VandykeT/A

I have checked pressure when it hasn't been driven and after it starts dieing. I go from 45 unhooked to 35 hooked. When it starts dieing I have 8 psi. It actually bounced from 45 to 8 and back to 45 when its dieing. Never a in between. When it drops to 8 the reg changes nothing. I have had my car die from taking the fuel cap off. But the pump is as loud as an alarm clock when this happens

Firebat

iTrader: (7)

I recently installed a whole new sending unit. I hear no hiss now when I take off the gas cap, even when its 80-90 degrees out. Also have the black valve bypassed that is next to the charcoal canister( just using a hose). The vent thing or rollover valve inside the sending unit and the valve next to the charcoal canister were my issues. No more hiss, no more fuel pump whine like before even at 85 degrees. This summer will be the true test though when it gets to 100. Fuel gauge is off though now, damn you ebay.

Chevy86 IROC-Z

iTrader: (17)

Awake at 3 am? Now that's determination.

TTOP350

iTrader: (8)

I'll ask again, how old and what brand of pump are you using??

panhead201

For some reason it's not showing up here yet,so I'll assume you just assume you just posted iy.Did you say you had 8 psi when it started screwing up? 5(five)? That ain't enough to run a twin cylinder lawnmower.And you said your pump started screaming or making some kind of racket.Ihe bushings around your impeller have got to be worn to nothing or something.Your pump is shot or your filter has collapsed or something.Is it doing this when its cold?If you don't have a kinked line or some other kind of booger between your tank and fuel rail and you've got 5psi your pump is toast.I just happened to hit my e-mail while I've got some welding rods in my wife's oven so
i'll get back to you when i've got time and nobody's yelling at me.panhead201................the more I think about it,It's gotta be electrical. exactly 45 and exactly 8?Sending unit?press reg.?How much pressure is on the primer circuit?I dunno

panhead201

Nah,it's not determination.Since I've been on total disability theres two times.Light and dark.I don't watch TV and late at night it's nice out.A nice breeze when I open up the front and back doors and pretty much AA-hole free.Just me and the dog.Lotta times during the day all I see is pairs of shoes giving me expert advice.One night I set my sweatpants on fire with a torch and my *** was under the gas tank,man it took forever to get outta there,but oh well.Those things burn like they're made out of napalm.I'm thinking about running my fuel lines through a cooler like you can zip tie to your radiator,or they got the kind of tranny coolers that you can attach to your frame rails and I was gonna put the inlet on one side and out on the other.They're cheap and don't weigh anything.I figure ittt's worth a try.panhead201

z28romance

Newer cars have pumps that sit at the bottom of the sump (sock touches the bottom of tank). IIRC we have a pick up hose. the reason they run them like that is to prevent cavitation. By this measure an external high pressure pump would make matters worse. high temps coupled with low pressure between the pick up tube and the pump impeller. the impeller is where the cavitation bubble forms. this is the point where the pump is sucking on a gas.

Its possible modifying the sender to lower the pump to the bottom of the sump would help.

Also a remote FPR would help, keeping the return fuel away from the engine bay would help tremendously.

Chevy86 IROC-Z

iTrader: (17)

There is no pick up tune and the pump does sit towards the bottom of the tank. There are many posts on this particular thread that a few members have dropped the tank more than 2 times within a few months. Might I add, I had to drop my tank 3 times in 4 months, but for other reasons. So that's how I know that there is no pick-up tube.

nomad350Z

Suppose this is as good a time as any to throw in my two cents....

I've been following this thread since its inception, and have had these issues every since I moved to New Mexico. After going through three Walbro 255's (two of them were 0169's), I finally opted to get a Delphi EP381 for a Turbo Trans Am/ Syclone pickup. Pump lasted longer than the Walbro's, but still would whine and die.

After reading Firebat's post (#552), I decided to run a test on my charcoal canister. I thought it ridiculous, how could my charcoal canister affect fuel pressure?

But, I tested it, and it failed miserably. So I removed it, ran the inlet to the canister from the tank directly to the outlet from the canister, bypassing the valve. At the same time, I used compressed air to blow out all the fuel lines, even blowing out all 4 lines back into the tank (to loosen the checkvalve).

