BOSS 357

iTrader: (1)

The later-year LS fuel tanks have the pressure regulator coupled with the sending unit (in tank). One line in, no return.

John Galt

I'm more interested in the idea of whether the distance would cause any adverse running conditions, if the pressure would adjust quickly enough to the changes between idle and WOT, but the vacuum thing is something I hadn't considered yet. Of course I could use the abandoned return line, it will be cut at the location of the FPR, and run all the way back to the Plenum. Maybe pressure would be fine if I adjusted it a little higher than stock. Don't know.

Just saw your post Boss 357, I wonder if that unit could be installed on my car, know anything about possible conversions? That might just sit in and buckle down in the stock tank, never seen one myself. Or maybe the replacement bought at an auto parts store with the FPR on it might attach somehow. I think this may be an answer that will actually work.

panhead201

theres only one lap that means anything.The last one.

BOSS 357

iTrader: (1)

I think it could be installed on your car, however if you run a TPI, you're in for a lot of reworking. I also believe you have to get the entire tank and in-tank parts together as well. There are a couple posts available that detail how to get a 4G tank into a 3G car.

The biggest issue would be the TPI fuel rail. Only one line coming from the tank and your rail has a return line. I suppose you could plug it somehow. As far as vac lines and throttle response, I think that stuff is contained in the posts. Do a search for LS fuel tank and that may get you going in the right direction.

John Galt

This FPR idea is something I can't do right now, but I think it may be ultimately be the answer. The fuel in the tank gets sent to the engine, and one poster was checking temps and came up with a 187 degree reading on his fuel rail. Not suprised I guess, it is bolted down to the engine which is much hotter. I took a look at mine, the fuel enters the passenger rail, gets heated, goes through the FPR, and excess already heated fuel exits through the return line, which is also pressed against this same fuel rail and gets heated more, and goes back to dump into the tank, gets sucked up again by the fuel pump and goes again. This endless loop is bound to slowly heat the fuel one way or the other regardless of the compartment heat, but all of it together is taking it to a crucial temp, which is theoretically lower now that we use E10. I am going to jack the car up this weekend and look for an appropriate spot for this unit, was already Googling some aftermarket wall mounted units. I could put it right next to the fuel filter I guess but I think closer to the engine compartment is better, I just think that the pressure drop down when throttle is hit may cause a delay before the FPR opens up if I floor it suddenly. Whereever I do it, I should virtually eliminate fuel temp rise as long as I keep it out of the engine compartment. And where ever I put it I will be cutting the return line to tie in and I will be left with the other side to use as a vacuum line. It almost seems perfect, I'm just running it through my head over and over looking for problems. One question, is anyone reading this post with the problems I'm talking about running an alternate FPR, one that doesn't let the fuel pass through the rail and heat up before going back to the tank? And if so where is it mounted on your car?

RBob

iTrader: (1)

The return-less LS1 system also run 58 psi of fuel pressure. This is to prevent the fuel from boiling in the rails.

RBob.

Chevy86 IROC-Z

iTrader: (17)

John Gault, I think you're really onto something here. But there is one question that is bugging me. If you do tap the return line into the feed line, in between the outside mounted FP and the tank, won't the excessive amount of heated returning fuel overcome the amount of fuel being pumped to the engine, begin to be sent back to the tank viia feed line?

John Galt

I'm not sure I understand the question, If I theorectically put the FPR on the frame next to the filter, about 2 feet from the tank, the excess fuel would just turn right around and go back into the tank, never getting heated in the first place. I would only cut into the return line to use the couple of feet of it that go back to the tank. I would be left with only 1 fuel line going to the engine compartment, and nothing returning to the tank. I do propose however cutting and capping the return line from the existing FPR right where it clears the fuel rail, and instead of abandoning the line, putting an adapter on it and using it as a long vacuum line to power the new FPR. After all I'll be left with a long empty metal tube that goes from the plenum where the vacuum source is; back to the new FPR which is where I need vacuum to control this. I don't see any downfalls, except I don't have the money presently to attemp this. Couple of weeks and I'm going to try it though. I think this is the solution to the heated fuel problem. Eliminating the return line will leave only the muffler under the tank as a source of heat, and that could never raise the temp enough to overheat the fuel pump.

