I have a 94 Caprice and it is giving me a headache. I would drive it and it would cut off as i was driving but i had no specific time frame in which it would happen. I repaced the timing chain, erg valve, distributor, spark plugs, wires. So i got it to start drove it and it did the same thing. I let it run in the driveway and it cut off and stummbled (the engine). So i thought another PCM and it contines to stumble. When u try to crank it, it just continues while i turn the key and when i release the key it ask as if it wants to continue to crank for about a second and a half. Please help

Well, if its not starting it will be easy to diagnose…

  1. check fuel pressure
  2. check for spark
  3. if it stalls intermittently probablynot an internal engine issue, but if you have spark and fuel and no start- check compression in all cyls.

do this and report back.

You need to use test gear now; so, put aside the wrenches. Can’t? Pay someone who can. What other choice do you have?
If you want to do the tests, you need some basic test tools: an electrical multimeter, a fuel pressure test gauge, a vacuum test gauge, compression test gauge, and instructions in their use. Do you give up?

and he has to know HOW TO USE THEM

I had a similar problem once. Turned out to be a bad ignition switch. The electrical contacts were internally broken and causing intermittent connection loss. The extended cranking may be a signal to check for problems here.

Just remember, the ignition switch is different than the lock cylinder. The ignition lock cylinder pushes a rod that moves the actual switch located on the top of the steering column under the dash board, not just behind the steering wheel.

If the engine really does stumble, and then stall, that seems to more of a fuel into the engine problem. And, it might be a fuel to the engine problem.
You can find out if the fuel pressure is falling off, and causing it to stall, if you tee-in a fuel pressure test gauge, and watch the gauge while the engine runs.
If there is fuel pressure, but, it won’t start, the problem is lack of fuel injection. To check that, spray some starting fluid into the intake tube while cranking the engine. If that doesn’t help, check for spark and check the ignition system. There are instructions for doing that in the repair manual, like Haynes or Chilton’s, which will help you with that.
As far as just changing parts, swap out the fuel pump relay with another one in the relay box, just to be sure it’s not that.

it firing, but how can i check the feul pressure if it is not cranking

Based on the symptoms I agree that it could be an ignition switch or fuel supply problem; or both.

Plugs, wires, EGR, timing chain, is not going to cause a problem like this.

but it was idling fine then all of a sudden this problem occurred. It didn’t completely shut down but it was as if the car was choking itself out. So if the car was running then started to have this problem so the ignition switch had already been engaged before this problem occurred. Just had the fuel injectors cleaned but it almost sounds like that this is the problem. Put a new fuel pump and strainer in it about a little over a year ago. The fuel pump is comming on but did not replace the fuel sending unit but before i put the tank back in place i tested the fuel pump and it supplied gas throung the sending unit.

Does this mean you don’t have a fuel pressure test gauge, and don’t know how to use one if you had one? This is one of those instances where there is no substitute for basic test equipment. I feel that we’ve taken you as far as we can until you get the fuel pump pressure test and information. You can do it, or have someone else do it; but, it needs to be done.

fuel pressure was fine from the fuel pump. Filter was in good shape. And it just continues to stumble when trying to crank. It seems that it want to crank more after i release the key than it does when i am actually tring to start it.

Uh, to me the symptoms sounds like bad gas or water in gas that’s causing the “dieseling” feeling. When it stalls, doesn’t die right away. Could bad gas be an issue, has this car sat for a long time?

If gas quality isn’t an issue, try what hellokit is suggesting.

Are you saying this dying only occurred at idle? The way I read it, and may have misinterpreted it, is that the car would die as you were going down the road at speed.

If it’s dying only at idle then consider an Idle Air Valve problem.

How do you think we can help you? Can we say, “Change part so and so and everything will be fine”? With the problems your car has, we can’t do that.
You need a decent voltmeter-----one where you can tell the difference (on the scale) between 12 1/2 volts and 12 3/4 volts. Got one?
Go under the hood, and remove the lid from the fuse box. Remove fuses #2, #4, #6, and #9. This is for testing the ignition switch and the wiring from it. Wrap a straightened paper clip around the positive (red) voltmeter test probe. Attach the negative (black) test probe to an unpainted part of the engine.

Have a helper turn the ignition switch ON (RUN). Take a voltage reading of the battery, and write the value down. The voltage should be about 12 1/2 volts. Place the voltmeter red test probe into the terminal of the fuse socket side that has voltage. [#2 fuel pump power; #4 EMI - engine computer power; #6 four fuel injectors power; #9 the other four fuel injectors power.]
Check the voltage in #2 fuse socket in RUN position. Your helper, again, turns the ignition switch off and, then, to RUN. You check the voltage again. Do it again, and again. Every time, the voltages should be within 1/2 volt of the battery voltage. If not, that is the circuit which needs further testing.
Check the voltage, in the same manner, on fuse #4, #6, and #9.

The spark plugs may be fouled. Yes, they can foul in a very short time. Remove as many of the spark plugs as are easily accessible. Compare the spark plugs to these, and let us know which ones match. We’ll advise you from there.

I checked out the spark plugs and look at them and they were in good condition. But i replaced the with new ones. But i found that for some reason they continue to get wet with gas. I guess the information will be helpful to know and maybe you can assist more. I also replaced the idle air valve and it contiues to due the same thing. But it might be something with the spark plugs getting wet. I there any way to check to see if the fuel injectors are any good and/or working properly?

If the spark plugs are wet with gasoline, that shows that there IS fuel injection. Now, there can be too much fuel, or there can be no spark. Either way, the fuel won’t burn, and the engine won’t run.
You said you checked for spark; but, did you check for spark when the engine wouldn’t start? You need to check for spark now while the engine is NOT starting (during cranking). I suspect that there isn’t spark, right now.
On the other hand, there may be spark; but, there is so much fuel that it’s putting the fire out. Try this: remove the #6 fuse to disable four fuel injectors; crank the engine. Does it start a little better? Now, put #6 fuse back in, and remove #9 fuse. Crank the engine. Does it, now, start better?
If the engine starts, or runs, better with a fuse removed, some (or all) of the fuel injectors are spraying too much fuel on one side of the engine.
Another way to dilute the excess fuel with air, is to disconnect a small vacuum hose, and try to start the engine. If it starts, that shows that part of the problem is over-rich fuel (we can talk about that after you do the checks, and get results to us).

Sorry to keep bothering you but i do want to say thank you for your time and patients. I performed the following steps that you listed and it shows no sign of cranking. It has excellent spark. Swapped plugs out (put dry in dry ones). Unplugged vaccum line but nothing. I am just trying to wonder why was it idling and all of a sudden it acted as if it was choking it self out. The diagnostic machine is not giving me any code for it.

Have you checked the fuel pressure regulator? Remove the vacuum hose to the regulator and see if there’s gasoline in it.

If there is, the diaphragm in the regulator has given up and this will allow raw gas to be inhaled into the intake. At speed, it’s possible this extra gas could be burnt for the most part but at idle or very low RPMs can cause the engine to load up and die.

do i need to remove it from the car or just take the vacuum hose off. I took the vacuum hose off and nothing came out of it. So thats why i asked.