Blaze of Glory

92 3.1L V6

Several months ago I was accelerating to merge on the freeway when suddenly my car lost power. I had to push the pedal down further just to maintain freeway speed. After a few miles, the pedal was to the floor, the revs were high, and the car was barely going 50. (At first I thought it might be the tranny) When I slowed down after getting off the freeway the car started stuttering badly and died. It started up a few more times, each time it had no power and choked. Eventually it wouldn't start again.

I wouldn't even say the car runs. It turns over just long enough to choke and die. Smoke comes out the tail pipe , it's not very thick, it's not very black or white, just a pale grey smoke and a weird smell.

I've checked the fuel pressure (about 42, doesn't drop much while turning over) But i'm not sure what else to check. The CEL isn't on either. I'm really not sure what to start checking first. Thanks for any help!

oH HorizoN

Greyish smoke is fuel. White smoke is steam/water, bluish/black smoke is oil, though black can sometimes be fuel, too.

Anyway, I'm pretty sure it's a fuel problem, or at the very least, the engine is getting too much fuel, or it's not being able to burn it properly. This leaves air, spark, and possibly the fuel injectors themselves (assuming the pressure is proper and good after the pressure regulator).

The suddenness of it makes me think something mechanical or physical, not necessarily a sensor or something. Have you looked in the intake at all, maybe even the throttle body? Have you checked to see if spark is happeneing in the cylinders? That's where i'd go next.

Just remember, at the base of it all, you need Air, Fuel, Spark, and Compression in order to run an engine.

ahankins32984

Mine 86 Z28 did the same exact thing and my part was the Ignition Coil died I would check Distributor assembly after checking the fuel pump!!!!

lunaticinaZ

A clogged cat. converter can cause the same issues. If you can get the car to run the cat. will get very hot real fast if it is clogged and there wont be much exhaust flow coming out the tailpipe. If that is the issue don't run the car for very long, it can damage the engine.

Blaze of Glory

What would cause excessive fuel to be delivered? I installed the F1ZE injectors almost three years ago, but I don't think they would all of the sudden fail. If it was just one injector, maybe, but if it was just one injector the car would still run, just very poorly.

I wondered if a bad vacuum leak could cause this problem. I've check all the hoses for obvious leaks, but I could see anything.

What's the best way to check for a spark at the cylinders?

Edit: Oh yeah, another thing, the car had just been smogged a couple months before it died and it passed with flying colors.

Carlos91GTA

I agree with ahankins32984. I had the same issue with my 91 GTA. After going through a bunch of trial and error parts with no success it turned out to be the ignition coil. Granted I still need to replace my exhaust for it to be a 100%. The ignition coil was the main problem.

Blaze of Glory

Well, I replaced the ignition coil when I did a dizzy rebuild not too long ago. The car was running fine, but I wanted to just change everything out. I think I still have the old one. I will try changing the coil.

If it's not the coil, whats next?

oH HorizoN

Doesn't your year utilize a MAP instead of MAF? Idk how MAP's work, as I have a MAF sensor, but I do know that those damn electronic sensors have been the bane of my car's existence for a long time.

ASE doc

Have you checked spark? Or injector pulse? I would suggest a little diagnosis before you start changing parts.

Blaze of Glory

Injector pulse??? How would I go about checking that?

Also, whats the best way to check for spark? Pull the spark plug, put it in spark plug cable and try to start the car?

ASE doc

That's one method. The safest and most effective way is to use an inline, bulb type, spark tester. You can buy one cheap at your local parts store. The bulb will flash with high voltage. To check injector pulse, unplug an injector and insert a noid light. You can buy a noid light at your local parts store. Don't forget to check fuel pressure, should be 40-45 psi. If you have fuel pressure, spark and injector pulse and it still wont run, disconnect the MAF sensor and try to start it. If it starts with the MAF unplugged, the MAF or MAF circuit has a problem. If it still wont start, remove the O2 sensor to vent the exhaust and try starting it. If it starts this way, you have a clogged cat. On top of all this, you may have fuel fouled spark plugs from cranking it will the injectors squirting fuel into the cylinders and the engine not starting.

tbutle03

Ok Ihad the same issue excatly last week! Its your spark take the wire of your coil touch a bolt on the motor and have some one try to start the car the spark from ur coil should jump almost a half of an inch and be a nice blue color. when mine died it did all u discribed but i had a weak spark mine was dim and short. Now if that is good check the wire buy sticking the screw driver in were a plug goes and try to start it while hovering the end over a bolt it should be a nice blue spark. Also if you havent yet i advise you to put new plugs in and wires cap and rotor if you havent already and there are small metal prongs that go around the distributor while you have the cap off take some sand paper and clean the prongs they could be rusty. But ur problem is diffently spark dont listen to the people that are saying gas or timing because there all nuts. If you need help just call 8107063178

ASE doc

Excuse me? Did you say that we are nuts for suggesting that he check any possible cause? But then I've only been a GM tech for 20 years. What doI know? And have fun checking spark on your HEI ignition by holding the coil wire in your hand. That's a good way to get knocked on your butt.

oH HorizoN

Haha, wow. Seriously?

Blaze of Glory

Thanks everyone! I got a chance to work on my car last night and I think I solved the problem.

It was the timing.

The car barely ran as long as I kept jogging the throttle, but it ran enough for me to see the timing mark was almost at the 3 'o clock position...way way off...

I loosened the dizzy bolt, adjusted the timing, and it started running smooth again...


I know for a fact that the dizzy did not move, especially not by the extreme amount required to throw off the timing so bad. So what could throw the timing off so badly?

I immediately felt stupid because this isn't the first time it happened (although this time was worse). When I first got the car (12 yrs ago), and before I had ever worked on a car, my car started running very bad, I took it to a shop and they said the timing was off by 20 degrees. The problem presented itself in the same way, in the middle of driving when all of the sudden the power goes away.

ASE doc

Be sure that the dist hold down and bolt are in good shape. If the hold down is bent or deformed in any way, replace it. Some cheap after market peices don't really fit well even brand new. And it doesn't hurt to put a heavy(machine) washer between the bolt and hold down to assure proper torque retention. Actually on many I also add a split lock washer on top of the flat washer. With these precautions taken, mark the base of the distributor where it meets the manifold with black permanent marker. If the problem occurrs again, you will have the mark as referrence to be sure the dist did or did not move.

Blaze of Glory

I am absolutely certain that the dizzy did not move. I've messed with the distributor enough times to know the approximate position it was in. I had to move it quite a bit to correct the timing. Also, the hold down bold was on the tight.

Also, if it was a loose hold down bolt, I would think the timing would change gradually, not all of the sudden...

ASE doc

That leaves an internal fault in the distributor, timing chain, or an EST fault either in the dist or in the ECM. Unlikely that it's the ECM. Remove the cap and look carefully for any sing of damage to the timing core or pole peice. Check them for being loose on the shaft or dist base. The thing is, if this problem were internal to the dist, it can only shift so far before the secondary is going to start firing on the adjacent hole. Thew spark is directed to each hole by the rotor's alignment to the cap contacts. If the primary ignition pulse is out of sinc with the secondary system by more than 22.5 degrees, it will direct spark to the wrong hole and throw timing off by alot more than 20 degrees.

If the timing chain had slipped, especially if it had done it twice now, the engine would show signs of it like running very rough.

One other thing I can think of is the dist gear. If it is worn or the pin is sheared, it could affect timing. You may want to check that.