jhp73

If your asking me? Yes, from new headers all the way back to new flow master with 3" tube. I also had a new fuel pump put in and thankfully after all that no problems as yet. Oh also new fuel filter and new fuel pump relay. One of the earlier posts talked about lines being somewhat blocked so he blew them clean with air. It must be related to an aging issue(that involves heat and pressure) because there is nothing I have found about 3rd gens having this problem when new.

310cid

iTrader: (1)

ok i replaced the fuel pump strainer and the o seal and pulsator in fuel tank and i dont hear the whine any more and car runs fine i also replace ignition mondule was making my car stall when hot and would start but it finally went out but its only a couple of months old but any ways i seem to have solved my prob for the time being next is new coil

310cid

iTrader: (1)

also cut huge hole in heat to extract heat under hood i have a scoop

Chevy86 IROC-Z

iTrader: (17)

Sounds like this guy has had a little too much to drink.

TomV

Has anyone having these issues replaced the fuel regulator?

Chevy86 IROC-Z

iTrader: (17)

Yes. My FPR is about a year and a half old. Still does the same whine as it did before i replaced it.

skibum2100

Yes, my fuel pressure regulator diaphragm is only 4 months old and I am having a similar problem.

-srs-

I don't wanna bunny trail this thread but has anyone swapped their ICM? Seems I remember some threads about heat problems with them...

Any way to log what's happening when they die and won't restart till cool?

Chevy86 IROC-Z

iTrader: (17)

How is the Ignition Control Module relevant to the FP issue?

TomV

On my firebird this problem doesn't happen during the night, has anyone tried replacing the thermostat and temperature sensors?

-srs-

Are we even sure it is a FP issue? I'm just spit balling. There's a lot of chatter about this gremlin.

Chevy86 IROC-Z

iTrader: (17)

Again. Not relavent to the topic. The temp sensor and temp sender are not related to the FP. Temp sensor tells the ECM the temp of the coolant. THe Temp sender goes to the temp gauge.

Chevy86 IROC-Z

iTrader: (17)

Its pretty much a shot in the dark. There is no hard proof of having this issue solved.

BOSS 357

iTrader: (1)

Yes, I am almost certain it's a fuel pressure issue. I've watched my fuel pressure gauge tell me that my fuel pressure is falling to where the car runs as described in any number of previous posts.

The fella who says driving at night helps, is supporting the theory it is somehow heat related. Just think, when Halloween comes around, no one will have this issue until springtime! We can then all enjoy our cars for a few months before we have to revive this thread for next year.

Chevy86 IROC-Z

iTrader: (17)

My FP whined at 3:30 am in last December(2010) which of course is an average of 40* F. So this is one tough cookie to diagnose. Unless I have a completely different issue. But hey, we are in this together. Any other possible explainations?

BOSS 357

iTrader: (1)

Do you have the loss of pressure? If not, then you have a different issue.

My pump wines too. Usually that is a product of the aftermarket pumps, you've eliminated the pulsator, and/or the pump doesn't have the sleeve on it to keep it quiet. I'm not bothered by it. When my car looses pressure the wine starts to die off. Once I get below 20 psi, the wine is almost gone. That tells me it's not sending fuel through for whatever reason. My voltage stays the same no matter what it sounds like. After the cool down period, I get the noise and the fuel until it gets hot again. Rinse & repeat.

I think the noise may be a clue as to whats happening inside the tank. My thinking is that if I can get one of the mfgrs of pumps to say and give me some reasonable evidence that their pump is not affected by heat, either thru hot fuel or external radiance, then I would buy & install that pump. Edelbrock and Walbro don't seem to have the answer. (some of you may be running those and have no problems, don't shoot the messenger)

I'm currently having an email discussion with Racetronix about their Walbro pump (which one poster has in his car and is not having this issue). Racetronix says that their pump probably isn't the solution since it is, well, a Walbro. I'm still waiting for Aeromotive to get back to me.

