front of the ac condenser on the driver side and plumb it inline with the fuel return line.

I hope this can help others.

GOATS2QUICK

iTrader: (5)

im wondering if its the ethenol blend?

mblackey

Not sure the trans cooler will do the job unless you use a very large one. We completely rerouted the fuel lines away from the engine and ran a cooler box, both with dry ice and regular ice. The ice helped for awhile but melted quickly.

Yes, I bet the ethanol adds to the problem. We're going to try E85 with an octane booster and see what happens.

John Galt

Ethanol is the best thing I've heard so far, at least it's something new to consider. I'm not going to look at a cooler as a solution for a barely modified daily driver, I can see it if you are racing, you're building a performance machine, you've made major changes in some way, something hugely different from stock. This thread is going to end up going the way of all the others, fading away without anyone finding an answer. I don't know what to do about it, I don't know the answer either. Here's what I'm going on:

1. I don't have anything fuel related that is any different from the stock configuration, yes I've changed the fuel pump, to an Autozone model, am I to believe that it puts so much MORE fuel through the line to end up returning than the stock? More likely it's an inferior piece of crap, but does not seem to be the cause or a contributing factor. Let's face it, the last of the 3rd gens is coming up on 20 years old, mine is 22, many are 30(although not with TPI)....how many people haven't changed their fuel pumps by now. I'm not a mechanic, but I work with liquid pumping systems everyday in my profession and increasing pressure alone does not make more heat, increasing flow in a fixed size of piping can increase friction but this is negligible in systems pumping 40 to 60 pounds. Honestly, 40 to 60 pounds is considered LOW pressure where I come from and no noticeable heat increase is coming from a few pound increase, even a 20 pound increase. The only factor that could increase heat from a pump pushing more pressure would be that more of the fuel bypasses the injectors and ends up returning to the tank and would get heated again on the trip back.

2. If it's not the fuel pumps, why is it happening now, why not in 89 when the car was new. Why not every car that came off the assembly line. Why not 5 years ago. Why has the car not been doing this it's entire life. There's a component or condition somewhere that is contributing to this majorly, we just haven't figured it out yet.

3. Ethanol is something, it may be way off and nothing to do with the problem; but at least we've thought of something that is different in the past few years that wasn't a condition in the 80's. Yet ethanol is pretty much everywhere isn't it(I don't actually look at the pumps anymore) and you would think every third gen that put ethanol in would do this. Or maybe ethanol isn't at every pump and I should look around a little more and shop for quality instead of price. Who knows.


Bottom line, I don't know what the hell is up with my car, and apparently a lot of cars are having the same issue, and yeah I'm looking a some sort of fuel cooler myself, but I'm just trying to make the car reliable again, I'm still going to look for the real problem. And I'm not dropping this thread until I figure it out.....

Unless I get tired of looking and just sell the car.

Any suggestions?

mblackey

John,

Although we're talking about a racing application, I think the symptoms are the same... just the onset rate and severity is pronounced. Curiously, we don't have this problem in our other car...

It only occurs in this car: 1988 Camaro 305 TPI engine/heads, 454 TBI, headers, open intake and 2-1 exhaust, no emissions, TPI fuel pump, 91 pump octane gas, rerouted fuel lines.

It does NOT occur in this car: 1989 Firebird 350 TPI (ported 1987 Corvette L98), identical headers, open intake and 2-1 exhaust, no emissions, TPI fuel pump, 91 pump octane gas, basically stock fuel lines.

So, with the problem car (1988 Camaro), here's our thoughts:

Bigger Fuel Pump: The bigger pump without a commensurate use of fuel means more bypassing and more heat transfer as the fuel passes through the engine compartment. Our car starts showing symptoms at 1/4 -1/3 tank of fuel. The fuel is either superheated by then (about 1+00 - 1+15 on the track) and/or there's some fuel slosh in turns which uncovers the fuel pickup and contributes to the pump cavitation.

Engine Heat: We've definitely increased engine compartment heat, but we've also taken precautions to reduce it and protect the fuel lines. We're adding header wrap before the next race.

Ethanol: We're in Colorado. They add 10% to 91 octane here. We're also running at 5,000-6,000 ft above sea level. Think this is definitely a major contribution to the problem. We're going to try E85 with an octane booster. We'll let you know what happens.

