Gregory Higbee

i have a 1993 chevy corsica with the 3.1 liter v6 3-speed auto trans. recently ive begun to have a really bad problem. whenever i drive the car, the tachometer starts going wild along with the speedometer, and then if i use my turn signal or press the brakes, the car dies. ive checked all my fuses, and some of my wiring, but im not really into the electronics (more the mechanics) of cars. if you need more background on the car, it has had a few problems before, but i fear that this one problem will do more damage than the various fixes before. i leave on the 21st of Sept. for college and i really need to fix this problem before i make the 5 hour trip to the campus. it was more intermittent before, but now its become an almost every drive thing. suggestions would be greatly appreciated!

Gregory Higbee

**update** through some research and talking with a few others, i found that the problem could be related to my ignition control module, still unable to figure out what or why it would be having this problem

92chevycorsicalt

I'd replace the control module and all 3 coil packs

GHOSTOWLGRID

I do not think it is the ICM, it is most likely that you have bad wires.
Corrosion or leaking to ground...
But you can change it with one form a junk yard if you want, most likely nothing will change...
The ICM is in no way connected to the speedometer and other gauges, but it is connected to the tach...

And when you say it dies when you press the break, and the gauges act funny, it leads me to believe you do not have 12 volts when the car dies, it shorts to ground or maybe it was never there...
Recreate conditions and use a volt meter during the event.

I suggest a wiring harness from a Beretta or Corsica of the similar engine & year if your alternator is not borderline bad...

sdickens65

i have a 98 s10..in my shop//with a 2.2.
the problem is an intermittent no start no crank...which i knw can lead you in 1000 different directions.
but heres what ive done..
i have replaced the keyswitch and lock cylinder..was worn..and the small wiring harness that goes from keyswitch to ecm.relearn process has been completed.
rewired clutch switch once..and lter disconnected.
found an after market keyless entry and alarm that had been hooked up and disconnected by previous owner..and bunched up under the parking brake..so i disconnected and bypassd all of that..cause it was grounding out behind the park brake pedal..been in to the wiring harness from pcm to make sure there no loose connections from key to pcm..nothing..
and still has the no crank issue goin on..just once in a blue moon..the guy will come out to start it up and gets nothing..
could there be an issue somewhere in the instrument cluster?
ive seen that happen on several vehicles but never on a chevy..

thanks
shawn

GHOSTOWLGRID

Well from what you say, I would assume that someone screwed up the wiring big time. Make sure everything is properly fixed first.

Then check trouble codes. If it turns the key and you do not have anything turning under the hood, then you lack connection to the starter.
If this have a chipped key, which I believe it does not, then make sure there is signal to the ECM from it. If so, it is possible that your 3 starts were used up and the ECM thinks the car was stolen and locked the engine from running.

If the engine cranks, check spark, check fuel, and check air, also check sensors. Check fuses first before anything.

1) Sometime the oil pressure sensor can tell the ECM to turn off the vehicle if there is no pressure detected.

2) Sometimes the ICM can be faulty causing crank and no start. because there is no spark.

3) Cam position sensor, if it has it, usually doesn't stop it from running, its for higher resolution.

4) And the second CPS if it has it will not keep it from running either, that is for higher resolution as well.

5) The CPS in the back of the block is the one that directly runs the spark timing, that signal is the modified with the other two sensors from #3 & #4.

6) MAP sensor and MAP sensors, these the engine can run in defualt without pluged in. usually a way to test if its faulty or not.

7) Check you have fuel pressure. And check to make sure your getting fuel and your injectors are functioning properly. If just one faults out, the ECM turns them all off to protect itself and the engine.

8) I do not know much else, I am not there and I can not look at it myself. If I was there I could have it diagnosed in under an hour and that can possibly include repairs.

There is not much to the 2.2L engine. It should run with almost everything unplugged. But it would not be smooth. lol

We own an S-10 Pickup Truck, it is a 97. I've never had any issues with it, it just works.