It looks to me to either be a) the E10, simply because we didn't have this issue 10 years ago or b) the pumps, because something is causing them to overheat (the gas? or this hella hot summer we're all having). Also of note, this happens more to modified cars (like mine) and less to stock cars. The car hasn't changed in over 20 years. The gas has. Pumps are newer. My pump appeared to work fine in years past, what's changed?

darbysan

This is just a shot on the dark, but I have seen problems with the little piece of FP hose used in the tank to connect the FP to the sender. It requires a special type of FP hose that is submersible( spec'd as SAE30-10). If a regular FI hose has been used, it might present a deterioration problem. I have seen these hoses develop a split, and the FP pressure therefore drops. May or may not be heat related.
I have also seen the correct FI hose supplied with a new FP, but the hose was so old and brittle I was afraid to use it.

skibum2100

It happened again......after a 1 hr drive and a 30 min idle test.

Even with manual-override for the fans and a tranny cooler plumbed inline at the fuel return hose under the hood, the fuel eventually overheated. The tranny cooler was 7" by 9" and it wasn't enough to get the temps down. Even with boths fans running full blast, it overheated.

The only thing I can add to help is a fan shroud, but I will have to fabricate one.

So, a tranny cooler isn't enough. This is a tough one.

Chevy86 IROC-Z

iTrader: (17)

Wow. You put a tranny cooler inline with the fuel return line? Thats ballsy. But I give you props for the attempt. You must consider the muffler too. I honestly think the tank is too close to the muffler. Think about it, heat rises. So when you stop and go, stop and go, stop and go, the heat is gonna rise onto the heat shield. The heat shield will in turn heat up and radiate heat up onto the bottom of the tank. Now if our fuel tanks had some form of cooling fins or heat sink (virtually impossible with the compact space), then maby, just maby the temps would be lower. If you really want to try something outrageous, I would suggest making a spoiler to draw air up onto the front bottom of the tank just like the front valance (black flap under the radiator). Maby even modding a small cooling fan in front of the gas tank so that the air can flow in between the heat shield and the bottom of the tank. Just a thought.

BOSS 357

iTrader: (1)

You must be applauded for the valiant effort. Man, if you can't physically cool the fuel, I cannot imagine how else to solve the problem.

For the post above this, my exhaust dumps before the axle (2 chambered exhaust tubes), so there's no muffler below my tank. I removed the heat shield and wrapped the bottom of the tank to boot. That didn't solve the problem, but it did cool the temperature and quantity of vapors coming out of the tank when I opened the cap.

Firebat

iTrader: (7)

I still think it could be a vent/vapor issue for some of you. When temperatures increase, gasoline expands in both liquid and gas form making the vapors or vapor pressure build up. Plus, I would think some heat would be released with the vapors also. Even with the gas cap off, it might not be enough to vent vapors on a 100 degree day with an in-tank pump setup if something in the ccp setup is blocked.

I have the hose going to the charcoal canister on mine hooked up directly to the hardline in the engine bay and yet smell no vapors on that hose when I remove it. However, after I replaced the ccp valve(and now bypassed it) the vapors did decrease some but still have fuel pump issues even on a 1.5hour old pump.
In the pic below, there is a rollover valve in the sending unit? A rollover valve is supposed to work by not letting fuel go to the engine bay if the car was ever flipped over in an accident. This valve goes to the ccp which vents vapors. I've looked at mine and I think it moves way too freely. This means it would try to close when excessive pressure builds up and not do its job of venting vapors. Anyone tried replacing this part yet? I can't find the part anywhere individually so I assume the only way to replace it would be by buying a new sending unit assembly. I'm also thinking about just removing it but don't know if that would be the smartest move. I somewhat tried taking it off but didn't want to budge.

BOSS 357

iTrader: (1)

I replaced my sending unit, fuel pump & removed the pulsator entirely in 2007, brand new GM s-unit. I've put around 5000 miles on it since then. I'd hope it hasn't gone bad that fast.

Chevy86 IROC-Z

iTrader: (17)

This topic is a tricky one. The problem is there infront of our noses. But where is the question. Is there any original owners here in this thread? If so, did this problem occur when you bought your thirdgen 2 decades ago? I"m gonna start a new thread requesting for original owners to checkout this thread. What I want to do is ask if this phenomenom occured when they bought their TG. If the problem occured after certain years, then we would know that this is a overlooked issue in part of GM.

80schild

iTrader: (5)

Is it happening to TBI cars too? What about the V6 cars? If it isn't happening to those cars then the problem must be under the hood, not at the tank.

Chevy86 IROC-Z

iTrader: (17)

Kind of like collateral damage or the domino effect. A problem may be "here", but its causing a problem "over there".

