Weird problem

[Chionos GMs]

My moms 92 suburban has been a handful. It was randomly shutting off while normal cruising so we replaced the module, cap, spark plugs, computer. The computer solved that problem for the time being then it started actin up again and fuel gauge stopped workin so we replaced the fuel pump then it ran fine then we replaced the ac system and all that good stuff. My question is now the truck shuts down randomly again but its only once in a blue moon but still makes my mom not want to drive it. What can be the cause of this? is there parts in the steering column I should replace?? Im tryin to be a good son haha but this makes me want to Thanks guys

[ChevLoRay]

Is the Check Engine or Service Engine Soon light on? I can't help but believe that it is, or if not, then it has to be storing some codes. All of that can't happen w/o storing some codes.

Since you have an OBDI (pre-96) vehicle, you'll need to use the ALDL connector and trick it into flashing the codes. There are posts on here that tell you how. I'll see if I can find one for you and add it to this post as an edit.

[Chionos GMs]

I know how to read codes but when I do it no codes pop up and thats whats weird too. Thanks

[ChevLoRay]

Check out this post. I read that you know how to check for codes, so that's good. There are other suggestions that may be of interest. Seems like this thread is similar to your situation.

http://67-72chevytrucks.com/vboard/s...aldl+connector

The Snap-On code reader is a very advanced system, and if you know anyone who has one who will do a system scan for you, it may show you some things that don't otherwise appear.

[Chionos GMs]

Thanks. Can anyone tell me where this goes http://shop.oreillyauto.com/ProductD...pe=200&PTSet=A the only part I didnt replace I think

[Boog]

That goes inside the distributor. It has to be removed and disassembled to replace that piece. As far as I know the pu coil either works or doesn't, not intermittent.
Your situtation sounds more like a matter of a weak electrical connection somewhere.
I had a random shut off on my Burb at one time but it turned out to be the wiring harness inside the fuel tank. Once I replaced that harness and fuel pump it cured it but since you have already replaced the pump that may rule that out. How about ground wires?

[Chionos GMs]

We checked all the ground wires and cleaned up the grounds. Also you can start the truck with no key could this have anything to do with it??

[TennesseeZ]

Could be, how many miles on it? I'm assuming a lot? I've had problems with ignition switches that caused symptoms like you describe. On your 'burb, it's on the top of the steering column, under the dash. Not the key switch, they are two different things. Also take a good look at all the wires and connectors for it too.

Starting with no key points to the key switch, you may want to replace it also. If you need help with either, let us know.

[Chionos GMs]

The key has no grooves on it. The po said someone jammed another key in it and now it starts with no key. So I should replace the key switch? and I will check the ignition switch. Thanks

[TennesseeZ]

Originally Posted by Chionos GMs

The key has no grooves on it. The po said someone jammed another key in it and now it starts with no key. So I should replace the key switch? and I will check the ignition switch. Thanks

So actually, it is starting with a key, you just can't get that one out. I'd still replace it, if you can start it that way, then anybody can. With your permission or not. Cheap insurance if you ask me.

[Chionos GMs]

The key is not jammed in there anymore because he pulled it out. I was planning on replacing it anyway but am wondering if this has anything to do with it?

[TennesseeZ]

Probably not. It's basically just a mechanical lock like the door lock, it has no electrical function at all, unless it is one of the PASS keys with the little "pellet" in it. I don't think yours has that, does it? But instead of operating a door lock, it mechanically locks/unlocks the steering wheel and operates a rod which activates the actual electrical ignition switch, which is mounted on the column under the dash.

I can't guarantee that the (electrical) ignition switch is your problem, I'm just throwing out the possibility, based on my prior experience.

[Chionos GMs]

Alright cause I was playing with the key switch when it was running and the truck shut down. I played with it 3 times with the same result. Im goin to check wiring because my mom says it seems to only do it only over bumps

[Boog]

I'd say start with the things you know are wrong with it like this key switch and make sure it operates smoothly, properly. Then move onto the next thing. You'll narrow it down.