Chevy86 IROC-Z

iTrader: (17)

Sounds plausible. That is a huge risk John. Are you willing to hack the fuel system for a solution that sounds good on paper?

Orr89RocZ

iTrader: (20)

I may be thinking of this wrong, but I'm not sure regulator location would matter.... either way the fuel is sitting in the rails under pressure. Pump supplies gas to the rails and it hits the regulator which is a restriction that backs up flow, creating pressure. Then it slowly passes through the regulator back to the tank. Put it at the engine or at the tank shouldnt matter, the fuel is still under pressure in the entire system and sitting in the rails for some bit of time.

Now I havent had a problem with my system as I have twin intank walbros but only 1 operates in normal driving. I have a 4th gen tank but its still a return style. I have a regulator mounted about a foot off the rails, so the line feeds driver rail, crosses over to passenger side and then exits about 12" of line into the regulator mounted on the firewall (illegal for nhra but oh well) and then back into the tank. The lines are not the stock lines but braided line. They follow the stock path tho but come right behind my downpipe. I have the lines wrapped, and a heat sheild blanket in front of that to radiate heat away. I know my engine bay gets HOT with twin turbos and alot of exhaust piping laying around. My shock tower caps are melted, wires are melting, and paint on the engine bay fender wells is bubbled. Havent had an issue yet on my longest 45 min or so drive on a good hot PA day.

I do not have exhaust under the tank either tho so that helps alittle on the heating department.

When it was bone stock but with catback/headers, original fuel pump, it didnt have issues like described here. I took that on a 1.5 hr trip July 4th weekend and it was abit warm out (PA warm), but then again not super hot like this august heat wave we are having.

Its likely heat issues but not sure a regulator move would help.

1989karr

I kinda skimmed through the post but did anybody try replacing or getting rid of that plastic valve thats mentioned in the "fuel boiling" thread? Seems like it could be a potential solution??

Chevy86 IROC-Z

iTrader: (17)

PA Heat Wave? Go to the weather channel and put in my area code (92250). Now my local heat is not a heat wave, its a normal summer day temperature ( http://www.weather.com/weather/tenday/92250 ).

Chevy86 IROC-Z

iTrader: (17)

Orr89RocZ, so even wwhen you had your set up stock, you never had the issue of FP Whine?

John Galt

I am not saying that a FPR move would lower any of the temps of the gas in the rails, or in the lines going past the exhaust manifold, or anywhere in the engine compartment.

There are more than 1 line of thought on this problem. There are those who think the gas is too hot and vaporizing in the rails. There are those that think the higher temperatures are causing a higher current drain than the fuel pump can handle, and that is why the fuel pressure drops. Then there are those like me that think the fuel pump is just overheating from the temperature, or that the gas is vaporizing in the pump impeller, either way creating the same problem, pump starts whining as temp rises and eventually stops pumping.

The temp of 130 degrees fahrenheit is mentioned in a few places in the thread as a vapor point of the new ethanol gas, but I don't put too much worry about that as I'm sure we're well over that in the fuel rails themselves.

Here is the thing: If I lower the temp of the gas in the tank, I'll have no pump whine as it is temp related. If I avoid the whine, I avoid the failure. I have no regard for what the temp of any portion of the fuel system is except the fuel in the tank. This is where my noise is. Dumping new fuel in the tank shuts it up, which pretty much confirms it's tank temp triggering the failure. And if I control tank temp, I'll have it solved, in my opinion anyway.



And Chevy86 IrocZ----Would I hack up my fuel system for a solution that looks good on paper?