BOSS 357

iTrader: (1)

My Theory

After almost 3 months of chasing this issue and countless posts to the forum, I have come up with, if not the cause, some talking points.

The Heat
So, why has TGO been lit up with this problem, seemingly more than it usually does? The most obvious issue is that over MOST of the country, we have been in a killer heat wave since the middle of June. Scroll back through the posts and I bet (I didn't look) that the majority of the problem have occurred where the heat has been the worst: Mid Atlantic, Mid West, Texas, areas like that. Yes we have heat waves, but the length and temperature hasn't been seen like this in some time. As the weather cools off, most of us may have our problems subside. I took the car out for about an hour and a half on Friday running errands; temperature was mid/upper 80s. No problems. It seems like we will start to get our cars back for the cooler months.

The Engine Bay
This, I think, is the single most important part of the equation. We can idle for 45 minutes, car dies. Idle with the hood up and get over an hour. We can drive the car around town for about that same 90 minute time period, car dies. Get on the highway, all good. Exit ramp and stop light = sputtering car. Why? Plenty of air flow at highway speed to countermand the heat buildup. Case in point; when my car was on the dyno, it ran for an hour with the hood UP and a huge box fan keeping it cool. I had to start it up to go home right? Well, the tech couldn't figure out how to take my credit card. After 30 minutes or so he figured it out and I was on my way, car fired right up and took a 20 minute interstate ride home, in the mid 80* range. No problems.

What is in the engine bay that is so troublesome? My answer lies in the layout of the fuel system. Note where our lines run, right beside the driver's header. If you have exhaust manifolds, you may not even be reading this post. They then ride up all over the hot engine and once again get some super heater header air before heading back to the tank to heat the rest of the fuel supply and consequently, the fuel pump, resulting in cavitation.

I've wrapped half the system, the under hood and tank. No help. Why? I don't really know why it didn't fix the problem, other than with the combo of real hot outside and already hot header, we can't win.

Did This Happen Back In The Day?
For the moment, Id say no. V8 TPIs seem to be the only complainers as of yet. I had a bone stock Z28 TPI car in the mid 90s. Never has ANY issues like this. Took it on many a long cruise during the summer, no problems. Also had a mostly stock (flowmaster) TBI 305 Firebird in the early 90s. Same thing, no problems at all.

Hmm, perhaps upgrading our cars is having some negative effect during the hotter months. Stock pump, stock flowing everything, stock injection, stock manifolds, stock exhaust. Most assuredly, GM would not have manufactured a car that could only run for 9 months at a time in cooler states. This leads me to believe that our modifications may be defeating GMs mass production "safeguards"

The Answer Lies With The LS1
My biggest piece of evidence lies with the LS1 fuel system. A poster (Orr!) recommended that maybe I upgrade to a 4G fuel tank. I researched that for a while and came upon a tidbit that really opened my eyes. The guy said something to the effect that "luckily our cars {LS1s} don't have the return line to heat the fuel supply". Bingo! Orr mentioned his 2001 or so LS1 TA can run all day in the Texas heat. Hence, our return system of fuel injection may be the culprit. Their fuel goes one way: from the tank, into the injector. No hot fuel going in, no hot fuel coming out and contaminating the fuel supply.

That Damned E10!
Is this part of the problem? Offhand, I'd say it is one component of the problem. With so many carburated cars experiencing an upsurge of vapor lock, I'd have to think that the fuel could be hindering our cars as well. Yes, I know there are folks who have this and that and just love the hell out of E10. Good for you, please don't tease the rest of us with how well your car runs! Some of us, myself included, think that the more easily heated (and vaporized) E10 may be a symptom of what's happening as our fuel gets steadily heated along it journey to and fro the tank. LS1s love E10. Again, because their fuel system doesn't hurt E10 like ours does. Stock cars may exhibit no problems with E10 for the reasons I noted above.

If you look at it, those of us who have heavily modified our 3Gs are at the right place and right time for this to occur. Hot summer, hot fuel, problems. Perfect storm really. Does this expose a flaw in the fuel? For the great masses, Id say no. If we all just left our cars alone, I might not be writing this post right now. But who wants to do that? The government (rightfully) is trying to help the environment. Our cars are only a very small percentage of the vehicles out running around and we have exposed a problem with our cars, not necessarily with the fuel. Again, how we fix it may eliminate the piling-on of poor old E10.