Mike

GTA90X

iTrader: (2)

Forgive me if I missed it but I don't recall reading about any of you guys checking your fuel pressure. I would try monitoring your fuel pressure as the engine bay heats up. Fuel pumps do some weird things and unfortunately with them it is almost never a case of "functioning/not functioning". It may be that over time the heat is affecting the performance of the pump.

Considering that a fuel pump is just an electric motor, as heat increases so does the electrical resistance. The first thing I would do is put a pressure gauge on the fuel rail so that you can see what is happening when all is good and when things go bad.

Good luck.

mblackey

I'm assuming everyone realizes there's two fuel pumps available, one for a TBI and one for a TPI equipped car. The TPI has much higher pressure. If used with a modified TBI engine, like we did, there's excess pressure which is bypassed through the TBI.

GTA90X

iTrader: (2)

Sorry. Based upon the forum section I just assumed you were having issues with TPI setups.

cayman5reader

Same problem in miami.it is hot!I bought a 89 camaro 350.When i drive it 30 minutes in extreme heat it coughs and cuts off like im getting no gas.10 minutes later i hear a loud pressure release from the rear of the car i think..tizzzzzzzzzzzz.Come back in a hour and it starts right up but the smell of gas is terrible.I changed plugs,fuel pump and relay, coils etc and i was ready to give up till i read this blog.now i see its common.Wtf???? My gas tank must be hot as hell right now!

cayman5reader

By the way what is the difference between tpi and tbi?Somebody here just posted that depending on which you have there are 2 different fuel pumps and one is stronger than the other one and gets hotter faster? Can somebody elaborate on this for me...I have no idea what this means and if one gets to hot maybe i should get the other one.I have a 89 iroc 350 5.7

DD9TransAmGTA

iTrader: (1)

TPI is tuned port injection TBI is throttle body injection, if thats what your asking

310cid

iTrader: (1)

hi i have a 406 tpi and my car is doing the same when it get up to temp the pump whines and its a new pump we been haveing 95-100 hot days here and i dont want to kill my car with these hot days but any way i drive it for a lil while then when i give it more the half throttle it fumbles and donest pick up speed it only happends when the car past 180 degress on temp gauge run fine under half throttle did anybody fine what swrong with pump

310cid

iTrader: (1)

it has to be the heat when i was running str8 headders my fuel pump wasnt whining and i had full power but when i went an got 2 and a half exhuast all the way back with dual i ran into this problem im thinking the heat from headders to muffler heating the tank and fuel lines both thats whats causeing the problem then my intake is hot as the place were bad people go it not helping either my throttle body is to hot to touch when this takes place and that not normal

itsMikey

lol..this **** happened to me twice in the past month or so..once coming back from long beach and once coming back from irvine..luckily i was only 1/2 mile away from home both times..i let the car cool on the side of the road both times for about an hour and it started up fine..i hate it..

John Galt

I have recently been under the hood looking at this again recently, I posted a few weeks ago how I noticed the return line was touching the head because of a bracket and I fixed that. I found that the water hose coming from the front of the manifold up to the TPI port was laying on both fuel lines and moved it, don't think that's gonna make any difference. I did notice like skibum2100 had posted above, my fuel rail is crazy hot and I'm thinking about pulling off the rail and trying to use some insulating material where it bolts to the manifold. Like washers made out of the space shuttle tiles. Another thing I was looking at was the muffler clearance and wonder how much this is affecting it, originally I thought it was big, then I thought it had more to do with the under the hood temps, now I'm not sure which. I have a PT Cruiser and had it up on a lift the other day, and noticed that the exhaust pipe as it goes over the axle never comes closer than 6 inches to the gas tank, and it goes to one side of it and not directly under it, and this is just the pipe going back to the muffler, the muffler itself is further back. Regardless of this clearance the drivers side of the tank is covered in heat shielding. I think that there is an answer to why this is happening and why it didn't always happen in every car, or more likely several small things in unison instead of just one core problem; but that this probably was not well designed by GM in the first place and maybe heat shielding and extra clearance wouldn't be a bad idea.

BOSS 357

iTrader: (1)

In an earlier post, I stated I was going to wrap my engine compartment fuel lines and hope to fix the problem. The short answer is that it did not work. Below are the details of this attempt.

