VandykeT/A

Ok I'll start off by saying my fuel pump, fuel filter, relay, cap, rotor, wires, and plugs are new. The injectors have about 60k on them (LS1 injectors). It all started with me driving it about 45 minutes away. It drove there perfectly and just died all of the sudden. I changed the fuel filter in the parking lot of advance and same thing. It would idle but not take fuel at all. You could hold it wide open and it wouldn't go past 2k. You could hear the fuel pump run for the first few seconds of restarting it and then it would stop and the engine would start missing a little more at idle. Well I let it sit about 40 minutes for dad to come to me and then it fired right up and drove 45 minutes back without a problem. Put a fuel pump in it the next day and I've been riding it for a couple weeks. Just short distances though in cold weather. Well today I made it about 45 minutes away and it did the same thing. It would start but woudln't rev up like it was running out of fuel. I could turn it off for a minute or so (it would stay idling) and it would run for 150-200 feet and start cutting out again. I got it to my grandmas and let it sit for 25 minutes or so and I drove it up the road in front of her house without an issue. The fuel pump is kind of loud. Is it possible this is the ignition module? It acts to me as if the fuel pump gets hot and shuts off. You can always here the fuel pump prime and its really loud when it primes but it only stays loud for a few seconds after it starts and shortly after the car starts trying to die or on occasion does die but always fires back up. Sorry for the novel but I'm sick of breaking down on long trips.

BadSS

I had that same problem with mine and was about to carb the thing. I finaly determined it had to be a "wiring" issue and when I finally pulled off the wire looms to run it down,,, I found burned, naked, and pinched wires. I guess the thing had caught fire with the previous owner and he had caught the harness between the engine and transmission - his fix was to put new wire loom around it. I replaced the bad sections of wires and never had another problem with the car.

defaced

iTrader: (6)

Does your car have a MAF sensor?

VandykeT/A

yep its got a maf but I'm not getting a check engine light.

defaced

iTrader: (6)

Well, you may not always get a light. When my MAF went bad the light wasn't on all the time. Took me forever to figure out what the problem was.

Try unplugging the MAF and start the car and see if it will run without it. If it does run, see if it runs any better. There may be a way to check the voltage but I'm not sure how. I figured out mine was bad by unplugging it and noticed that the car ran perfect without it and as soon as I would plug it back in, it would go to ****.

I don't recommend going out and buying one unless you know for sure, since they're like $300 for a stock one.

It was just a suggestion since it seems that you're running out of ideas.

Let me know if I helped.

grasshoppertym

I had the same problem, it would stall out or not resatart after turning off after it got hot. $2 000 and several weeks later the shop finally traced it down to a rusty power wire behind the distributer. it branched to feed power to 3 or 4 different sensors and the after heating up it lost is connection. if i remember correctly they had to remove the dist. to fix it. the wires actully just pulled out of the connector it was so bad.

skibum2100

Next time your car won't start, remove the gas cap and try again. Pressure could be building in the fuel tank...

Hope this helps.

VandykeT/A

See earlier that day I put fuel in it and it hissed for 15 seconds. When I bought it it had a locking gas cap so I bought the one that wasn't locking for the car and it wasn't vented. While it was taking its quitting fit I took the cap completely off. (was just running it loose). Is it possible I overheated the pump from driving it without a vent and from all the repeated starts it couldn't cool down? Several people have told me ignition module does it sound possible?

skibum2100

Sure, ignition modules can misbehave when they get hot, but I didn't know they would kill the motor (thought it just ran like crap?). Do a search to find more info than I can offer...

Unlikely that you overheated the pump by taking the cap off; it is supposed to have a non-vented cap on, but there is a vent under the car for the tank.

The next time this happens try to break down at a gas station when you need gas, fill it up and see if that fixes the problem (cooler gasoline to help the pump...).