[TennesseeZ]

Originally Posted by Chionos GMs

Alright cause I was playing with the key switch when it was running and the truck shut down. I played with it 3 times with the same result. Im goin to check wiring because my mom says it seems to only do it only over bumps

If it's that loose, then it could be letting the electrical switch turn off, while the actual key switch is still in "run'. I'd replace it first. I don't think there's any real "adjustment" needed on it, if any is needed you'll do that at the ignition switch, IIRC.

[Chionos GMs]

This truck has been an since she got it but I guess the price was right but still makes want to cause I aint old enough to yet . Thanks guys you really helped me

[ChevLoRay]

This probably won't apply to your truck, but I find that a lot of key issues on older vehicles can be fixed with a new GM-cut key. Take your VIN to a GM dealership, with PROOF of ownership, and they can cut you a brand-new key. It's an amazing piece of metal that solves a problem, UNLESS the switch or door lock has been changed. But the majority of them haven't and the new key will be a welcome addition to your key ring.

[chevytroy]

check battery cables i have a 97 tahoe drove me nuts come to a stop light shut off would restart . the side mounts suck.... on codes for that also the fuel pump it has a check valve so the gas doesnt back feed to the tank. mine pump worked fine as soon as the pump kicked off i would lose the pressure. to check that turn the key on dont start the truck. let the pump pressurize it will kick off listen to hear your tank bubbling. last but not least its a 92 so it has a hei ignition module. its in the dizzy two torque crews hold it in. heat from the block tranfers to it shuts it off, engine dies and there is no code on a obd1. i repalced every thing ecu/pcm every sensor. wires cap rotor plugs injectors. i was at a lose the hei 20.00 five minutes a t20 driver truck was running greater the it had ever before... good luck hope i could help any

[Chionos GMs]

It threw a code 4 flashes and 2 flashes sayin ignition module but that was already replaced. Im goin to replace the key switch and then check ignition switch wires

[ChevyTech]

A code 42 will get set when the set timing connector is unplugged to set the timing. Make sure you clear the codes after setting the timing.

If you have not set unplugged the set timing connecter then you are on track to find the problem.




He is some code 42 information:

A code 42 is set when the ECM loses communication with the distributor.

Code 42 can be set by a bad distributor module, a bad ECM or wiring problems between the ECM and distributor.

A code 42 will get set when the set timing connector is unplugged to set the timing. Make sure you clear the codes after setting the timing.

A bad distributor module is a common cause for this code.

Many stores like NAPA in my area will test the module for free if you bring it in.

Make sure when you install or reinstall the distributor module that you use heat sink compound/grease under it. The grease helps dissipate heat from the module. Without it, the module will fail.

Edit: Also take a look at the terminals in the connectors that plug on to the distributor module. It is common for corrosion to cause problems like you are having.

[GASoline71]

Originally Posted by ChevyTech

Make sure when you install or reinstall the distributor module that you use heat sink compound/grease under it. The grease helps dissipate heat from the module. Without it, the module will fail.

To add to the great info ChevyTech already gave. Make sure it's not dielectric grease that is used. A lot of cats think dielectric grease is heat sink compound. Two totally different animals. If dielectric grease is used, it will not help dissipate heat, and the module will fail.

Gary

[chevytroy]

have them test that bad boy 5 to 7 time it will pass pass pass fail its no good i spent alot of money to figure that out on my own.

[Chionos GMs]

We replaced it and used heat sink not to long ago before the ecm was replaced. I will have to have it tested. Where is the timing connector located?? because I dont know if the smog shop reconnected it after re timing it! Thanks guys

[ChevyTech]

Originally Posted by Chionos GMs

... Where is the timing connector located?? because I dont know if the smog shop reconnected it after re timing it! Thanks guys

For your 1992:
The set timing wire, which is a single Tan wire with a black stripe/tracer on it, is located, under the hood, on the main harness that goes from the engine to the firewall, on the passenger side, sometimes underneath the black plastic cover (if it’s still there) that covers the junction block, relays & fuses. It’s near the top usually on the back side of the harness. From the factory there is what looks like black tape around the harness holding the set timing wire to the back of the harness.

[Chionos GMs]

I found it where does it end up going to on the engine? Also I found a two prong connector with orange and a black wire going to it. Do you have any idea where it should be connected to??