As previously noted, I wrapped the bottom of the tank with Heat Reflective Mat, the results noted in that post. I removed the fuel rail and wrapped it completely (except for the top of the regulator) in HRM, including the connections for the hard lines. I also wrapped the 2 hard lines that reside under the alternator, the rubber lines, and the hard lines back to where they pass by the header. The metal connections at each different line set were left unwrapped. Obviously, my theory was that insulating them from engine heat would cure the problem.

I tested this fix as I have the others: in the garage, with the hood closed, FP gauge attached, WBO2 reading at hand. The difference this time is I put 2 box fans on HI about a foot away from the front of the car so as to give some effect of moving along the road. Admittedly, testing during this heat wave may not have been ideal, but I wanted to be sure that, should this work, it would definitely have been the answer. Those conditions are:
-air temp @ start 96*, heat index 113*, 36 psi on the gauge
-after 20 minutes, the water got to 193*, I turned on the AUX fan for the duration; the O2 correction went from a +7% down to a +3% until the test failed; water temp was 185*
-after 40 minutes, the pressure began to drop. air temp 102*, heat index 116*

Were I driving, I figured I would have gotten an hour of drive time before I had to call for a tow.

Someone above mentioned E10 as a possible cause of our problems. I have done some reading and I think he might be correct. I did not have this problem when the weather was 85* in May. These links have a ring of truth for all of us. I am by no means an expert and do not purport them to be the gospel. I think they contain bits of info that can help us (yes, one is about boat engines), however if any of it is true, I think until E0 is offered again, we may be in for a tough time.
http://www.thehulltruth.com/archive/t-192129.html
http://www.fuel-testers.com/list_e10_engine_damage.html
http://www.laboratoryequipment.com/u...H-Blending.pdf

I am beginning to think it is pure coincidence that immediately after I switched my EFI system, I got this issue. Even before I fired the car the first time, the temperature started hitting well over 90* on a regular basis. For the most part, here in Richmond, VA, we've had only a week or so of temps UNDER 90*since mid-May. I seldom drive the car for more than 30 minutes per engine start. I may run a few errands with a total time out and about of way more than an hour, but the conditions under which I was testing the new EFI were extreme (for me) so that I may verify and feel good about my results. I do feel that I could (and most likely will) continue to drive my weekend warrior on short jaunts around town as I had never encountered this problem until recently (my hour+ test sessions). My dyno trip for the new EFI will probably wait until the weather turns cooler.

Personally, I do not believe my fuel pump is at fault. This is purely E10 and one killer heat wave to blame. I think we all can go back to enjoying our cars in the fall and cussing the Powers That Be until then for the poison they put in the gas these days. But, as always, I'm open to another solution.

John Galt

I'm starting to get on the other side of the fence on this one, after Boss 357's quote, and looking around for the past 24 hours I'm thinking that ethanol is the contributing factor. I should be happy because I wanted to find a reason it is happening now, why it didn't happen 20 years ago, something that is different, and this qualifies as that. It's just not what I was hoping for, I want a part to change, not to redesign the system. If that's the way it's going to be now I guess I should start thinking about the changes. Like someone else said filling it up with more gas stops the problem and buys you another 30 minutes or so before it happens again, that is true for me also. I think the temp of the tank is where the onset of the problems begin, but the engine compartment is the source of the heat, I'm not sure the muffler is a huge factor. I've been thinking of something, I need a better educated opinion on this as this is my first fuel injected car that I ever did any mechanic-ing on, I'm old school 70's chevy 350 educated, and I'm learning the FI thing for about 5 months now. The question is: if the fuel is getting heated as it runs around the engine compartment and between the plenum and intake manifold and then reheated in the return line as it goes back through this area again, would it make more sense to put the pressure regulator somewhere else. At least not attached to the block like it is now, maybe on the firewall; or even better - not in the engine compartment at all. That way the excess fuel returning to the tank would not be getting heated at all before returning to the tank. And next question, if I were to remove the FPR from where it's mounted is there a hole under it or any consequences to that action that I would need to consider. Has any one done this, is there an after market regulator that I could buy, or has anyone tried this and is still getting the same problem. Any other ideas would be welcome. I've thought of the fuel cooler idea like others but I'm trying to think of a way to do this the opposite, just not letting it get heated up in the first place. Let me know what you all think of this.