Good luck.

chevelle600

iTrader: (9)

My car died one day as I was about to pull into a gas station. It would just turn over and over and not fire. I had already gone through everything in my ignition system over the last 2 years, and I could hear my fuel pump running. The only thing left in the car that was stock was the Ignition Module. Replaced that, and the car fired up on the first crank.

85whtz28

Put a fuel pressure gauge on it and see what it is really doing. Did you change the filter and strainer with the pump? What kind of pump did you buy? Try clamping the return line off with the guage on and see if your pump will build pressure.

I recently went through 3 fuel pumps in about 2 months. I finally got smart and bought a walbro. No issues since then.

VandykeT/A

When we changed it, we changed the strainer and someone had all ready put a new fuel filter on it. Then we changed it again. (original was very shiny). Someone had chanaged the pump before I got the car because the pump we took out thinking was the problem was a Walbro. The one that went back in was a Delphi. The car has 107k miels on it and its definately got the original module in it. It says gm on it and the bolt holes were rusty. Underneath the module there wasn't any grease or anything. I added grease and put it back. But before that I had it tested at autozone and they said it was good. The car only completely died once. And that was while backing up. The rest of the time the car never completely died. It just did everything but. It wouldn't take fuel at all. It would run ok at 1/4 thorttle for about 10 seconds (just long enough to get in the road and up to 40mph) If you gave it alot of fuel it would just smother out. At one point I held it on the floor and it went to about 4k and wouldn't shift out. It had just enough power to maintain a steady speed at 4k. After I got it to my grandmas and sit for about 25 min. It took fuel fine. It still had a some what sluggish feeling when you kicked it but for the most part it was like nothing was wrong. I'm going to change the ignition module and try to get it home tomorrow. I'll let everybody know how the trip home goes. Thanks

VandykeT/A

Also it had been fairly cold the 2 weeks it ran fine. The day it acted up it was pretty warm out. Maybe the warmer weather played a factor to.

defaced

iTrader: (6)

Man, that seriously sounds like a MAF problem. Just do me a favor and unplug the MAF and start the engine and see if she runs. My car did these exact same things when my MAF went bad and took me forever to figure it out because I never thought about it.

If nothing else its at least worth a shot.

VandykeT/A

Update. I put a new module in the car and the pump stayed silent for about 25 minutes of driving and it slowly got louder. It made the 45 minute drive flawlessly. I stopped at dads turned it off and started home I floored it as I left his drive way and the car had no power. then I kicked it again and it started running out of fuel on top end. I took it straight back to dads and left in his car. He started playing with it. And it wouldn't run for more than a few seconds and die. They waited a minute and it started up and ran fine for a few seconds and the same ol thing. They said you could take the fuel cap off and put it back on and it would build crazy amounts of pressure within a few seconds. The pump was extremely loud when I left it. Is it possible the regulator quits working and causes the pump to overwork itself? I'll try to maf thing tomorrow when I try to get it home but whatever it is is causing it to loose fuel pressure. Because it slowly gets worse. At first runs great, then won't pull in high rpms, then midrange, then only idles, then nothing. Everyone is saying bad fuel pump but something is pushing pressure into the tank in a matter of seconds. I've been riding it with the cap loose and they said it built pressure instantly when you put the cap on.

obeymybird

iTrader: (4)

the maf or the maf relay could have went bad either or will cause some of the same issues, if the computer dont know how much air it is taking in it cant add the right amount of fuel.

skibum2100

Check over all your fuel lines for a pinched line.

Disconnect all the fuel lines and breather lines from the fuel tank and under the hood. Blow air through them and make sure there is no blockage (any blockage will make the pump work harder and increase the temperature of the fuel/fuel pump, which will raise the pressure or the pressure can't vent properly).

Good luck.

VandykeT/A

The MAF would cause the fuel pump to be as loud as an alarm clock and force pressure into the tank instantly?