How Do We Fix It?
Well....I don't know that either. I suppose someone could wrap the entire fuel system from tank to rail and see if that works. One poster above even ran a fuel cooler to no avail, so I wonder how much effect some heat shielding would do. I don't think the pump-on-a-hanger is the problem. I think the placement of the fuel lines is the issue. That would entail, re-routing the lines under the car, possibly running them through the frame/unibody rails and exiting anywhere not located by the header. That would be quite a chore, however with flex line and AN fittings, perhaps it's doable.
---------------------------------------------

For those of us with weekend warrior cars, we can probably just drive our cars a bit less in the hottest part of the summer and only for short runs. If you own a weekend warrior without A/C in Virgina, then this is just an excuse to leave it in the garage anyway. It's the guys who run them as daily drivers that may be suffering the most. They need to get to work and back. Indeed, if you have a stock 3G, then you may not be having this problem. If you have done the full compliment of bolt-ons, then you may need to perform or come up with a solution similar to what I've described above.

I have emptied my brain of every conclusion I have come up with, right or wrong. Everybody, please weigh in, what do you think?

Chevy86 IROC-Z

iTrader: (17)

Well said. But I'd like to say that my IROC is Bone stock other than the LT1 cam. So my IROC only has the whining FP when the tank gets to about 3/4 empty. Yesterday (Saturday) I drove about 60 miles in the afternoon (10 miles from the 60 where in town cruising) in 108* weather. This was all done on a full tank and I got no FP noise. So givin the fact that I drove a lot of miles in 108* weather boggles my issue in my case. This issue is more illusive as I think Well one thing is for sure. If the fuel lines where wrapped (mainly the return line), then there still is the heat shield. This shield will help prevent the fuel from heating up, but it will still prevent the tank from proper ventilation. I would think that some form of air flow by means of a small cooling fan should be tested to help ventilate the body of the fuel tank should be performed. I would do more but I live in an apartment complex so that severely stops me from doing under the hood repairs or mods.

fatman

If you think that you are vaporizing the fuel due to heat. What we did back in the day with carbs was to add some diesel fuel to the gas tank. I had forgotten about this but a guy that my wife works with has a ranger that showed similar problems documented here. He did the dealership deal with no results then someone running a motorhome remembered this old trick. He added some diesel and the problem disappeared. This is in Kansas with ambient temps above 100 for 30 days. Might try 1/2 gallon with a full tank of gas and see it it helps. This changes the vaporization rate of the gasoline. Try it and see. If you use too much you will start smoking so starting at 1/2 gallon on a full tank might be a good place to start. Or try a quart in a 1/2 tank and see where it ends up. If you feel that you have too much diesel you still have plenty of room for gasoline. Just an old dog trick, I assume no liability, but I have seen it work...

skibum2100

Hello all,

More bad news...I can definitively say the ethanol that is added to our fuel is not the culprit. I was able to get my hands on some colorado gas that wasn't contaminated with ethanol. My car stalled out on ethanol gas yesterday and today the conditions were identical. I thoroughly flushed out the contaminated fuel, added new fuel but my car eventually sputtered and died (after the associated pressure drop). I had high hopes that the "outdated" fuel would keep me running but it didn't help...so I can't point the finger at ethanol anymore.

I hope this helps.

BOSS 357

iTrader: (1)

Sorry Skibum. I took my car out today in 90* and got about 20 minutes in before the pressure started to flux. Got it parked, did my errand and put 1/2 a tank of gas in and that got me home.

I had been talking with Racetronix about their Walbro pump. They referred me to Greg Carroll at Blowerworks (supercharging company); they say he's well versed in TPI cars. He gave me some more things to try. He, Me, TGO, we all agree heat is our problem. I told him my voltages did not drop and he suggested a few things:

-->pinch the rubber return line when the pressure starts to drop:
*if you get a large jump in psi, the regulator may be the culprit
*if you get nothing, he then suggests checking the in-tank rubber hose; said if there a fracture in the rubber, it will open up when it gets hot and your pressure will drop; replace the pump if no fault with the hose is found

He also said the Walbro pumps are a good unit. Also said to get better submersible fuel hose (suggested Gates).