BOSS 357

iTrader: (1)

Without redesigning the whole system, no, I doubt moving the FPR is going to work. The regulator itself sits on top of a "bowl" with holes on either side for the fuel to flow through; that bowl is part of the rear hard line of the fuel rail.

Overall, heat and E10 maybe the problem. I don't really think the way our cars are setup is the problem that would require redesign. I say that now because we are still early in the diagnosis and resolution of this issue. Obviously, there's more heat than just what the fuel encounters in the engine bay. My insulation trick may have bought some more time but damn, how much cooler does it need to be? (rhetorical question).

I saw that Sta-Bil makes an ethanol additive. I did some digging and found a couple folks that have used it specifically state that it helped their vapor lock situation (assuming that is what's happening to us). I am going to call SB on Monday and ask their opinion. I'm thinking if all I need to do is add a $7 bottle of stuff to my gas at each fill, I'm all over it. I don't want to get too excited about it, but I would think some company out there might be trying to fix this problem with E10. 3G cars cannot be the only vehicles with this issue, we just need to join our voices with whomever else is having this problem to get some results.

BOSS 357

iTrader: (1)

I called the Sta-Bil folks today. The lady basically read the info from the bottle to me and said it was not formulated to help vapor lock. I've been scouring the net for almost 4 hours now and I keep coming up with people saying that Marine Sta-Bil has helped their VL issue. Not many folks are mentioning regular SB or SB ethanol treatment at all. I've read where it won't harm a car engine (boat engines are pretty much the same) so I think I want to give it a shot.

I suppose the only definitive solution for myself, since this is a weekend only car, would be to let the temperatures drop a bit before taking it out. I really was hoping for some magic cure. The naysayers about fuel additives are saying no additive will chemically change the boiling point of this fuel concoction. Most all of the results are from boaters who turn on engine blowers, dump ice water on their fuel pump (much like we'd put fresh fuel in our cars), or open the engine room hatch to get it cooled down.

After my attempt to isolate the fuel lines from heat in the engine bay, I suspect simply letting the outside temp drop may be the best and least expensive solution. If I can find a small enough sample of the Marine SB (blue), I'll try that. I don't really expect it to work, but it seems it can't hurt at all.

Does anyone have any experience with it? I use the red SB now so I can't understand how a higher concentration of additive (blue) will help.

79malbiu

FWIW my car is a non-Fbody & I have the same symptoms but only when sitting in stop & go traffic so im thinking heat soak

Firebat

iTrader: (7)

I think for some of you guys, the main issue might not be heat, but instead gas tank pressure not being released properly. Heat may be making the issue more apparent. I think heat causes the gas to expand and take up more space in the tank causing more pressure to build up. The excess pressure is to vent through the vent line, then to the charcoal canister, then to the outside air (or also back into the throttle body).

I've been trying to figure out why I'm on my 3rd fuel pump this summer and why my new one started whining after 30 minutes of highway driving. I think I have mine narrowed down to the hard line going to the charcoal canister being partially plugged or completely plugged. I took off the hose from the charcoal canister going the hard line and no pressure was released, yet when I take off the gas cap have pressure released there.

Broone115

In one of these threads about "fuel pump whine" I read that someone disconnected all of their fuel lines from both ends, tank and engine compartment, and blew compressed air through them all. They also stated that there was a visible blockage in the return line at the fuel tank (causing alot of pressure as Firebat stated, and if ur canister line is clogged too then there is excessive pressure build up) They then reconnected their lines and said that the whining stopped and hasnt happened since. Now i know this is just for whining but it could be related symptoms.

Also my father owned a 1990 camaro TPI back in the late 90's and said that he couldn't drive that far of distances without pulling over and opening the gas cap to relieve the pressure in the tank, then he would drive again and it would be fine. So yes i too think heat and pressure are to blame.