Definitely, I'm that guy. I diagnose liquid pressure issues of a different sort in my normal line of work and frequently work with metal tubing of the same size as in this car, I have no fear of screwing it up, or at worst having to put it back like it was if it didn't work. Other people use these external FPR's in the same way I'm proposing, just bolted on the wall of the engine compartment, mine will be hooked up the same, just a few feet further away.

BOSS 357

iTrader: (1)

A week or so ago, I mention a couple of tests a fella at Blowerworks had me perform. He said to pinch the return fuel line and see what happens. What happened was really nothing. I got no spike in fuel pressure, thus eliminating my regulator as the source of my pressure loss. Couple that with my voltage tests a couple months ago (which yielded no voltage drop) and the fact that my entire underhood system is wrapped, and that leaves only one area that can fail. That is the submerged rubber fuel line in the tank.

I replaced that 4 1/2 years ago when the pulsator failed. Somehow or another, the hose has degraded or the clamps have come loose, thus resulting in the pressure loss. We all know about what E10 does to rubber; we all know that when something heats up, it expands. So if I have a crack in the hose due to E10 or whatever, then as the tank gets warmer, the crack opens more and loses more pressure. What's worse is that when my car is just past warming up (which is when I did the this test), I had no pressure jump when I clamped the return hose. Apparently, my problem exists ALL the time and is exacerbated to the point of failure when it gets hot. One would think that I'd be able to spot the issue rather quickly when I pull the sending unit out of the tank. If that's not the case, then a new pump & hose will both be going in.

Odd considering everything I've done to avoid dropping the tank has led me to the fact that I'll be dropping the tank in a couple weeks to examine the hose and pump assy.

I've been wrong just about every time I've prognosticated about this issue, but I'm running out of items to blame and have arrived at the last two (pump & hose).

Have any of you checked the submerged hose or pulsator (if you're still using it)?

Chevy86 IROC-Z

iTrader: (17)

[quote=John Galt;5021449]I am not saying that a FPR move would lower any of the temps of the gas in the rails, or in the lines going past the exhaust manifold, or anywhere in the engine compartment.

There are more than 1 line of thought on this problem. There are those who think the gas is too hot and vaporizing in the rails. There are those that think the higher temperatures are causing a higher current drain than the fuel pump can handle, and that is why the fuel pressure drops. Then there are those like me that think the fuel pump is just overheating from the temperature, or that the gas is vaporizing in the pump impeller, either way creating the same problem, pump starts whining as temp rises and eventually stops pumping.

The temp of 130 degrees fahrenheit is mentioned in a few places in the thread as a vapor point of the new ethanol gas, but I don't put too much worry about that as I'm sure we're well over that in the fuel rails themselves.

Here is the thing: If I lower the temp of the gas in the tank, I'll have no pump whine as it is temp related. If I avoid the whine, I avoid the failure. I have no regard for what the temp of any portion of the fuel system is except the fuel in the tank. This is where my noise is. Dumping new fuel in the tank shuts it up, which pretty much confirms it's tank temp triggering the failure. And if I control tank temp, I'll have it solved, in my opinion anyway.



And Chevy86 IrocZ----Would I hack up my fuel system for a solution that looks good on paper?

Definitely, I'm that guy. I diagnose liquid pressure issues of a different sort in my normal line of work and frequently work with metal tubing of the same size as in this car, I have no fear of screwing it up, or at worst having to put it back like it was if it didn't work. Other people use these external FPR's in the same way I'm proposing, just bolted on the wall of the engine compartment, mine will be hooked up the same, just a few feet further away.[/quote]

Much respect John. I like a guy who is not afraid of jumping into a problem with expectations of a successful outcome.

As you've already know, I still have my pulsator in place. I dont think a drop in pressure is relavant to the FP Whine. But then agian, it may be the case in your situation. Its obvious to everybody that the FP is whining. Again in my case, mine whines when the gas level is low. I always thought that the FP was sucking up air because the whine was noticable when I would stop or go (fuel swooshing around). But now that I think about it, it may be a case of excessive heat. My whine does go away when I fill her up. But the question remains. Why does my whine go away? Can it be the cooling effect of fresh gas, or can it be because my tank now has a proper level of gas?

