2000 5.7 3500 Chevy Express Stalling

[IndianaJ0nes]

Maybe someone will be familiar with this scenario. This van had a stalling problem after putting in all new main electrical lines, alternator, starter, battery, grounds it started to stall a lot less. There was a lot of corrosion. Then I worked it down to the fuel pump relay which was getting hot. I changed it and the van went a good 50 miles before stalling again. So I put another relay in and it went about 84 more miles to Rapid City. I decided to crawl under the van and found the fuel pump connector covered in power steering fluid. I changed both high pressure hoses to stop the leak(that was fun) and thoroughly cleaned the connector to the fuel pump. This was 8 weeks ago, in more than 1000 miles I drove up to North Dakota and Minnesota working for a while then left , to South Dakota and came back to Colorado, not a problem since. Until today climbing a hill on BLM land on the western slope it starts stalling again. I get under the van the connector is dry, i spray it down again, still stalling. There are no codes or check engine lights, as it dies it says check gauges then the battery light comes on. Yet the gauges are sitting at textbook level.A few seconds later I can restart it. I am stumped.

 

[bullfrog]

The battery light is simply telling you the alternator has stoped charging which is a normal indication when the engine stops running. There is no indicator to tell you the fuel pump has lost power but that sounds like that is what is happening. Most likely corrosion has gotten in the plug the fuel pump relay plugs into and is causing excessive resistance heating up the coil in the relay causing it to fail cutting off the power to the fuel pump. You can test this theory out by using a fused jumper wire set to the pump side of the wiring harness plug that goes to the pump and see if that temporarily fixes the problem. Be sure to disconnect the wires after you turn off the vehicle. If you have a relay that has a picture of the terminals on the case or a wiring diagram you can remove the relay and make a simple jumper out of a short piece of wire with a male spade terminal on either end and insert them into the contact terminals(power in/power out to the fuel pump) where the relay plugs in. Again you will have to remove it when you turn off the vehicle or the pump will continue to run. You may have to clean or replace the plug in and some of the wiring if you cannot cleanup the corrosion.

 

[bullfrog]

The power steering fluid shouldn’t have any affect on the plug other than maybe when you cleaned the plug it made a better connection, sometimes just wiggling a corroded wire will make it conduct electricity better.

 

[Sofisintown]

If you have a relay that has a picture of the terminals on the case or a wiring diagram you can remove the relay and make a simple jumper out of a short piece of wire with a male spade terminal on either end and insert them into the contact terminals(power in/power out to the fuel pump) where the relay plugs in.

I thing the computer is gonna have a fit if he does that.
Car computers are known to go berserk for far less than that... :-/

 

[B and C]

When is the last time you replaced the fuel filter?

 

[highdesertranger]

you know we are all just guessing here.

how many miles are on this van?
when was the last time the fuel filter was replaced like Brian asked?
you didn't notice the power steering leak before?
next time it stalls check for voltage at the fuel pump. if it has voltage check to see if it's working(pumping fuel).

highdesertranger

 

[bullfrog]

The one thing that bothers me when considering the computer is I believe there is a sensor that senses a high load on the power steering pump that may go bad and cause the car to stall, but I believe it should cause a check engine light and it is really rare to have that happen. Yes the reason I suggested a jumper to the plug underneath the vehicle going directly to the pump first is it shouldn’t affect the computer. A wiring diagram will show you if it can be done at the relay plug in and which terminals to jump.

 

[bullfrog]

Intermittent problems make it difficult to trouble shoot fuel problems. You would think manufacturers would offer a fuel pressure gauge as standard equipment.

 

[bullfrog]

Yea I don’t play the lottery and this type guessing doesn’t cost me anything but as I get older my crystal ball is beginning to fog up! By putting 12 volts directly to the pump you pretty well rule out any electrical problems other than a bad pump. The next step for me is if the pump is running is to remove the filter and install my fuel pressure gauge. If that checks good I replace the fuel filter and start looking for problems else where.

 

[VanFan]

Just my two cents, but there is an "idle relearn" reset sequence that needs to be done when a battery is disconnected.  I don't know whether this applies to your year model, but it definitely does to the '96 5.7L.  It's free, takes under a minute, iand is worth looking into, IMO.

I used to have a battery disconnect switch on my Express to deal with a parasitic draw (have since swatted that bug).  The van would stall when idling after warming up, which was unnerving and potentially very dangerous (one good power brake; one good power steer--you know the feeling).  Stepping through "idle relearn" cured that issue.

Also, I agree that the 5.7L is especially sensitive to fuel pressure, and the filter is a good place to start.

 

[IndianaJ0nes]

@ Bullfrog Yeah that was what I was assuming about the batt light. Took the main fuse panel out and opened it up all the blades are silver and the wires to the fuses and relays look like new copper. So i did not run a jumper but drove into town and bought a fuel pump for $200. No problems with stalling today. Guess I will put a hole in the floor in the next couple of days...
[/quote]

 

[IndianaJ0nes]

When is the last time you replaced the fuel filter?

about 3 months ago.

 

[IndianaJ0nes]

you know we are all just guessing here.

how many miles are on this van?
when was the last time the fuel filter was replaced like Brian asked?
you didn't notice the power steering leak before?
next time it stalls check for voltage at the fuel pump.  if it has voltage check to see if it's working(pumping fuel).

highdesertranger

Yeah guessing is about all I have next. I have hit about everything suggested  the dealership mechanics suggested short of changing pump, some have said it might be the pump being nice and warning me its about to crap out and not leave me stranded like most pump failures. One thing I know the corrosion on the main wires destroyed all the main electrical parts on the van so I wouldn't be surprised if this is also a soon to be casualty. Glad I like to wrench...
309,000 I've put 9000 on it was a fleet van. New motor ect
fuel filter about 3 months ago
Yeah I did but did not think it was that bad,
I am tempted to hold off on installing the new pump and check for voltage when it starts to stall again.

 

[IndianaJ0nes]

Just my two cents, but there is an "idle relearn" reset sequence that needs to be done when a battery is disconnected.  I don't know whether this applies to your year model, but it definitely does to the '96 5.7L.  It's free, takes under a minute, iand is worth looking into, IMO.

I used to have a battery disconnect switch on my Express to deal with a parasitic draw (have since swatted that bug).  The van would stall when idling after warming up, which was unnerving and potentially very dangerous (one good power brake; one good power steer--you know the feeling).  Stepping through "idle relearn" cured that issue.

Also, I agree that the 5.7L is especially sensitive to fuel pressure, and the filter is a good place to start.

One mechanic suggested to clean the throttle body so that is on my to do list tomorrow I will see if there is a process for this year model