John Galt

Well I hope to post something useful soon, I replaced my muffler today. I have 3" pipe, no cat, and did have a flowmaster; and the car was so loud I couldn't take it anymore, I couldn't have a phone conversation, had to turn the radio really loud to hear it at all, had trouble even having conversations. I guess I'm telling you this to let you know I'm not going crazy with the gas tank heat issue, I was doing this anyway because of the noise. Short answer is between the different mufflers size and shape and the ability to manipulate the mounts while the muffler was off I went from 2" clearance to about 5 or 6 inches between the muffler and the gas tank. As far as heat transfer goes that should be a big improvement, I think doubling distance in this case does more than double the relative air insulation value, it does more like squaring it or something. Then again, heat rises if I'm sitting idling so we'll see. But the most useful thing that happened today might have been from meeting an older mechanic in the muffler shop who has a hotrod, he told me of a gas station about 15 minutes from my house that sells real gas, no ethanol. I think I'm going to do a little testing with the remaining ethanol blend in the tank before driving out to the station to see if the muffler change did anything to improve the problem, as even if the pure gas solves the problem; it removes my ability to take a trip further than one tankful from home.

1tpi

I have the same problem. so I drove with my gas
cap of and the problem went away, put the cap
back on and it came back

BOSS 357

iTrader: (1)

I have nothing positive to contribute, I'm just complaining now. It's 92*, I put a couple oz of that Starwhatever ethanol problem solver stuff in my tank, filled up and expected to have at least an hour or so of joy riding. Car looked so good sitting in the garage, it was just begging me to be driven hard.

I got a SOLID 20 minutes of drive time before I had to pull over and roast in the sunshine while the car cooled for 40 minutes. I'm so f*****g sick of this!!

Just for own peace of mind, has anyone else removed their EGR? Mine is on the bench and I'm wondering if that may be contributing to the excess heat. I love the EZ-EFI but if not having an EGR means I can't drive it, then it may not be worth it.

jhp73

Yup I Have done the gas cap thing. I agree with Firebat and Broone I think it is a heat and pressure issue And I think clearing the lines sounds like a good idea

John Galt

I get the same results with or without gas cap, the gas cap factor is just a sign on whether your vent tube or charcoal filter need attention. It is not causing the problem.

BOSS 357

iTrader: (1)

Agreed. Gas cap didn't affect my outcome either.

1tpi

True

Chevy86 IROC-Z

iTrader: (17)

I always thought that my FP whine was from low fuel. My fuel gauger doesn't work so when I would begin to hear the whine, I knew that it was time to put in gas. When I got my IROC to run after 7 years of being parked, I had to get a junkyard fuel tank. After I cleaned out the deposits with fresh gas I noticed there was a rattle in the tank. So after inspection, there was a small round disk that fell out. I had no idea what it was so I didn't make it such a big deal. So after re-installing the tank I did begin to realize that occurrence. So after reading this thread, I believe that heat and pressure is the culprit. After all the charcoal canister is suppose to remove all vapors from the tank. But after about 30 minutes of driving while at the pump, there is a whiff of pressure that escapes as I remove the fuel gas cap. I think I'm gonna do the pressurized fuel line process to clear any obstructions. Just not sure when Ill have the time.
Below is the round disk that I was talking about.....

310cid

iTrader: (1)

its that dxxx goverment trying to out law our hot rods lol i read about that in a car mag. i have a question if the fuel mixed with nitrogen would that keep the fuel cooler mix with the e10 cause i replace everything with fuel and canister and would a bigger pump be a solution to keep gas flow from vaporising

310cid

iTrader: (1)

i drove my car few nights ago after it had rained and the outside temp was down to around low 70s and my car ran great for 3hrs of driving then the next day i drove in the daytime thinking the prob was fixed and it came back i convinced that it the temp plus the engine heat

-srs-

Keep this thread alive! My vert is as stock as the day is long and I have the exact same symptoms. Runs fine till it's warm. Lots of pressure at the cap. I also have a faint whiff of gas at the stoplight. I'm going to start watching where I fill up and see if REAL GAS helps. I backed out of taking my car to the Ozarks because of this problem. I want it fixed!

jhp73

Can pretty much garantee it ain't the gas. Heat and pressure caused by the heated fuel are the main issues.
Ok here some new info. I did a little experimenting I put several layers of cardboard in the back area under the rear hatch window and then triple layered my car cover and put it on top. Drove 5 hours in over 100 degree weather with nary a sound from the fuel pump or gas tank. So I would like to know if people who have rear louvers on the hatch window have had these kind of problems in this thread, just curious.

TomV

Have you recently replaced the exhaust?