I made a new thread a while back in which I titled "Any original 3rd Gen owners, we need help". But nobody seems to post or reply to the thread.
https://www.thirdgen.org/forums/tech...l-3rd-gen.html

BOSS 357

iTrader: (1)

I've had that problem many times. I sometimes have to ask a respected member or two to read my post and comment and usually that gets things going.

Have you considered replacing your pulsator with a new one or deleting it altogether?

I can hear my pump talk to me all the time. I'm not bothered by it, perhaps it's not as loud as yours. I have no pulsator and SHOULD hear it. With you running a pulsator, you SHOUDN'T hear it. I wonder if your P hasn't begun to die?

Chevy86 IROC-Z

iTrader: (17)

Maby. IDK. I will have an answer though when next income tax season comes. Im gonna buy a new sending unit. My fuel gauge doesnt work.

T/Atime

fixed my car!!
had this same problem for too long!

The last thing i replaced was the fuel pump (walbro 255). Car runs great. i fired it up after months and months of this crap and hardly think about it anymore.

Before the fuel pump was replaced i changed:
filter
afpr
added a fuel guage on rail
relay
added heat wrap to headers

important note!
when i fired my car up with the new unit the fuel pressure was at 51psi at idle and 55psi with vac disconected. the old one was set at 43psi. this told me i might have hit the nail on the head. so i adjusted my fp down to 41psi and with vac disconected it reads 47psi.
I MIGHT HAVE BEEN RUNNING MY OLD WALBRO FP AT TOO HIGH PRESSURE. Too much restriction might have lead to a early death. now i keep my tank above half always.

John Galt

I have a pulsator, and I hear it, I thought of removing when I replaced the fuel pump the first time, and the second time, but I didn't. Probably will if I'm in there again. But I have an access panel so it's no big deal. I do not have a whine unless I've been running it for over a half hour on a hot day, and when I fill up gas it stops. I have encountered the whine with 3/4 of a tank of fuel, but it takes much longer to arrive, and same thing though, if I top it off, it goes away. And it goes away instantly, I know, I don't actually turn the engine off when I pull in to get gas, I know people don't care for that, but I'm old school; I'd probably do it with a cigarette hanging out of my mouth too but the other customers tend to freak out.

T/Atime

before i ordered a fuel pump i wanted to replace the pulsator valve. i made a fuel pump access door, best mod to date on my car. research this (tin snips are the only way) turned out to not be the pulsator valve. just a fuel pump for me.

still no answer why it failed me with 15,000kms on it (walbro 255). like i said above i did not have the pressure set right for the entire time time from stock to high flow.

Chevy86 IROC-Z

iTrader: (17)

Yup. The cherry on the cigarette isnt even hot enough to ignite gas vapor or spilled gas. Some people are just too gullable. Sometimes when I get out of my car (1 of 3) with my cell in my ear, the cashier sometimes tell me to get off the cell while pumping gas. I then ask them why and what happens. They usually dont know what to say. They just stay quite. I tell them to look at Mythbusters (in which they verified that a cigarette cannot ignite gas and cellphones dont do nothing around electronics).

Chevy86 IROC-Z

iTrader: (17)

So your initial problem to the whine was an incorrect fuel pressure. Then your FP went bad. Then you adjusted the FP with your AFPR. Then you replaced the bad FP with a new FP?

