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My 95 camaro was running really crappy the last time I drove it. Sputtering and bucking and barely running and dying on its own. I got a cable and the scan program off this forum and scanned the codes and am wondering what to troubleshoot exactly. I’m not a big computer person or tuner I will attach a picture of the codes to show you what they are. I’ve gone through the possibility of a distributor, or some ignition problem. Any help is appreciated.
Best thing to do is download a (free, courtesy of GaryDoug) copy of the 1995 factory service manual, where the possible causes of each code are explained, and a troubleshooting logic tree is presented for each code.
If someone doesn’t offer some help by tomorrow, I'll do what I can to help. But taking a look at the FSM may give you a head start finding the problem. Any one of those codes could be causing the problem - ICM, Opti, or MAF. All three at once just makes it more difficult to sort things out. It may also be necessary to run a data log using Scan9495. I can review that for you.
Best thing to do is download a (free, courtesy of GaryDoug) copy of the 1995 factory service manual, where the possible causes of each code are explained, and a troubleshooting logic tree is presented for each code.
If someone doesn’t offer some help by tomorrow, I'll do what I can to help. But taking a look at the FSM may give you a head start finding the problem. Any one of those codes could be causing the problem - ICM, Opti, or MAF. All three at once just makes it more difficult to sort things out. It may also be necessary to run a data log using Scan9495. I can review that for you.
I feel very stupid. I realized I had my maf sensor unplugged because yesterday I took it off and cleaned it and forgot to plug it back in. But I started my car and checked and there were no more dtc codes at all which doesn’t make sense to me because the car was was still running like crap the other day and died on me in the driveway. So I’m just confused on how unplugging the maf would throw 3 codes and then plugging it back in would fix all 3 codes. I haven’t driven the car yet because I’m afraid it’s going to die on me again. But the fact that I’m not getting any more codes is confusing me.
Not all codes can set immediately on startup, or at idle. Some of them require the operation of the engine under actual driving conditions.
While an unplugged MAF will set a code, an unplugged MAF causes the PCM to default to the speed-density method calculation of the mass air flow. Might not even notice the difference in the way the engine runs, unless the engine is modified and the volumetric efficiency (VE) table in the program has not been updated.
Which brings up another info need - is the engine stock or modified. If modified, what mods? You really need to add a signature so people have the info they need to help you:
Not all codes can set immediately on startup, or at idle. Some of them require the operation of the engine under actual driving conditions.
While an unplugged MAF will set a code, an unplugged MAF causes the PCM to default to the speed-density method calculation of the mass air flow. Might not even notice the difference in the way the engine runs, unless the engine is modified and the volumetric efficiency (VE) table in the program has not been updated.
Which brings up another info need - is the engine stock or modified. If modified, what mods? You really need to add a signature so people have the info they need to help you:
I made a signature. Still trying to diagnose the issue. Haven’t drove it yet but I’m planning on it to see if the codes will come back on and go from there after I replace the wires. Plugs are new but wires have been on since I’ve owned the car for over 6 years.
DTC 36 for the Opti could be intermittent loss of the high resolution cam position signal from the sensor in the Opti. In theory, the engine can run fine without that signal - just a small increase in spark timing scatter and injector timing error. But generally not noticeable. But in reality it can cause rough running.
DTC 42 can be a problem with the ICM due to heat soak. Is the “crappy” running all the time, or primarily when the car has been driven for a while and the engine gets hot? Intermittent problems are harder to find. See how fast the codes come back, and whether it seems that the engine starts running poorly as soon as you start it, or after it’s been running for a while.
DTC 36 for the Opti could be intermittent loss of the high resolution cam position signal from the sensor in the Opti. In theory, the engine can run fine without that signal - just a small increase in spark timing scatter and injector timing error. But generally not noticeable. But in reality it can cause rough running.
DTC 42 can be a problem with the ICM due to heat soak. Is the “crappy” running all the time, or primarily when the car has been driven for a while and the engine gets hot? Intermittent problems are harder to find. See how fast the codes come back, and whether it seems that the engine starts running poorly as soon as you start it, or after it’s been running for a while.
Heres a update. I started the car today and hooked up the scanner 9495 program. It ran fine for the first 10min or so then it started sputtering and backfiring when I tried to give it gas. The ses light was on on the dash but the computer isn’t showing and dtc codes on my laptop while it’s hooked up and running and when I turn the car off and the ignition light is on. I’m at a loss right now I don’t know why it’s not showing me any codes.