Its been two days, no problems yet. Even on a low tank, riding around for a few hours, and going around turns - no whine. Will keep you all posted if it resurfaces.

Chevy86 IROC-Z

iTrader: (17)

/\ looks like your on to something. Interested to find out your results.

kooga

Got som issues with my car too Iroc-89. After an hour drive , parked the car and noticed bubbling sound from the canister , opened the fuel cap and let out the pressure , lots of it , waited 3-4 minutes and opened the fuel cap again , same thing , after 20 minutes still some pressure. Last year when driving for long trips and stopping you could hear humming sound from the rear and if I dont recall wrong it wasnt overpressure in the tank but vacuum . Something definately has changed . Checked the pressure valve next to the canister and the top where the small vacuumline attaches was full of fuel , pour the gasoline out and checked it with a vacuumdevice and it checked ok . Checked the little pressure-vacuum thingy next to the tank and it looked ok , the valve opened up both in and out . Got a nonvented fuelcap . Testing the canister according to the shop manual , but here is where I got confused , the manual says to try to blow throw the lower pipe and little or no air should pass , i could blow like there was no resistans ? Next test says to apply vacuum to the upper pipe and it supposed to hold vacuum for 20 sec , and it did , but thats the pipe for the solenoid and its not opened without ecm signal . Then the manual says to try blowing throw the lower pipe and ofcourse its no resistans again . The canister is a rochester 17088067 LF . Checking the canistersolenoid and it works ok , no leaks and opens when the ecm energizes .Vacuumhose to the canister ok . Is there supposed to be a diaphragm in this kind of a rochestercanister ? Ive searched but havent been able to find an answer . It looks like this acdelco and has no filter you can change , http://www.amazon.com/gp/product/B00...=ATVPDKIKX0DER
It wasnt a warm day when I drove , but the overpressure still there . Could it be the fuelpump overheating causing this , not sure if it has been replaced . Was below half tank left .
Living in Sweden and parts isnt growing on trees here :-( . So before i order new parts I tend to check everything .
Anybody got a rochester or similar canister that could blow throw the lower pipe and check or knows whats the deal here ? Dont wanna cut the canister open but the thought occured to me :-) By the way no fuel in the canister when i checked . The pipes from the both the valves is also ok no restrictions .

RBob

iTrader: (1)

From your descriptions it sounds like the canister is OK, but the vapor control valve is bad.

On the canister, the upper port is blocked by the closed solenoid (note that some solenoids are normally open and close via ECM control). The lower port on the solenoid goes into the canister, this port connects to the TB.

The lone port on the canister is left open to the air. So the path of no resistance from the lower solenoid port is into the canister then out the vent port. The canister never has any pressure in it. The vent port allows fumes to enter the canister from the fuel tank. And air to enter the canister when being purged.

The vapor control valve is also a pressure regulator. It won't open until there is about 1 psi of pressure in the fuel tank. At which time it opens to vent the fumes into the canister. The small port on it is just a vent, and should never have fuel or even fumes at it. It should also hold vacuum when testing it.

The other two ports on the control valve, should pass pressure (need enough to open it) from the tank side through to the canister side. And in reverse, should not pass any pressure. Can use vacuum to test via a hand pump.

Note that this is for the (about) '87 through '92 MY f-bodys. The earlier ones and the 2.8l engines use a different set up.

RBob.

kooga

Thanks for the reply , makes sense to me now :-)
If the vapor control valve stays shut , and the ecm opens the solenoid , there will only be air drawn from the canister , but is that enough air to create a lean condition ? Have troublecode 44 sometimes and the blm-s goes up to 160 , and the o2 sensor is below 0,2v , not swinging . this happens at highwayspeed say over 60mph .

