95 2500 stalling problem

[indy72stepside]

OK, this has happened to me 3 times now. The truck will just stall out going down the road. It is like someone turned a switch. The first two times it started right up, this last time I had to crank on it like it was not getting fuel. No codes and it runs fine otherwise. any ideas?

Jeremy

[Zkast]

Assuming this is a pre 96 model non vortec engine?

Right off hand I would say it sounds like a ignition module failing when hot. There are a few other things that are known to cause this (fuel pump, injector harness short to ground)

Do you have a timing light? Hook it up and run the light inside the cab. When it starts to act up, pull the trigger on the light and crank. if you have a pulsing light your ignition is most likely ok.

If it is the module, replace the cap and rotor while your there. typical GM black plastic ignition componant failures

[ThreeQuarter]

Of course it could be any one of several things, but does it start happening when you get to a certain fuel level? I had my fuel tank baffle come loose and screw up the fuel pump "tower" in the tank. I couldn't get the last 10 gallons out of my tank, and it would run out of gas with well over a 1/4 tank showing on the gauge. Check the electrical stuff first, though.

[indy72stepside]

fuel level does not matter. Engine temp does not matter much either. I will try the ing mod., but in the past, when those have gone out, they have gone out not interminnent(sp?)

J

[Zkast]

If I had to guess, more often then not we (our shop as a whole) see more intermittant module failures than total failure. Majority of those are ferds though

Its a common failure, try a timing light on it.. you'll know for sure if your problem is in the distributor (pickup coil/module), Pickup coils usually do not cause this symptom.

[Chevyman69]

Ignition modules are intermittent usually and in a lot of cases never throw a code. There are other things too, but if you can't ever remember replacing the module, or it was a cheapie if it was done, thats probably the problem right there.

[indy72stepside]

took the control mod to autozone and it tested Ok. We hit it several times to try and get it hot so it would fail but it still passed. The cap ant rotor looked good. Any other ideas? I had a similar problem in a camaro and it ws the fuel pump relay, is there one on these trucks? It is kind of hard starting also if that matters.

J

[Zkast]

Not that there couldn't be other problems but the module test you just described wouldnt show a intemittant problem.

By the time you get the module in the store, wait for them to run a test? its cooled down enough to make contact again. Even if you were in the parking lot of thier store.

The only way to test for a module problem with your symptoms is to do what I have described. Even that is not a truely postive test, meaning it will only tell you if there is no spark (commonly caused by the module).

Your first step in diagnosing this is to verify WHY its dying then you can determain whats failing.

Is it dying because of no fuel? No Spark? Mechanical problems?

The only reason I mentioned a timing light is because in most cases that is what I use any time I have a car come in with this type problem. I can quickly verify if its loosing spark or fuel with a scanner or timing light. It also allows you to drive down the highway if need be.

Anyway, when it dies you need to use some method of determaning if its loosing spark or fuel, then move on to the next step. If you can get it to die on a regular basis, call me (913-707-9337 cell) when its not starting and you have someone there with you to crank it. I'll guide you through some quick easy steps to find out what the problems are without spending money on something thats not bad.

[indy72stepside]

if it becomes a regular problem I will call, it does start back up and has not left me stranded (yet). I hate these types of problems. When it does quit, I can let it set for maybe 30 sec. and it will start right up.

Jeremy

[Zkast]

They arent much fun for us (techs) either lol. We charge a 79.95 diagnostic fee to start running checks, but typically it can take anywhere from 15 minutes to 2 hours of checking/driving/checking again....

They suck thats for sure.

Dont hesitate to call, I'll have my phone with me all the time. I'd be glad to help if I can.

[indy72stepside]

I went to napa and bought a new one just for the hell of it. So far it has not acted up again (fingers crossed) I wrote down your number and have it ready. Thanks for the help. Now if I could just get the emissions back on the Z-28 all would be right with the world. You don't happen to have a good pic of the engine compartment of a 92 TPI Camaro do you?

[Zkast]

Not right off hand but the next time one comes into the shop I'll snap a shot for ya... Usually see one every couple of weeks.

[indy72stepside]

thanks for all the help, I am going to try to throw something together to pass emissions, but a pic would really help
Jeremy