What's odd is that when an issue similar to this occurred in 2007, it was the pulsator that went bad. I removed it and installed a second Walbro with the hose supplied from Edelbrock. These symptoms remind me of the trouble I was having then. I had hoped I wouldn't have to drop the tank, but I think I've arrived at that point now (after the pinch test of course).

Firebat

iTrader: (7)

My car that is having these same issues is a completely-stock V6 car, on its 3rd pump this summer, also with a brand new regulator. However, I know my "rollover valve" on the sending unit is clogged or partially clogged that goes to the ccp.

Fuel injected V6 cars require about or exactly the same amount of pressure as TPI.

Chevy86 IROC-Z

iTrader: (17)

I dont agree. My issue occurs even during the winter at start up, when the tank is about 3/4 empty. So not all situations are heat related.

BOSS 357

iTrader: (1)

Ok, so I sit corrected. MOST of us agree it's a heat issue.

Chevy, are you having the pressure issue or is it just the whine that is annoying you?

Chevy86 IROC-Z

iTrader: (17)

I got a combination of both. When the tank is full, no issues. But when the tank is getting empty, I hear the whine. The whine verifies that I'm running low on fuel (my F. Gauge doesn't work). So when I stop to refuel, as I open the gas cap, the pressure relieves as a whoooosh exits upon opening the cap. So I'm just as baffled as everyone else.

RBob

iTrader: (1)

There should be a heat shield between the tank and the muffler. It may have been removed to fit the previous muffler.

RBob.

z28romance

chevy86, are you sure that your fuel pick up hose isn't cracked?

Chevy86 IROC-Z

iTrader: (17)

Hose? I dont have a hose (rubber) last that I remember. My sending unit is all metal including the lines/tubes. Other than that, when I pulled out my sending unit 3 times within the last 2 years, the unit seeming fine, other than the potentiometer not sending a correct signal to the fuel gauge.

Chevy86 IROC-Z

iTrader: (17)

I just got a reply from an original 91 Camaro owner. This is what he posted to the new thread (related to this thread) that I started...

"mine whined after i raised the fuel pressure too high one day. I lowered it and have had no problems with it for years."

Re: Any "ORIGINAL" 3rd gen owners who still own their 3rd Gens, we need help!

camarosrock1989

iTrader: (1)

Chevy 86> how did you lower pressure? Ok I started smelling gas a few weeks ago, and knew there was a problem. I was working to fix a over heating problem, fixed it with a airdam and front air flow piece.So I hadn't driven to far from home So i decided to take a long cruise to see if over heating problem was fixed, after a hour drive I knew it was. I live in Az and its freaking hot. I started smelling gas real strong about 40 minutes in to drive than stopped at a read light and when it turned green no gas pressure ,started backfiring. Putted to a corner, cracked gas cap, alot of pressure for about ten minutes. Then let it cool and drove back the hour home. Ok I see I am not the only one with the problem. So has anyone figured it out yet. This sucks. Just got the car running real good for long cuises and now this. WTF. So please let me know if you have figured it out. Thanks

RBob

iTrader: (1)

Yes, that is the stock set up. The pulsator, sometimes referred to as the turtle, is stock on the TPI cars. Most folks remove them and replace it with a length of hose. They are known to start leaking.

Stock TBI cars don't use a pulsator, and also use a different pump. It is a turbine pump, unlike the TPI positive displacement pump.

Although the aftermarket specifies the same TPI pump as the replacement for the TBI pump.

RBob.

Chevy86 IROC-Z

iTrader: (17)

I never lowered my FP. The quote is from another member who has an "adjustable FPR". I just copied and pasted what he typed.

darbysan

I had the same problem. Turned out to be a blocked Vent Line to the charcoal canister. The tank is supposed to build up pressure, to 2 PSI. There is a check valve in the line to the charcoal canister that allows pressure in excess of 2 psi to flow to the charcoal canister.

camarosrock1989

iTrader: (1)

D
So did you replace your lines? And did it fix the problem? That sounds like a easy fix. Was just wondering, did your gas get hot? and did you have built up presure? Thanks

darbysan

The rubber line from the charcoal canister to the hard line got pinched. Once I found that, easy fix. Before it was fixed, I had a lot of pressure in the tank- enough to puke out 1/2 gal of gas after driving only 4 miles home after filling up. When I took the cap off to put in gas, it would burp out air for up to 45 seconds. Couldn't believe the pressure that was built up.