//Christer

88IROConv

To add some information about my situation. My car is all original except the battery and serpentine belt with 19,000 miles. I noticed pressure in the tank during the summer of 1991 with 9,200 miles on the clock. It got to the point where I could no longer fill the car up with gas when the engine was hot. As soon as the pump clicked off and you pulled it out gas would come shooting out. I could hear the gas bubbling in the tank. This never affected the performance of the car until the summer of 2002. That's when it developed an off idle hesitation which was totally random. I could never figure it out for years and years. Just this past weekend I accidently discovered the temporary solution. I got tired of pressure building in the tank so I decided to drive around with the gas cap loose. When I stopped at lights I could smell gas. I thought I had a fuel leak but then I got to thinking maybe it was vapors from the filler neck. I pulled over and went back to the filler neck and sure enough I got a good dose to fuel smell. So I tightened the cap back up and drove off. Immediately I got the hesitation back. I was thinking there is no way the gas cap has anything to do with the hesitation. So I pulled over again and loosened it. Car ran perfect all the way home and runs fine as long as I leave the cap loose. So now I have the same question you guys do, what's causing the fuel to boil. I'd be curious to know since I had the problem in 1991 if GM was aware of it.

bungo78

iTrader: (1)

I'm Back!!!

Who knew my issue would have spawned to such a response!

I've currently solved one issue @ a time. I've replace the ignition module, dizzy, etc... It does not "die" any longer. However, that was just one step to the solution i am still hunting.

The fuel pump still whines and the longer I drive the stronger(pronounced) it get's. a couple months back it was pretty warm out here and I was driving for quite sometime. When I turned it off, I actually heard boiling in the tank!

I'm replacing the pump next and using the suggestions below from RBob to touch on everything that I can.


I have been reading along as everyone has posted. Whether you have a similar problem or have been chiming in to offer help. I thank you all for your participation.

A....

RBob

iTrader: (1)

Once the canister is clean the BLM will go up a little. But not to 160 as you are seeing. That could be caused by a bad MAF or fuel pump.

RBob.

80schild

iTrader: (5)

I don't know if it's related, but does anyone else notice their canister solenoid gets really hot? Mine gets hot enough to burn my fingers.

VandykeT/A

Well, I'm pretty sure my problem is solved (knock on wood). My car got to where within 25 minutes of run time my car would start sputtering. Well today I decided since I'm gonna be swapping pumps alot more than likely I would cut the trap door (I know) but I installed my 2nd delphi pump (90 something bucks at carquest) and a new spectre sending unit. I've drove the car for around 3 hours today all basically at once and I haven't heard the first noise from the pump even with the trap door not shut. I honestly believe I have fixed my problem unless something is actually burning the pumps up and only time will tell. It was around 70 today.

Speed Racer X

Add me to the list. 89 Form 350 Vho, supercharged, everything else stock, 30000 miles.

Runs like a champ then just shuts off. First I thought it was from heat on a 90 degree day last weekend but then it happened just a few minutes after startup yesterday on a 80 degree day.

New fuel pressure gauge shows a hair over 40 keyed and a hair over 35 running.

Chasing pump, fpr, charc cannister, etc to find the gremlin.

I did notice lots of pressure when releasing the gas cap.

I can hear the fuel pump working when the cap is off and I listen but I don't get any weird sounds from it. Pretty sure it's the original fuel pump.

kooga

One thing that comes to mind is , the fuel gauge . When I drove around and braked and accelerated the needle was all over the place , dipping low down when breaking etc , not like before this issue started , pretty stable. I guess that if the pump cavitates , the bubbles will cause some kind of bermuda triangle in the tank , making the floating device not floating so good anymore :-) I have ordered a reman ecm , a new vapor control valve and a Racetronix fuel pump with the hotwire kit . I have already missed a couple of musclecarmeetings because of this , and the summer is short here so I really hope this will fix the problem .

//Christer

Chevy86 IROC-Z

iTrader: (17)

The reason why your fuel gauge needle goes low when breaking is because when you brake, the fuel inside the tank moves forward. The floater is towards the rear of the tank. WHen you accelerate, the fuel moves to the rear of the tank in which the floater moves up according to the raising fuel level. So no Bermuda Traingle in your tank. Just inertia.

kooga

Well , Ive seen the movement of the fuelneedle earlier too , just that lately it seems the go further up and down , or maybe its just me imagening it .

