Throttle Surge
06-09-2019, 06:06 PM
#1
Registered Member
Thread Starter
Throttle Surge
Hey I have a 2008 G37 Sport. Randomly something will go wrong with the engine management, I've had it happen 0 times in a week or 4 times in a week...
The first sign is idle starts to rest at 800 rpm instead of 650 like normal. The throttle will surge randomly at low revs, whether you're in a gear or in neutral, and it can happen whether I'm on or off the gas. If I select first and slowly let the clutch out with my foot completely off gas pedal, the revs will drop a bit (of course) but then this surge happens and it jumps to ~1500 making it impossible to engage first like a normal person. I could also be like in third gear, going slow-ish (below 2000rpm), then let's say I put on 30% throttle. That's fine for a moment but then the car could give extra throttle for a few seconds as if I'm asking for 60% throttle, then it goes back to where I actually have the pedal position. Another example is first gear engaged, I'm going 4mph and put on the tiniest bit of throttle to crawl forward faster, the car will leap ahead as if I'm giving way more throttle.
It has been this way for months and pissing me off, and I haven't been able to reproduce for my mechanic so they won't do anything. I have absolutely no clue what causes the car to enter this mode. It truly seems random. Sometimes turning the car off/on gets rid of it...
I've reset the ECU (unplug battery overnight), done the throttle pedal position reset, throttle body relearn, and idle air relearn. These did not help the issue. Any thoughts on what the f is going on and what I should do???
The first sign is idle starts to rest at 800 rpm instead of 650 like normal. The throttle will surge randomly at low revs, whether you're in a gear or in neutral, and it can happen whether I'm on or off the gas. If I select first and slowly let the clutch out with my foot completely off gas pedal, the revs will drop a bit (of course) but then this surge happens and it jumps to ~1500 making it impossible to engage first like a normal person. I could also be like in third gear, going slow-ish (below 2000rpm), then let's say I put on 30% throttle. That's fine for a moment but then the car could give extra throttle for a few seconds as if I'm asking for 60% throttle, then it goes back to where I actually have the pedal position. Another example is first gear engaged, I'm going 4mph and put on the tiniest bit of throttle to crawl forward faster, the car will leap ahead as if I'm giving way more throttle.
It has been this way for months and pissing me off, and I haven't been able to reproduce for my mechanic so they won't do anything. I have absolutely no clue what causes the car to enter this mode. It truly seems random. Sometimes turning the car off/on gets rid of it...
I've reset the ECU (unplug battery overnight), done the throttle pedal position reset, throttle body relearn, and idle air relearn. These did not help the issue. Any thoughts on what the f is going on and what I should do???
06-10-2019, 01:14 PM
#5
I've been dealing with the same thing, and sometimes my engine almost dies on warm-starts. It's so random, and it doesn't always happen.
I've tried: MAF Sensor Cleaning, Replaced one upstream o2 Sensor (Helped a lot with response), Cleaned throttle bodies, Idle Re-Learn Procedure, Throttle Position Reset Procedure, Butterfly Throttle Body Reset Procedure
But the issue always comes back.
I've tried: MAF Sensor Cleaning, Replaced one upstream o2 Sensor (Helped a lot with response), Cleaned throttle bodies, Idle Re-Learn Procedure, Throttle Position Reset Procedure, Butterfly Throttle Body Reset Procedure
But the issue always comes back.
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