Chevy86 IROC-Z

iTrader: (17)

Is this the same FP you got? ( http://www.google.com/products/catal...d=0CI8BEPMCMAk# )

T/Atime

yes kind of...
the wine is a normal sound, its an electric pump.

it was the bad performance that made me want to verify my fuel pressure. once i installed the guage it read 30psi. so i did my best to raise the pressure but did not increase past 40psi. so i ordered a new afpr. this one was able to give me 43psi. still not running at 100% at this point. now the car is starting to die, stall, fuel boiling. so started to check evap system, voltage, filter, relay

last just a new pump, running the correct fuel pressure with new filter.

ill try my best to share my experience and not lead you guys down the wrong path as this problem might surface in the future again. maybe ill be working on pump no. 4 soon

Chevy86 IROC-Z

iTrader: (17)

The whine Im reffering too is the lower pitch tone, not the common suttle whine. But anyways, the link I provided above, is it the same FP that you got? I have the cheap $52 Airtex FP from Autozone in mine.

T/Atime

could be? this was 4 years ago sorry! it was a walbro 255 is all i remember. the current pump is from thunder racing "racetronix" 255 with the wiring kit... just using the pump with factory wiring because im at 13volts

1989GTATransAm

iTrader: (3)

I bought my 1989 GTA Trans Am brand new and of course have owned it since. I have not experienced any fuel pump whine. With the horsepower increases over the years I have had to replace my factory fuel pump. I am currently running an AC Delco EP381 fuel pump at 58psi with no whine from the pump. Then again my hearing may not be as good as it was 20+ years ago.

Eightyninef

I have an all stock 89 TPI, original owner. 80,000 miles. NEVER experienced this problem.
#1) keep the tank full. which keeps the pump cooler.
#2) all these cars starve for gas under certain conditions, less than 1/4 tank on hard turns. the car starves.
#3) yes I have new injectors, and a 1LE fuel tank, and new fuel pump, and 1LE fuel sock. my car does not starve under 1/4 tank. I can run it down to the last drop.

and I run the 10% ethonal.

Chevy86 IROC-Z

iTrader: (17)

. The other day I was looking at youtube videos while my wife slept. She got mad and told me to use her Iphone earphones. So as I plugged them into my laptop, I noticed only one side was louder than the other. COme to find out, the earphones where bad. I thought I was loosing my hearing.

Anyways, 4 years is a long time and memory does fade. I dont even remember which of the three relays is my FP Relay. I replaced all 3 relays 1 1/2 years ago and I have since for gotten which is which.

Orr89RocZ

iTrader: (20)

In all fairness, it was over 106 in PA for a few days thats abnormal and its a very humid heat too but normally when I drove my car up there, it was in the high 80's with good humidity so the index was in the mid lower 90's. I run the same E10 pump gas as anyone else too.

I never had a fuel pump whine in that car. I had a flowmaster 80 series right under the tank too. It was all original as far as I could tell when I pulled it out about 140-150K miles? Cant remember exactly. Never had a problem after that with the racetronix walbro 340M pump either, but I didnt run a muffler under the tank after that either. Most of my trips were never longer than 30 min. I did drive my car down to a shop an hour away through traffic as well and it did fine but it was only low 80's that day. Ran great.

The new setup did not have a pulsator, but did reuse the stock rubber insulator cover on the pump. The pumps make a little noise when running but I couldnt hear the over the exhaust while running. You hear the pumps fire on when you "key on" but after that, theres no noise.


I agree its a heat problem and it may be with the pumps themselves. Quality on pumps may have gone down in the last few years and now overheating. I replaced my pump back in like 2005-2006 maybe?

Chevy86 IROC-Z

iTrader: (17)

Eightyninef, Thanks for the reply man.

Thats one original owner that never experienced the problem.

RBob

iTrader: (1)

Actually, make it two. I didn't reply since I've never had the issue. About 120K on a '92 with the original factory pump still in place. Tank has never been out.

Even back in the heat wave (I'm in eastern PA), hour long stop & go drives the pump stayed quiet (twice: out, stop/visit, & back).

RBob.

Eightyninef

My gas tank was replaced because of the filler neck recall. But I never had that problem at all.

Zig

Wow. I have the same problem. My car is relatively stock 91 Z28 350 with a 3" exaust, magnaflow muffler, Walbro 255 FP, Crane Cams AFPR, and MSD ignition components(6a and coil). The Walbro is the 4th fuel pump in 5 years (first Walbro though). I have enough pressure on the tank when I open the gas cap that it would blow the cap off if I kept uncrewing it. I live in Fort Worth, TX and it's been hot, but have had this problem for a while. It started when I lived in Camarillo, CA.