//Christer

camarosrock1989

iTrader: (1)

I bought 3 window shades and lined them in the hatch area, thinking to reflect some heat. But not sure that its helping.

Chevy86 IROC-Z

iTrader: (17)

Well between the tank an the inside cargo sheet metal, there is about .5" to 1" air space. I'm not too sure how much a hot trunk deck would affect the temp of the fuel in the tank, not to mention the airspace between the fuel level and the roof of the inner tank. But I could be wrong.

87350IROC

iTrader: (2)

The heat is not coming from sun through the rear hatch. There are way to many layers there to get to the gas. I have dark tint all around and still have this issue.

SilverLT1vert

I've read this thread from start to finish because I believe I'm in the beginning stages of having this issue. To begin, I do have a little history with this problem. I helped my brother replace his fuel pump on his bone stock 91Z28 convertible about seven years ago because his fuel pump was cutting out when it was hot out and he drove around for a few hours. About a year after replacing the pump (basic autozone replacement pump) he started having the same issue again, but he is super lazy and rarely drives the car long distance so he's not too worried about it (60k original miles and it's beautiful!)

I just finished partially restoring my Iroc, so my brother and I took our cars to the F-body gathering in Atlanta this past memorial day weekend. Of course his car died a few times on the way down because it was hot as crap! Putting in fresh fuel fixed it every time and we could continue another hour or two down the road. Of course my car did perfectly fine under all the same conditions. I only have a small cam, full exhaust, and a hypertech chip for engine mods. When I bought the car it had a bad fuel pump from sitting, so I carefully cut open the hatch floor to access the FP and installed a new Walbro 255 and adjustable FPR.

Well, since I just finished getting the car back together I've been driving it like crazy! I have a little over 1k miles on the pump, cam, etc, and it runs awesome, until the other day. I had just under 1/4 tank, maybe closer to 1/8th (only my fourth tank of gas in the car) and I was taking a long gentile curving on-ramp while accelerating to get on the highway and the car stumbled for a second then regained power. I didn't think it was a problem, just fuel sloshing in the tank (I know it's not baffled like the 1le). Well I get 20 miles down the road, and the car really started sputtering and had almost no power. I didn't really know the gauge that well so I'm pretty sure I was about to run out of gas, so I just kept cruising at like 35mph in 65. Incredibly I made it to the gas station, filled up, and the car was fine. Then I just recently went on a 45min trip and right before I arrived at my destination, my car began to lose power slightly, but it was barely noticeable. When I stopped, I could hear the pump about 3 times more loud than normal. So I shut it down. The next day, I drove 45 min home and it started to lose power and the pump was whining like hell when I pulled into my garage. I still had over 1/2 tank!

Does anyone think this is related to me allowing the pump to briefly run dry just so I wouldn't need a tow? My pump isn't one of the recalled units either. Also, I left the pulsator on the feed line when I installed the pump. I honestly didn't know you where supposed to take it off! I have the trap door mod, so I can easily pop it out to see if that helps. Also, I found photos from when I installed the pump and it didn't have the disc between the sock and pump, and I didn't install the sock under the return line either. I think I might try diverting the return flow away from the pickup anyway just to see if that helps. The theory that the hot pressurized fuel would boil instantly as it exits the return tube into lower pressure tank allowing bubbles to be sucked into the pump makes sense to me!

Also, my '97 LT1 Camaro has almost 100k and has never had any fuel related issues and it is return style like the third gens. I looked up photos of the LT1 style sending unit and the pump sits in a bucket that holds fuel to keep the pump submerged and cool. The return line dumps into the top of the bucket instead of just next to the pickup like on the third gens. The cars are so similar, it just makes me think there must be a way to adapt this "bucket" system to our cars to prevent fuel starvation and overheating issues, which have never happened to my LT1. Or maybe there is a way to fabricate a new "bucket" to fit the third gen pump assembly?

And I don't want to hear anything about the charcoal canister, because absolutely everything emissions related has been deleted off my car, as well as AC. It's not a tank pressure issue because it's vented to open air.