VandykeT/A

Well I hooked a fuel pressure gauge up and idleing I get get 35 with the reg hooked up. Unhooked I get 45. It took about an hour of driving around close to home to get the car to act up. At first the pump is quiet and slowly gets louder. It had a slight hummm to it until I put some gas in it and then I made it back home (mile and a half) and when I pulled in and got out I noticed the pump was extremely loud and I told my uncle who was standing next to me its gonna die in a minute. I then loosened the gas cap and alot of pressure came out and it quit instantly. I put the cap back on and started it and it would idle. It only held 8-10 psi. I played with the regulator vacumm and it had no effect but once it all of the sudeen shot back up to 45 psi a few revs later it dropped right back down. Also when I put the gas in it actually blew the cap out of my hand as i was twisting it from all the pressure. I tried the maf sensor, and ignition module and it made no difference. What do you guys think?

skibum2100

I think you are having a fuel temperature problem...

Probably due to a high flow pump pushing extra fuel through the fuel system (returning a larger amount of heated fuel to the tank). The fuel will normally heat up as it passes through the fuel rail/engine bay, and the metal tank and metal fuel lines are supposed to dissipate the heat. If a "High Flow" pump is installed, the heat that is dissipated is not a sufficient amount to keep the fuel cooled and the stop pressure in the tank from climbing. The fuel gets hot, pressure in the tank climbs, and finally the fuel "cavitates" behind the pump impeller and can NOT be delivered to the fuel rail.

Check out this link...

https://www.thirdgen.org/forums/tpi/...regarding.html

Cheers,
Vince

VandykeT/A

I actually took the line going from the canister towards the back of the car and tried to blow through it (by mouth) and I couldn't I then tried suck back through it and I could feel something trying to come out. Nothing at all should be in the line right? With the cap off I should be able to blow back and forth freely right? Also the little filter thing at the canister would only let air through one way. Thanks Theres no reason to try another fuel pump right? Its just a stock delphi pump from car quest. The previous one was a walbro.

skibum2100

I could not blow through the vapor line either (by mouth) but the air compressor was able to blow through and it created a "gurgling" sound in the tank. I think the lone in-line valve near, but not connected to, the canister is a 1-way valve. Try to blow through just the metal line instead.

Remove the white plastic tank vent (next to the rear brake line bracket on driver-side of the body) and blow/suck through it to verify correct operation.

Eliminate all variables before pulling the tank, then worry about the pump. A CarQuest pump should be ok, but I thought their pumps were made my Airtex (not my favorite company).

Hope this helps.

VandykeT/A

I did blow through it with a air hose. We took it off at the front and the back and blew back and forth. It didn't help. I've tried riding it with the cap off and it still does it. The pump is definately a delphi. I actually work at carquest and we sell both brands lol. I'm lost on this thing.

skibum2100

Measure the temperature of the fuel rail and the outside of the tank when you are having problems, keep the cap on the tank to eliminate variables. I started having problems when it reached ~124F, I have a tranny cooler to cool the fuel before it returns to the tank - not a slolution; only a bandaid. The most likely culprit is the fuel itself, reformulated to boil at a lower temperature-which leads to vapor lock for us.

Make sure your return and supply lines are not bent/kinked/damaged...as any restriction will ultimately increase heat in the system.

Hope this helps.

VandykeT/A

When the car is running fine after about 20 minutes run time the fuel lines are almost as warm as the driveshaft. And is the tank. I don't have a temp gun but they definately get warm. If it were the fuel wouln't every TPI car have the same problem? or anything that used a return line system. My car has gotten pretty religious about dieing. It was about 80 out. I drove my car to town and back twice 15 minutes each way and it was trying to die as I pulled in my driveway on the last trip. I can't drive it anywhere. I'm going to try a new ecm, regulator, and one more fuel pump. After that if it still does it, I'm either selling it or going carb. I appreciate the help.

TOTB_IROC

The vapor canister is clogged I am betting....Same problem I am having but I can't find one for my 87 IROC G series VIN.

VandykeT/A

If it being caused is the problem couldn't you just dremel it apart, seperate it, gut it, and put it back together? What did you do to troubleshoot that it was the problem? Just unhook it and drive it?