Truck Help

[Anonymous-0]

I know this is for tractors, but there is
much knowledge here, so here is my question.
I have a 2000 Chevrolet with 5.7 liter. It
sometimes does'nt start. It tries to start, but
dies. Let it set awhile and it will start and
run fine. It did this a few months back and never
did it again until the other day. It is not heat
related because it does it if engine is cold or hot. Mechanic wants to put in new fuel pump, but
I think it is something else. There is no check
engine light and no codes in the computer.
Any of you had this problem before? I can
give more info if needed. I appreciate any
ideals.
Thanks to all.

 

[Brian in MO]

Russell, I have a 96 chevy (350 vortec) it did that and would crank alot of times before starting when it did start, it ran great after it started. I finally changed the fuel pump (like several people told me) not really thinking that was the problem, and it starts great now. I know there's alot of difference between my truck and yours but the problem sound about the same. Brian

 

[Leon R]

Don't just change the fuel pump without first checking to see if it is putting out the right pressure. Your mechanic should do that before just replacing the pump.

 

[buickanddeere]

Get a fuel pressure test gauge and thread it onto the test port instead of guessing.
Summit Racing has some heavy Duty Bosch units that might be better quality than a AC Delco?

 

[Gene Davis (Ga.)]

I have a 97 GMC 5.7 and it did the same thing. I ignored it till it left me in the parking lot at the grocery store for need of a fuel pump replacement. They are sometimes erratic about starting when they are going bad.

 

[omahagreg]

I have a 96 Chevy 1/2 ton with the 5.7, and it was doing that too. Mine has 2 battery cables to the positive side of the battery. The closest one to the battery was not making contact, and fed the relays on the fender well, under the hood. That is where the fuel pump relay is powered. Changed out the cable, and now have not one bit of problem. Greg

 

[Anonymous-0]

I'd check the fuel pump pressure first ... has to have 60-66 lbs or it won't start. I'd check/replace the fuel filter before you do the pump... it's lot cheaper and can give you the same symptoms. Bruce in NE Indiana

 

[Anonymous-0]

We have a GMC 1997 5.7 and it was doing the same thing. Sometimes it would start and sometimes it wouldn't and it ended up being the fuel pump every time you wanted to get it going you would just kick the fuel tank until it started but then one day it quit on the side of the road and that was the end of that fuel pump, no kicking this time

 

[KEB]

Agree its most likely the fuel pump. Had a chevy van do the same thing some years ago. Befor the engine is running, the computer assumes the pressure at the fuel rail is where its supposed to be and controls how much fuel it injects by opening the injectors for a set period of time. If pressure is low, there isn't enough fuel delivered through the injectors to start the engine. Once the engin starts, the computer adjusts the length of time the injectors are open based on RPM and throttle position, and can compensate somewhat for a weak pump.

There's a schrader valve on the fuel rail that you can connect a guage to. The manual should tell you what pressure there should be with the engine not running.

The fact that it tries to start would indicate that there's some fuel, so its probably not an electrical problem. Some Chevy's also have a pressure damper on top of the pump that can also fail, but if I had to go to the trouble to drop the tank I'd replace everything in there.

Keith

 

[Leland]

mine done that but turning the key on and off about 4-5 times would build enough pressure to start it but that pump was a costly litte buger to have replaced

 

[Pitch]

GM has some lousy pumps Good for abour 60,000 miles. I think that I have replaced one in every gm I have owned in the last 20 years.

 

[Anonymous-0]

Rap on the bottom of the tank a few times with a rawhide or rubber mallet. Works everytime when we have to get one in the shop with a bad fuel pump
Ben

 

[Anonymous-0]

In my experience; FUEL PUMP

 

[Anonymous-0]

Friend has a 99 Tahoe 5.7 that did something similar. Worked fine for weeks at a time, then suddenly would start and quit right away. Come back an hour later, fired right up and drove away.

Turns out the chip key was bad and telling the computer that someone was trying to drive off without the proper programmed key. New key with proper re-program and no problems.

Just another idea...

 

[Anonymous-0]

You should be able to hear the fuel pump run before you crank the engine.Put a pressure gauge on engine test port before you replace the pump.Replace the fuel filter first.