TTOP350

iTrader: (8)

I have ran a 200,000 mile Grand Am fuel pump dry for 30 mins and it didnt die.
I ran a few stockers that have died in less than 1min of being dry.
Id say its the luck of the draw.. sounds like you need new pumps. I would also put in the Racetronics Hot wire kit. Fuel pumps/electric motors die more because of low volts than running dry than having to much voltage.
Stay away from cheapy pumps unless you want to use their warranty often!

If your car is a 85, go to the junkyard and grab a rustfree tank/sending unit from a 91-2 f-car. Its a 1LE tank. ;-)

camarosrock1989

iTrader: (1)

It actually has helped some! I have not stalled yet and we are at 105 deg here in Az
I am going to work on my charcoal canister also. One amazing thing i have got charged is my AC! Cold as ice Wow it is so awesome to have a cold AC! I do have a noise though coming from compressor sometimes now. If not one thing its another..

VandykeT/A

Update, after replacing my fuel pump again, PO had a walbro, I put in a delphi, then a 2nd delphi with a new spectre sending unit, its fixed. I've rode it in 95 degree weather for over 4 hours straight and not a single problem. I also have headers and the line is practically touching the header tube. I've had to have put at least 1k miles on it. I ride it to work everyday now. I still have pressure in the tank but no noise or sputtering and dieing.

SilverLT1vert

I agree that not all pumps are equal, but I do not believe that mine should have died with about 1k miles on it, and only run dry once! Also, I know for a fact that mine is not a voltage issue. I relocated my battery to the trunk with 1awg power and ground. 4awg alternator charge wire, and two massive audio cable 4 awg engine grounds. Also, I rebuilt my alternator and it charges consistent 14.5V with the engine, fan, blower motor, headlights, interior lights, and stereo with amp on. I've tested the voltage for drops throughout the entire system (wanted to make myself 110% sure all my grounds were good) and didn't have more than 1/100th Volt loss through any wire. So unless the hot wire kit comes with a transformer, I would be hard pressed to send any more current or voltage to the pump than it's currently getting.

So here's my theory and plan of attack on this situation. First I'm going to remove the pulsator (per members' recommendations) and fabricate a diverter below the return line to redirect hot fuel away from the sock. Also, I will install a new filter sock while I'm in there. If this doesn't fix it, or only has marginal results, I will modify my sending unit to accept the LT1 style bucket, sock and return line that feeds the top of the bucket. The reason I want to try this is because I've never heard of a single LT1 or LS1 having this issue, and the cars are VERY similar. Why is it that stopping to top off the tank fixes this issue for EVERYONE, EVERY TIME?? Because, on LT1 cars the pump is always submerged in fuel, keeping it cooler and lubricated. AND, it never gets a chance to run dry, even in hard corners. Very simple solution to a very simple problem. Third gens are inferior to fourth gens in almost every possible way (except styling of course , so why would this be any different? I'd like to know if anyone who swapped in a fourth gen tank has had this issue? I'm not saying I'll tackle this problem tomorrow, but it will be soon and I'll report back with my findings.

TTOP350

iTrader: (8)

I had a nice lil reply for this but my computer all of a sudden put its helemt on... I'll try again

Outstanding job on your rewire of the car. I did mine with 00 finestrand welding cable from the rear to the front. Power goes to starter and ground goes to the belhousing bolt/stud. The factory cables are routed to the fake batt and I have my MSD inside the batt. I can jumpstart my car from the org batt location.
Did you rewire the electrical system on your fuel pump or is it all stock wiring still?? The hot wire kit uses bigger wire for your pump and it does help..

The fuel pump sending unit return line on a 3rdgen dumps on the sock to help keep your pump from going completely dry in a corner with low fuel levels. (its kind of a crutch)
3rdgen 1LE/ 91-2 tanks are the same but have a baffle to help control fuel slosh/starvation.(get this tank)
(Y didn't the 3rdgen cars have fuel heat soak problems when new?????? my bet on this problem is bad replacement pumps, improper tank PSIs due to blockage/ in op charcoal canisters and or weak electrical)

LT1 tanks have a similar setup but the return dumps into the pump canister.
My friend is having fuel pump issues in his 20,000k mile 95 Hawk. The stock one petered out at 15k and this walbro 255 was put in by me and it was having issues already at 1,000 miles after the install. I think it was from the bad batch tho. still guna pull the tank out to fix it again.

