1st gear part throttle = lurching
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1st gear part throttle = lurching
Guys I'm having a problem hoping you can help me with which I'm guessing is either ignition or fuel related but haven't ruled out transmission or sc clutch.
So coming out of a stop part throttle in 1st the car seems to begin lurching violently at mid-high rpms. Think of coming on and of the accelerator rapidly, one second there's heaps of power then not so much then heaps then not so much ... Etc. It goes on and off in .5s intervals. If I plant the accelerator the car powers out of the lurching. This only seems to happen in 1st gear.
I thought it was esp engaging at first but the problem persists even with esp disabled. It's a pain when going around a slow corner, feathering the throttle to maintain rpms just before you power out.
Any ideas?
So coming out of a stop part throttle in 1st the car seems to begin lurching violently at mid-high rpms. Think of coming on and of the accelerator rapidly, one second there's heaps of power then not so much then heaps then not so much ... Etc. It goes on and off in .5s intervals. If I plant the accelerator the car powers out of the lurching. This only seems to happen in 1st gear.
I thought it was esp engaging at first but the problem persists even with esp disabled. It's a pain when going around a slow corner, feathering the throttle to maintain rpms just before you power out.
Any ideas?
#2
my 32amg also lurches ahead but not to the same extent as yours does. From park, I put my foot on the gas pedal and nothing happens for a second or so, then it decides to lurch slightly. I've been living with it for some time, but have noticed that it doesn't seem to happen when I have it on the "w" mode. It mostly does it in "s" mode and cold start. After reading and researching, I tried one thing which seemed to help a bit, but I'm not sure if it was just wishful thinking. What I did was get in car, put key in ignition, turn it to the second position (engine off), then put foot on gas pedal for 30 secs, then turn key to off, wait 5 seconds, and start engine as per usual. Like I said, not sure if it was wishful thinking because it did seem to help the first couple of outings after that, but now it's doing it again. It'll be good to hear what others may say to help you out.
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my 32amg also lurches ahead but not to the same extent as yours does. From park, I put my foot on the gas pedal and nothing happens for a second or so, then it decides to lurch slightly. I've been living with it for some time, but have noticed that it doesn't seem to happen when I have it on the "w" mode. It mostly does it in "s" mode and cold start. After reading and researching, I tried one thing which seemed to help a bit, but I'm not sure if it was just wishful thinking. What I did was get in car, put key in ignition, turn it to the second position (engine off), then put foot on gas pedal for 30 secs, then turn key to off, wait 5 seconds, and start engine as per usual. Like I said, not sure if it was wishful thinking because it did seem to help the first couple of outings after that, but now it's doing it again. It'll be good to hear what others may say to help you out.
What you performed was a ecu reset which clears all the transmission adaptations... Resulting in a more responsive transmission. I'm guessing because of this, you power past the lockup/jerk which only seems to manifest itself at part throttle under alight load. Over time you transmission will relearn your driving pattern and shifts will get lazy again, especially if you drive in heavy traffic... Which will likely see the jerk become more noticeable again.
And yes correct my issue is different, it is a pulsating lack of power as if the sc is disengaging and then reengaging again rapidly. I'm going to regap the sc pulley as it's currently hard up against the clutch (can't even get the smallest feeler gauge in) and replace all the spark wires (needs to be done anyway). See how I go.
Last edited by crembz; 11-16-2014 at 08:32 PM.
#4
From your description I'm guessing you have the transmission jerk which every c32 owner seems to have, caused by late/rough lockup of the torque converter. I swapped out the torque converter pwm solenoid as suggested by a few ppl here and it cleaned up the problem heaps. The solenoid is pretty cheap, but you'll need to factor labor and trans fluid into the fix.
What you performed was a ecu reset which clears all the transmission adaptations... Resulting in a more responsive transmission. I'm guessing because of this, you power past the lockup/jerk which only seems to manifest itself at part throttle under alight load. Over time you transmission will relearn your driving pattern and shifts will get lazy again, especially if you drive in heavy traffic... Which will likely see the jerk become more noticeable again.
And yes correct my issue is different, it is a pulsating lack of power as if the sc is disengaging and then reengaging again rapidly. I'm going to regap the sc pulley as it's currently hard up against the clutch (can't even get the smallest feeler gauge in) and replace all the spark wires (needs to be done anyway). See how I go.
What you performed was a ecu reset which clears all the transmission adaptations... Resulting in a more responsive transmission. I'm guessing because of this, you power past the lockup/jerk which only seems to manifest itself at part throttle under alight load. Over time you transmission will relearn your driving pattern and shifts will get lazy again, especially if you drive in heavy traffic... Which will likely see the jerk become more noticeable again.
And yes correct my issue is different, it is a pulsating lack of power as if the sc is disengaging and then reengaging again rapidly. I'm going to regap the sc pulley as it's currently hard up against the clutch (can't even get the smallest feeler gauge in) and replace all the spark wires (needs to be done anyway). See how I go.
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I'm just getting stock bosch wires and doing the regap. Funny you should mention the tensioner, I've been almost convinced mine is getting slack, my indie insists it's fine but I'm also getting a rapping sound from inside the cabin coming from the same side as the tensioner. If the tensioner is going bad it could explain both symptoms.
#7
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Everything in this thread points to the PWM solenoid in the valve body; chased the TC jerk in mine for years: tranny flush, replaced valve body conductor plate, ecu resets - replacing that solenoid was without doubt the root-cause solution. Mine shifts perfectly smoothly now, except when starting cold and the outside temp is below say 25F and then I have an issue with shifting down from 2nd to 1st until the car warms up a little. Having the shift solenoids (3 of them) in the valve body replaced over the holidays to hopefully eliminate this.
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#8
No its not the same. Its almost like the car is misfiring. And it may actually be. It doesn't throw codes though. It doesn't do it until your like 40% on the throttle. Then it starts bucking or misfiring or belt slipping. I haven't figured it out yet as I have enough time with holidays
#9
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Sounds to me like the throttle body. Have someone check your codes.
I have a code reader too, but there's hidden stored codes that my mechanic was able to read. My code reader didn't see them.
I have a code reader too, but there's hidden stored codes that my mechanic was able to read. My code reader didn't see them.
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Thanks mate I'll ask my indie to pull the codes next time I'm down. I can easily replicate the symptom now, part throttle to around 4k rpm in 1st or 2nd and the suddenly go to 80% throttle. Funny thing is if I got wot it seems to pull through without lurching.