Try unplugging the rubber line at the canister and blowing back into the tank, with the cap off. Should be able to blow easily ( don't blow through the check valve).

Joefuss

I'm changine a short part of line tomarrow, the only thing that sucks about replaceing line is they dont sell it anywhere at any auto parts store, im havein to get it made. Theres a orielys that has someone that makes fuel lines, and if hes not there theres another place around here that fabriacts lines, im sure i could find them online but i dont feel like waiting another 2 weeks to fix this problem. I've went to advanced, auto zone, and orielys and apperently not every orielys does this.. i'll keep u guys updated, and please dont let this one die, i want my car to work properly not die out every so often -.- Good luck to all on the fix!!

skibum2100

Okay, good idea...I too have excessive pressure in the tank when my car stalls out. Two days ago the tank got to 121F before the pressure dropped. Today, after tinkering with the charcoal canister and hoses, the tank got to 129F before it stalled. However, the tank still had more than a reasonable amount of pressure built up when if failed.

While working with the charcoal canister I found that it was not easy to blow through the line into the tank so I used compressed air. With air, I could hear the roll-over valve rattling, so it must have freed something up. This valve is supposed to release anything over 1" of pressure, to the canister, according to the FSM. But the ECM doesn't command a purge of the canister until off idle and moving at 15 mph, minimum. So testing by idling in the driveway doesn't allow the charcoal canister to function as it was designed, and may add to our woes of way too much pressure in the tank.

I may try hardwiring the charcoal canister solenoid open, then idling in the driveway again.

Hope this helps.

RBob

iTrader: (1)

It doesn't matter if the CCP is in purge or not. The canister is open to the air. Try blowing into the canister line that comes from the tank. Air should freely move into the canister then vent back out.

This also works when purge is active. It prevents a vacuum from being placed on the vent line to the tank. And pulling fumes directly from the tank.

There is also a tank vent valve that opens a little above what the canister vapor control valve opens at. So if the CCP vent line from the tank clogs the tank will still vent.

1 psi doesn't sound like a lot. But when the tank is near empty that is a lot of fumes.

RBob.

BOSS 357

iTrader: (1)

While I was messing around with the tank vents, I discovered that if you blow into the incoming end of the little round regulator by the canister, it didn't take much pressure at all for it to open and release. My CCP was apparently turned off (as was my EGR) by FastChips a number of years ago. Not sure how it didn't become a problem. Anywho, I used that regulator and put it between the tank and the atmosphere, controls the tank pressure wonderfully.

I'm sure it's apparent to everyone, but I discovered that you can wire up the purge switch manually if you wanted to control it that way. Simple 12v sw, ground, rocker switch.

I'm going to test my FP reg today just to rule it out. If it passes, then the tank is coming down (eventually). My bet is the in-tank rubber line has either degraded or the clamps have loosened up.

John Galt

I never have excessive pressure in the tank when this happens, and it still happens, it happens if I take the gas cap off. I want someone to weigh in on this who knows better than me, because I have only had a third gen for 6 months, and that is also the extent of my fuel injection experience also, everything was carb before. So the question is: Can I put a fuel pressure regulator on the underneath of the car next to the tank? That would stop me from worrying about the engine compartment heat, what ever gas that goes up there never will be coming back, I'll just send the excess right back into the tank right after it comes out of it, and the only heat factor I'll have to worry about would be the muffler under the tank. The only thing I'm wondering is if the FPR being so far away from the injectors would cause any lag when I went WOT all of a sudden? I'm not suggesting, I'm asking. Someone who knows more about this please give me an opinion on this idea. Thanks.

Chevy86 IROC-Z

iTrader: (17)

John, You have a very interesting idea. Not allowing the fuel to reach the point where the fuel lines are so close to the exhaust headers and away from the hot engine compartment is a good idea. But then agian you would have to run a very long vacuum line from the plenum to the rear end where the proposed FPR would be mounted. I never heard or seen a length of plastic vacuum line that is more than 6 inches. Maby a fabricated metal pipe with rubber fittings would be your best bet if you do go your proposed route. It sure sounds very interesting though.