LS has a regulated intank return line that dumps into the canister and helps keep return line fuel heat low. There is a early steel LS tank and a later plastic tank.

I put the 1st ever delco fuel pump in my my moms 91 cutalss at 280,000k miles. It was noisy and lasted 1,500 miles. I put in the 2nd delco pump and its still going at 400,000k miles. just luck of the draw.
Even if they are new they can peter out. (all brands)

diy_zman

The last time I drove my IROC ( LB9 ) it did the same thing as most of what this thread is about, It has been doing it since I bought the car over 2 yrs ago. When I left the house I noticed that I only had a little over 1/4 of a tank of gas, more than enough gas for the little bit of running around I was going to do and it was in low 90's that day. Was heading home and it quit about a mile outside of town. Usually I let it sit for 30 - 40 minutes and it starts right up and takes me home. But that day it seemed to be taking longer, in one of my attempts to start it up again I noticed my gas gauge showed I had absolutely no fuel what so ever. I thought this was very strange as I only put about 12 - 15 miles on the car and that shouldn't have used up a 1/4 of a tank. So I called the wife to have her bring lawn mower gas can as I knew it had about a gallon or so of gas in it. So I put the gas in and tried it and sure enough it started right up, but the weird thing about it was that now the gas gauge was back up almost exactly where it was when I left the house. Anyone else ever notice their gas gauge doing this? Not sure why it did this or if it even has anything to do with the problem, just a thought . .

Chevy86 IROC-Z

iTrader: (17)

There's probably a bad spot on the travel range of the potentiometer looking thing.

mikebondi

ill throw my car in this aswell

my set up is radically different from the cars that are in this thread.

i have a 91 rs with a lq9 bored to 408 ls engnine ls6 intake and a 255 lph walbro pump
aeromotive fuel pressure regulator and a fuel rail mounted fuel pressure guage

mine started a few weeks back shut off on highway. it was hot out car was hot and the thing shut off on the highway at 75 mph. i let it sit and if fired right back up. drove about 8 miles and it shut down again. that time i forgot i had a fuel pressure guage under the hood.

got my fans fixed today and was driving home it was about a 35 mile round trip and it was about 90 or so out maybe a bit hotter it shut off again about a block from my office. this time checked fuel pressure and it was at 20 psi. it started up fine at 20psi but would not run and died again. let it sit about 20 minutes and pressure went back to 55 and it made it to my office no issue.

while i was at the shop my car was scanned on a scanner and only code was one about my clutch position switch.

between these two times i ran about 9 1/4 mile runs with no issue. i dont drive the car much mainly just to the track down the track and home.

looking at redoing my pump with a fresh walro 255 and a racetronix hotwire kit. has anyone seen success with this.

mikebondi

has anyone tried swapping to a 4th gen fuel tank. like a 2001 ls1 plastic tank. i see one of the advantages is that it has the bucket to keep the pump cool.

Chevy86 IROC-Z

iTrader: (17)

Let me ask a buddy of mine. I think he installed a forth gen tank. I'll have an answer later on tonight.

87350IROC

iTrader: (2)

How close are the fuel lines to exhaust/headers? Heat shield between muffler and gas tank?

ThunderODB

I had to skip to the last couple of pages to see if anyone actually found a CURE for this and not just a bandaid, so I apologize now if this has already been covered.....

Has anyone considered that it is not the pump but perhaps the FPR that is causing this issue? Clearly the problem is heat related, so maybe the fuel being pumped to the engine, heated, returned to the tank over and over is having a cumulative affect on the FPR and causing the diaphraghm to get weaker and weaker, eventually causing it to stop regulating altogether?

Just so I dont get called a troll........yes, I am having this problem too...and my car is almost completely original, with the exception of the entire ignition system (new dizzy, coil, module, wires, plugs, OEM, but brand new) and the fuel pump which has less than 500 miles on it.