Not sure what the fuel rail temps are but will start checking. However, one time I had the problem, I checked the fuel pressure and the gas was HOT. The last time I had the problem, I relieved the pressure from the tank and in about 15 minutes started right up. I didn't drive it though. Just started it and parked it back in the garage. THe fuel pressure is set to 43psi without the vac line connected. The FP is less than a year old. Same symptoms as everyone else with regard to fuel level. Runs longer when full which I would agree points to a heat issue with the fuel. Also, when it's "broke" the FP is not running. When it does start running, and the key is turned on, I get a whine but it flucuates in pitch.

I Guess I'll start by checking the lines to the charcoal canister. I'll keep this post bookmarked and am looknig forward to what 357 Boss finds inside the tank with the fuel ine. And I thought I was alone...

GTA_Notch

I'm also really glad to hear I'm not alone with this problem, I just wish everyone was having better luck! My car likes to lose power and stall on the highway after about an hour or 90 minutes of driving. Interestingly, it'll start back up and run fine again after a couple short minutes. My '88 GTA is mostly stock, it has a 3" catback and lord only knows what the PO's did with the fuel pump.

Just wondering though, has anyone asked GM what might be going on? I probably deserve a stupid answer for that stupid question... Also, if we think ethanol fuel could be causing issues, has anyone done research on Brazilian cars? I don't know if F bodies made it to Rio, but I bet someone there has had to figure this out. Anyone speak Portuguese?

Chevy86 IROC-Z

iTrader: (17)

Portuguese, I don't know if its close enough to spanish, pero si necessitan alguin para hablar en el espaniol, pues yo puedo communicar con uno que nos pueden ayudar.

jhp73

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.

jhp73

oops bump topic somethings weird here Are their two threads on this topic ??

jhp73

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.

jhp73

yup the whole system 3"pipe including adding smog legal headers

Orr89RocZ

iTrader: (20)

I just thought of this...has anyone tried this higher pressure on the thirdgen systems? If heat is causing fuel to boil, perhaps this higher pressure can help solve some of the problems? Higher pressure should handle the higher heat loads.

Chevy86 IROC-Z

iTrader: (17)

In your signature block, the International Racing of Championships does not apply to the 5th Gen Camaro.

Chevy86 IROC-Z

iTrader: (17)

Yes. In an other post, a member had his fuel pressure about 50 lb. He said that he had FP whine. So (IIRC) he bought a AFPR and lowered his pressure and his whining went away.
https://www.thirdgen.org/forums/post...155-post3.html

TTOP350

iTrader: (8)

Its been awhile since i read this but my random thoughts
GM tested these cars in dessert type heat when new and with high miles. The had a fix for the carbed cars for fuel boiling. Nothing for the Fuelie cars that ive ever seen.
Some pumps Ive changed out will put out psi but not the volume of fuel needed. Some pumps whine some dont. Most pumps do whine a bit..
Those cheap autozone airetex pumps are junk.. do not use!
I run 51-2 psi and have never had a issue with stock pump/pressure or the 255 pump in tank now.
So is there a problem with pumps or is it ignition/electrical components breaking down due 2 heat??
Or is it somthing simple like a bad connection causing the pumps to not get correct voltage or old wires heating up and causing resitance?
I know this sounds hard and or costly but take a drive with extra dizzy,a new pickup coil, when you have the prob,swap it out then drive. Also do that with the ign mod and regular coil.. but do them one at a time you may find your problem.
Ive changed MANY ign coils out for overheating even in the winter! I had one that would fail like clockwork at 45mins every time!
Make sure the vent from gas tank to vapor canister isnt plugged up...
This problem has to be somthing super simple!
Deep deep thoughts by Jack handy..

