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Discussion Starter #1
I've been trying to figure this out for over a month on my own, but have decided i need help. I've read other topics similar to my problems, but symptoms don't quite match up. I have a 1997 SS, LT1.
Mods: Procharger P1SC, 4.10, straight exhaust, MSD ignition, upgraded fuel system.
Problem: Runs great when initially started, once hits 160/180 has rough idle, almost stalling, backfires. If i give it gas it runs fine. No loss of power evident. It starts right up every time. When it starts running erraticaly smells rich, i can taste the fuel.
Done so far:
1.Tested MAF: seems fine, but i'm no expert, maybe i screwed up the test. i checked the frequency and it changed linearly with acceleration.
2. Replaced ICM and Coil: no change noted.
3. Replaced coolant temperature sensor yesterday: before it would act up after 5 minutes, now i can drive it for about 15 minutes before it starts running eratically. I was really happy for about 10 minutes.
4. other considerations: Optispark, plugs, wires, and all mods done by reputable shop (SDCE in Warwick, RI), done in 1 phases, Aug of last year, and Jan of this year. So i'm kind of ruling out that part of the ignition system
5. Leaves me with MAP, PCM, ECM. Some sensor that picks up in open loop?
Any ideas, thoughts, prayers?
thanks in advance
 

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Have you put it on a scanner to check for codes? Not all codes light the ses, including the 3 ignition biggies. Also have a scanner that does running sensor scans. The data you get can go a long way towards troubleshooting your problems. Next, don't be a parts changer, even if you get a code, that code can be caused by wiring to pcm, power source, ground for pcm, ground for sensors, bad connection, etc. If you pm me with your e-mail address, I'll send you a pdf file of "sensor readings and what they mean. That should help you understand what's going on.
 

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Discussion Starter #3
I took it to a shop when the SES light came on(over month ago), and it only showed p3000, random miss, nothing else. They cleared it, and i have not gotten a light since, but i can go back to them to see if any other codes are stored. I'll pm you with my email, Thanks
 

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I've been trying to figure this out for over a month on my own, but have decided i need help. I've read other topics similar to my problems, but symptoms don't quite match up. I have a 1997 SS, LT1.
Mods: Procharger P1SC, 4.10, straight exhaust, MSD ignition, upgraded fuel system.
Problem: Runs great when initially started, once hits 160/180 has rough idle, almost stalling, backfires. If i give it gas it runs fine. No loss of power evident. It starts right up every time. When it starts running erraticaly smells rich, i can taste the fuel.
Done so far:
1.Tested MAF: seems fine, but i'm no expert, maybe i screwed up the test. i checked the frequency and it changed linearly with acceleration.
2. Replaced ICM and Coil: no change noted.
3. Replaced coolant temperature sensor yesterday: before it would act up after 5 minutes, now i can drive it for about 15 minutes before it starts running eratically. I was really happy for about 10 minutes.
4. other considerations: Optispark, plugs, wires, and all mods done by reputable shop (SDCE in Warwick, RI), done in 1 phases, Aug of last year, and Jan of this year. So i'm kind of ruling out that part of the ignition system
5. Leaves me with MAP, PCM, ECM. Some sensor that picks up in open loop?
Any ideas, thoughts, prayers?
thanks in advance
Could be injectors hanging up when they get warm. Try listening to each injector with an automotive stethoscpe when cold then when hot. There should be a distinct metallic clicking sound and they all should sound the same. It could also be a weak igintion coil which get's worse when it heats up. Without some test equipment or a osccilloscope to read voltage and current wave forms it can be a nightmare diagnosing electronic problems.
 
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