I have seen some of you criticize the Autozone (airtex) pumps, however, it seems very unlikely that Autozone would continue to carry a product if they have a lot of issues with it. I am of the opinion that heat is to blame in some form, hopefully someone discovers the remedy for ths, I would really like to go drive my vert on the weekends and not have to worry about trailering it home. I have had this car for a year and so far have hauled it way more than I have gotten to drive it.

mikebondi

my exhaust exits before rear wheels. so i have no exhaust near the fuel tank. have not looked at the lines to check where the fuel lines run in relation to the exhaust. i will look at that tonight. its driving me pretty much crazy. i made 4 time trial runs in 103 heat sunday and it died in the staging lanes for the 1st round 1st class. car is not overheating. even in 103 heat never broke 205. between runs i put in in the shade of a tent and opened the hood to cool the engine. this is the quickest it has done this yet. oh yeah i ran it with a ton of fuel started the day with 3/4 of a tank to try to keep the fuel cool. as it sits its just below a half tank right now.

Chevy86 IROC-Z

iTrader: (17)

I just had to throw this out there. According to my GM Mechanics Service Manual, the fuel rail was designed to cool off the fuel. Go figure. lol

Chevy86 IROC-Z

iTrader: (17)

There you go everybody,,, a RS that has the same issue. So its not only a TPI issue.

ThunderODB

But it is still EFI, not TB and not carbed The fact that it is an RS is irrelevant. Unless you are talking about someone that is running some sort of modded tank setup i.e. a 4th gen tank with the bucket style pickup or a racing fuel cell.... the fuel tanks are the same, the in-tank hardware is the same etc....... unless, of course, it has a 1LE tank, then its baffled, like all of us........

TTOP350

iTrader: (8)

Its also a 6.0 LS swap.

To a poster ThunderODB, yes airtex is that bad of a pump.
I'm surprised Autozone is still open.
If I were you, and you haven't, I would try a racetronix walbro 255 pump with a hot wire kit.

These cars didn't have this problem when new.

My car has a walbro setup with hot wire kit. The LTheaders have a 3" pipe that runs 1" away right under the fuel feed/return lines on the dr side frame rail for around 2ft of length.
My car doesn't die because of "heat", it has 240,000 miles on it and I drive it great distances..

Chevy86 IROC-Z

iTrader: (17)

Isn't TB EFI?

mikebondi

well i believe my first step is to go to a racetronix "walbro" 255 high pressure pump with the hotwire kit. this will cover the pump as well as the relay in one install.

the current pump is a jegs 255 lph tpi pump. not a walbro as i previously thought/was told/ maybe heard what i wanted lol.

if that doesnt work i will be game to try the pressure regulator. i talked with a fuel system guy today. he also questioned the location and type of regulator i have on the car.

ThunderODB

Point taken.

I think im just going to order the racetronix kit as well. I dont realy want to take the tank back out, but what have I got to lose at this point, other than the 150 bucks and a couple hours of my time.

The car hadnt run for 7 years when I brought it home, so I guess I should be happy this is the only major Gremlin.

mikebondi

all this talk of hot wire kits from the alternator and just a touch less power makes such a difference.

im just throwing a shot in the dark. could the alternator not be running as efficient in the heat and dropping the voltage supplied to the fuel pump. there is no doubt it gets way hot under my hood with the heat and the engine running my voltage guage is inaccurate to put it nicely. it bounces more than my fuel guage does. im guessing its been covered in the thread so far but i didnt see it in my hours or reading.

TTOP350

iTrader: (8)

The wires going to the fuel pump are very small and 20yrs old.
Wait till you see the diff in the wire sizes in the Hotwire kit. It supplys the pump with the full alt output all the time.

LilSki

iTrader: (1)

You know you might be onto something about the wire kit/alternator. I ran a 60 amp alternator (original carb alt) last year with dual fans and had the loud pump issue. This year I put a 100 amp alternator and it was 95+ for 3 days last week and the pump never got loud. Other than the engine nothing else has changed in the fuel system from last year.

TTOP350

iTrader: (8)

low voltage/amps is harder on a electric motor than over volts/amps..