Tweet
Hello all! I'm new to this forum, but am having some difficulties with my firebird and was wondering if anyone could lead me in the right direction! (sorry for the long post, but trying to be descriptive!)
1996 firebird V6 – 160000 miles. I recently developed an issue with sputtering/missing out upon acceleration under load. The car starts fine, idles fine (around 750 rpm), and doesn’t miss a beat if running it in park with no load. When driving the car, it runs perfect and has full power with no “missing out” for about 5-10 minutes up until it reaches close to operating temperature. After the engine is warm, I can lightly accelerate up to any speed with no hesitation whatsoever. When I try to really step on it, or hit the pedal far enough to kick it down a gear and rev the RPM’s up, the car will sputter/hesitate/miss out/ whatever you wanna call it. Sometimes it will come out of it enough to continue revving, but sometimes not. It is especially bad if it is lugging in overdrive and then I try to kick the pedal down. If I let off the gas and accelerate easy again, no problems.
Had similar issues last year and pulled my coils off and checked the resistance of each, finding one that check wide open on the high output leads, therefore, obvious/easy fix. Now I have one aftermarket cheapie coil, and two original to the car with 160,000 miles on them. I assumed I had a bad coil pack again based upon the description of my problem above.
I pulled all three coils and checked them with an ohmmeter again…both factory coils check .6 ohms on the primary side, and 5100 ohms on the high side (both within spec). The aftermarket coil that I put on last year checked .9 ohms on the primary, and around 10,000 ohms on the high side (also in spec). I pulled and rechecked again after they were nice and hot after driving around for awhile and they checked the same as before. So…I’m ruling out a bad coil pack.
I’ve had a check engine light for a while due to the EVAP system, but I went and had my codes scanned and got a P1406-EGR pintle position error. I pulled the EGR valve to clean it, but it wasn’t really carboned up or anything, and the pintle moved nice and freely throughout it’s entire range. I cleaned it and made sure that the lines to the intake and the header were clear as well…no change in the condition. I’ve also just unplugged it completely and it ran exactly the same. Anyway, my experience with EGR valves is that they usually stick open and cause rough idle and not affect performance in normal driving.
I’ve pulled and cleaned the MAF sensor to no change, and also ran the car with the MAF unplugged with no change.
I’ve pulled/cleaned the PCV valve with no change.
I've unplugged every sensor with the exception of the o2 sensors hoping it kept the car in an "open loop" situation and still has the sputtering. The only sensor that changed anything was the TPS sensor which made the transmission not shift from first.
Ive sprayed water around anywhere that I thought there could be a vacuum leak but haven’t found anything including around the intake.
I’ve tried finding an arcing plug wire in the dark but nothing is obvious.
Do any of you experts out there have any suggestions based upon the symptoms, and the things I have already done? My dad told me last night it sounds like and “open” plug wire and told me to pull each wire and check the resistance with the Ohmmeter, saying a bad one should have almost no resistance. To me, this problem has to be electrical, either a plug, a non-obvious plug wire, or a sensor somewhere, but I would think it would throw a code of some sort??? I am not getting any misfire codes. What about the ICM? Can that be checked with a meter? I know there are probably 25 different things that could cause this condition, but looking for the most common. To me, the key has to be that the car runs perfect until it reaches 180 degrees on the temp gauge!
Any help or suggestions would be appreciated!
1996 firebird V6 – 160000 miles. I recently developed an issue with sputtering/missing out upon acceleration under load. The car starts fine, idles fine (around 750 rpm), and doesn’t miss a beat if running it in park with no load. When driving the car, it runs perfect and has full power with no “missing out” for about 5-10 minutes up until it reaches close to operating temperature. After the engine is warm, I can lightly accelerate up to any speed with no hesitation whatsoever. When I try to really step on it, or hit the pedal far enough to kick it down a gear and rev the RPM’s up, the car will sputter/hesitate/miss out/ whatever you wanna call it. Sometimes it will come out of it enough to continue revving, but sometimes not. It is especially bad if it is lugging in overdrive and then I try to kick the pedal down. If I let off the gas and accelerate easy again, no problems.
Had similar issues last year and pulled my coils off and checked the resistance of each, finding one that check wide open on the high output leads, therefore, obvious/easy fix. Now I have one aftermarket cheapie coil, and two original to the car with 160,000 miles on them. I assumed I had a bad coil pack again based upon the description of my problem above.
I pulled all three coils and checked them with an ohmmeter again…both factory coils check .6 ohms on the primary side, and 5100 ohms on the high side (both within spec). The aftermarket coil that I put on last year checked .9 ohms on the primary, and around 10,000 ohms on the high side (also in spec). I pulled and rechecked again after they were nice and hot after driving around for awhile and they checked the same as before. So…I’m ruling out a bad coil pack.
I’ve had a check engine light for a while due to the EVAP system, but I went and had my codes scanned and got a P1406-EGR pintle position error. I pulled the EGR valve to clean it, but it wasn’t really carboned up or anything, and the pintle moved nice and freely throughout it’s entire range. I cleaned it and made sure that the lines to the intake and the header were clear as well…no change in the condition. I’ve also just unplugged it completely and it ran exactly the same. Anyway, my experience with EGR valves is that they usually stick open and cause rough idle and not affect performance in normal driving.
I’ve pulled and cleaned the MAF sensor to no change, and also ran the car with the MAF unplugged with no change.
I’ve pulled/cleaned the PCV valve with no change.
I've unplugged every sensor with the exception of the o2 sensors hoping it kept the car in an "open loop" situation and still has the sputtering. The only sensor that changed anything was the TPS sensor which made the transmission not shift from first.
Ive sprayed water around anywhere that I thought there could be a vacuum leak but haven’t found anything including around the intake.
I’ve tried finding an arcing plug wire in the dark but nothing is obvious.
Do any of you experts out there have any suggestions based upon the symptoms, and the things I have already done? My dad told me last night it sounds like and “open” plug wire and told me to pull each wire and check the resistance with the Ohmmeter, saying a bad one should have almost no resistance. To me, this problem has to be electrical, either a plug, a non-obvious plug wire, or a sensor somewhere, but I would think it would throw a code of some sort??? I am not getting any misfire codes. What about the ICM? Can that be checked with a meter? I know there are probably 25 different things that could cause this condition, but looking for the most common. To me, the key has to be that the car runs perfect until it reaches 180 degrees on the temp gauge!
Any help or suggestions would be appreciated!
Comment