Chevy86 IROC-Z

iTrader: (17)

what does the ign coil or dizzy have to do with the FP?

T/Atime

when i first experienced a power loss i went to my friends house and put my car on a scanner, at idle it ran fine. We took it out on the hwy, and i started to become lean at high rpm.

to keep a closer eye on this problem i mounted an autometer guage on the fuel rail. this told me later that when this problem would show its face i had low fuel pressure. if you dont have a guage you dont know what is going on with your fuel.

why would i start checking ignition and other components when my fuel delivery is not preforming!!

yes you need to ensure proper voltage. when my car ran like crap i jacked up the rear end and measured voltage, i dont remember exact values but it was more then 12.5vdc so this was good enough for me. when i pulled out the pulsator valve in my car i also tested for obstructions in my charcoal lines, i was able push air with no problems. Attachment 225222

Attachment 225223
tin snips makes this job clean

DENN_SHAH

iTrader: (1)

i figure i will go a head and toss in my 2 cents worth.

when using good quality parts, the heat has never been an issue with fuel injected motors.
pressure in the fuel tank has never been an issue as far as performance goes.

most in tank pumps can't pull fuel very good.
this is more of a cool/cold temp problem, but it can happen during warm temps.
a vacuum in the tank has been an issue. i've seen a few cars where the vent line was clogged or crushed and it had a bad gas cap that after driving for a while caused fuel delivery problems. the more fuel in the tank, the faster the problem would show up.


being an old wrench, i worked on these cars when they were new.
i was able to hear the in tank fuel pumps wine with the motor running, even on cars in for their first oil change at 3000 miles.
with some type of aftermarket muffler, the exhaust was usually enough to cover the pump wine with the motor running.
it always kind of irritated me, but eventually i got used to it, and even used it as another tool. turn the key on and listen for the sound the pump made. i learned what was normal and what wasn't.

things that can cause the wine to be louder than it should be, the fuel pump being improperly installed such as the pump touching any of the metal components on the sending unit or in the tank. the rubber isolator at the bottom of the pump being worn and letting the pump move around more than it should. the rubber cover missing from the pump body.
high fuel level helps to dampen the sound from the pump. with the tank low, its more like an echo chamber.
a dirty fuel strainer, always replace it with a new one.
cheap, poorly made pumps can actually be louder than an old worn out factory pump.
some of the shops i've worked at looked for every way to increase profits, if that meant using a cheap pump but charging the same price as for an OE replacement, so be it. i didn't stay very long at those places.
the quality of the factory pumps very well may not be what it once was.

multiple pump failures are usually caused by trash in the tank. a good off vehicle cleaning usually takes care of it.
i don't know if they still make it, but GM used to have a severe duty pump that was designed for use where the gas quality was questionable.
IIRC, it was around $50.00 more than a stock replacement.
it was also a little louder than the stock replacements.

now that im older and my hearing isn't what it used to be, i can't really hear the pump wine unless its pretty loud.

i feel this should also be mentioned in this thread.
there was a TSB many years ago, those in-tank fuel dampers that GM used should be thrown a way any time you find one.
use the replacement high pressure fuel hose that comes with the new pumps.

Chevy86 IROC-Z

iTrader: (17)

O hell no!!! A hack job!!! I take pride in my 86 IROC. I dropped my tank 3 times in 2 months. Did I think about cutting a access hole? Yes. Why didnt I? Because it takes the fun out of restoring my very own car. O'well, everyone takes pride into their car. I preferably like the thrill of doing a job correctly.

T/Atime

hack job? my work? dude if you dont mind dropping your tank 3 times in 2 months pull your tank all day long, i really dont care. if someone out there is still working out problems with there fuel system and was interested in a alternitive to changing pumps, this can be done in 25mins. ITS NOT FOR EVERYONE! I pulled off this info from a minty TTA with exact measurments with no quess work.

im not here to pull this thread off topic by making it into "smart clean idea vs do it right or dont do it at all" topic.