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1999 5.2L misses at idle, stumbles at +2,800 RPM's
2nd Gen Ram Tech1994-2001 Rams: This section is for TECHNICAL discussions only, that involve the 1994 through 2001 Rams. For any non-tech discussions, please direct your attention to the "General discussion/NON-tech" sub sections.
Okay, I broke down and took her to another dealer today. Now, before this, I replaced the MAP sensor, an Advance part, and the IAC motor, an O'Reiley part. My guy at the dealership said it was a fried #1 injector and a bad MAP sensor. He unplugged the injector, and for the ride home, aside from the miss, seemed better (figure that out.) A new injector and MAP sensor (both Mopar) will be here Wednesday. Updates then.
Okay, sorry for the delay. I installed the new injector and MAP sensor. It's not any better; in fact, maybe a little worse. I'm going bald over this. I took her to another shop yesterday (not a dealer). I was told they're good and bluntly honest. Results when I get them.
Its only on moderate to heavy throttle that it bucks and stumbles. Any thoughts?
Typical plenum leak, Like in my first post. The vac leak causes the pcm to have fits and drops out the ignition(misfire), Then it will fire at the wrong time causing a pop(backfire) through the intake under hard throttle. I know this because i watched it happen on mine before i knew about all the issues a leaking plenum can cause. Timing light on the coil wire proved this. Replace it with the Hughes kit and ran perfect afterwards.
Typical plenum leak, Like in my first post. The vac leak causes the pcm to have fits and drops out the ignition(misfire), Then it will fire at the wrong time causing a pop(backfire) through the intake under hard throttle. I know this because i watched it happen on mine before i knew about all the issues a leaking plenum can cause. Timing light on the coil wire proved this. Replace it with the Hughes kit and ran perfect afterwards.
Yeah, umm, I have the Hughes kit. Even replaced the gasket while I was in there. I got her back from the shop today. First, they said the first dealership incorrectly set the sync. They set it again and claimed her fixed. When she first fired up, she sounded great. Even worked better.... Until she warmed up. Then, back to her begrudging self. I did a U-turn back to the shop. The tech hooked into her and at first, it looked like the TPS, because even when he had her nearly redlined, it only showed 10%. But the head guy there said that the PCM was malfunctioning and reading it wrong. He said he tried to re-flash it but it wouldn't respond. I had one from another truck, same year, 5.9 motor, auto trans. He installed it and tried to flash it to my truck, but he said this one wouldn't re-flash, either. He left it installed and said to try it. Funny though, the "shutting off at idle" problem almost disappeared, although I still have little power and still can't exceed 3,000 RPM's if my foot is in it at all. He said something to the sort of "wouldn't hold it's programming". I can generally start from an idle, but she still almost wants to die from an idle if left that way long enough. My buddy from O'Reilley's said to expect that, because an auto trans has different timing than a manual. Does it sound like a bad PCM? And why would it go bad only after I jumped time?