I do not know if they added anything more in 98, the 97 just has the ICM, ECM, CPS, EGR, MAP, MAF, Oil sensor, coolant temp sensor, and that is it basically. Not much to fix.

The instrument cluster is just a readout from the ECM, I highly doubt something is wrong with it, easy way to check is to unplug it.

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But aside from all that, if the wiring is butchered up, chances are its gotta be fixed. The above is just if you know for sure the wiring is properly repaired.

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If I had crank from the starter and no start. here is what I would check in this order:

1) vacuum lines if any.
2) Spark at each cylinder.
3) Fuel pressure.
4) Sensor redouts.
5) Sometimes I switch it up depending on the symptoms.
*Always check fuses first. lol

sdickens65

all that has been checked and gone through..i have even replaced the cam and crank sensor.and no there no 2nd cps..only the one.i just recently bridge over the clutch switch..and it lasted about a week..and he just called me again today and said it was doin the exact same thing..new keyswitch,new sensors..and rewired all the bad wiring job that done prior to these events...i dont know of anything else it could be,,,thats why im kinda reachin out here.lol
im bout ready to take ahammer to it.lol
could it be a faulty ecm or bcm,or maybe even a shorted starter circuit????

GHOSTOWLGRID

Okay I'm a bit confused, and sorry it took a while to get back.

I want a complete list of what was replaced:
Here is my thoughts please correct me if I am wrong:

Working:
1) CPS-A
2) CPS-B (Does not exist) These are behind the harmonic balance pulley.
3) Cam Position Sensor.
4) ICM.
5) Coil Packs.

I am considering that the ECM might be at fault. Its a truck, was it abused? Water in the car/ecm?

I'm starting to think that it might be possible there is a borderline bad injector causing crank and no start.

But because there is no crank causing no start, I might say you have a problem with the starting circuit, or you have a problem with the starter.

I had a bad starter one time, it failed on half the coils or whatever you call them, so it was weak and sometimes it did not turn. Sometimes it made contact and worked like normal.

Bad starter coil?

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If the starter is directly wired to the starter switch in the column, then it should crank given a battery with a full charge.

Do you get voltage at the starter when required?
Voltage at the starter coil signal?

If the ECM is to blame and you have an ECM connected to a chipped key, then possibly there is either a bad connection, or the ECM is bad.

Those 2 wires into the key area are for the warning beeper your key is still there.
If there is a 3rd or 2 more wires, then there is a chip probably.

When you say key switch did you replace the sliding thing that the metal rod moves from the key in the column that selects and changes contacts between the start-run-accessory-off positions?

An easy way to rull that out would be to identify the proper wires, create a jumper and stick it in the prongs and see if you can run the starter.

Check for proper voltage uner the column?

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I'm lost, I'm afraid I can't really help you much more than this without seeing the vehicle myself and messing with it.
Good luck, I'll try my best if anything new comes up. Good luck.

sdickens65

the 1) CPS-A
3) Cam Position Sensor.
4) ICM.
5) Coil Packs
and key switch,,repaired broken wire from aftermarket security system that was ltr bypassed and bundled up by the e brake pedal...
sorry after market keyless entry and alarm..
relearn process complete..
im not thinkin there is an issue with ecm yet..i recently replaced starter and so far it hasnt done yet..but its only been a couple of days.
its been happening after driving it a while after fixing one thing at a time..you fix thing.and it does it again a few days later...
havent tested out the ecm yet..cause didnt really think that was issue givin the fact in pror expereinces..have checked all wiring under dash and under hood..and sorry but i do not the prior history behind the truck,,and neither does the customer..unfortunatley..

GHOSTOWLGRID

Replace or have the alternator tested and tell me if it happens again.
Test your battery and make sure it is proper, make sure the battery has solid connections.

If thats not it, your wires are shorted.

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I had this problem just recently, turn signal and breaks made car stall and gauges went nutz.
My battery had a lose connection, alternator could not keep up with the demand fast enough.

Another time this happened, I had a weak battery and a weak alternator,
I replaced the alternator and then charged my battery, never had any problems ever again.