Missing?

[gpchris]

My green gp (95 3100) started running like crap the last few days. Its shakes and has no power. Sometimes the rpms jump around on their own while accelerating. It runs like it did with bad spark plug wires but i changed the plugs, wires and coils.. No codes, what do you guys think it is?

[GnatGoSplat]

Sounds like a coil, but you said you already replaced them. I'd check them again, who knows, a new coil could go bad.

 

I check coils with an inductive timing light... basically just to see if it makes the xenon bulb flash fast and steady or not.

 

[Crazy K]

I do a simple phillips screwdriver in the end of each plug wire. if you have an extra/old wire you can use this instead of pulling every plug off the plug. basically spark check all 6 coil contacts for a healthy blue spark.

[jman093]

Kind of what my old Lumina did when the TPS went bad. Try unplugging it (will throw SES light) and see if it runs better.

[tornado_735]

Kind of what my old Lumina did when the TPS went bad. Try unplugging it (will throw SES light) and see if it runs better.

 

X2

[gpchris]

I unplugged the TPS and it ran the same just a little worst. I replaced it and it still runs like shit. No codes. Should i try replacing the ICM?

 

I unplugged the cam sensor and it nothing changed. What does the cam sensor control?

[tornado_735]

The cam sensor tells the computer where your cam is in it's rotation. The info is used to determine spark timing and fuel delivery.

 

I got this from http://bit.ly/MixnI

[jman093]

I unplugged the TPS and it ran the same just a little worst. I replaced it and it still runs like shit. No codes. Should i try replacing the ICM?

 

I unplugged the cam sensor and it nothing changed. What does the cam sensor control?

 

You didn't need to replace the TPS if unplugging it didn't help any. Don't replace the ICM yet. Take if off and have your autoparts store test it.

 

Also, has the fuel filter ever been changed?

[gpchris]

Well the icm tested good.. Again it runs the same when the cam sensor is unplugged.. Is that normal? And no the fuel filter hasn't been changed in quite some time.

[tornado_735]

Well the icm tested good.. Again it runs the same when the cam sensor is unplugged.. Is that normal? And no the fuel filter hasn't been changed in quite some time.

 

I would do the cheap stuff first, and change the fuel filter. I would think that if the cam sensor, even if it's bad or failing, would kill the engine if it's unplugged. Unless it's completely failed, and it's reverted to a 'limp' mode. That being said, I think it would throw a code.

[gpchris]

Well it runs the same with a new cam sensor.. I just don't see it being the fuel filter. This problem started it out of no where, wouldn't a fuel filter clog over time?

[hotrodolds]

Could be a PCM, bad LIM gasket, and it's drinking coolant...

[88red4cyl]

Have you ever verified that the coils are making good spark? I see where you got the ICM tested, but nothing about the coils...

[gpchris]

I replaced the coils.. I've played with cars long enough to tell you it's not a PCM.. It basically just shakes and doesn't have any power. How do I test for good enough spark? I guess I could start disconnecting the wires to see if I can find a dead cylinder.

[hotrodolds]

Dead injector? Can you hook up a scan tool to find the miss? If so, change out plugs, wires, injectors, and see if it follows. You know the drill.

[gpchris]

Dead injector? Can you hook up a scan tool to find the miss? If so, change out plugs, wires, injectors, and see if it follows. You know the drill.

 

I'm afraid it is a dead injector. I'm gona try the map before I take off the manifold

[tornado_735]

Well, if it is an injector, troublecodes.net doesn't have a code for fuel injector circuits, so I would try to find the dead cylinder first.

[gpchris]

ok i changed the fuel filter and it made a huge difference. Before it was shaking badly now it just has some decent power loss. When i turned the fuel filter on its side BLACK gas poured out of it. I probably clogged some injectors didnt i?

[xtremerevolution]

sounds to me like its time for a couple cans of seafoam, one in the gas tank and one in the intake.

[dylan1630]

This just happened to me yesterday, I found out my 93 green SE grand prix was only running on 5 cylinders, a coil was bad. it would shake real bad when accelerating because it was missing so bad. The idle air can cause your car to miss/stall if it's bad, but your problem sounds more like a coil... or and injector isn't running, it sounds like it's not running on all 6 cylinders.

[tornado_735]

If it does turn out to be a bad coil, change your oil asap because you could be dumping raw gas into the oil, which is not good at all. Also, you may have damaged the Cat, depending on how long you have been driving with it like that...

[gpchris]

I just remembered ever since the missing started my security lights been staying on.

[GP1138]

I can't imagine why the VATS system would cause a miss. Sounds like a wiring/electrical issue. Have you checked the integrity of the wiring? And do you have a spare 3100 PCM you can try?

[GnatGoSplat]

Could be a bad PCM or a shorted injector overloading the PCM.

 

[gpchris]

While replacing the injectors I tested for injector pulse. Half of my injectors arent even pulsing which would explain why my friend thought my car was a 4 cylinder.. I think it may be because of the injector harness. Copper wire is exposed near some of the injector plugs. That or the pcm isnt sending a pulse.