hesitation M-tune.
12-04-2011, 08:09 PM
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hesitation M-tune.
I have not used my car for a few months and I started it up and it bogs and hesitates on acceleration, when it's cold. Once the engine warms up it no longer does this. I am stumped, need help.
Thanks.
Thanks.
12-04-2011, 08:20 PM
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Yes - this has to do with the MAP sensor error detection, and the colder weather.
I am just about to send out an update to fix this. (finishing the software now)
I am just about to send out an update to fix this. (finishing the software now)
12-04-2011, 09:51 PM
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Joshua, does the update address anything in the upper rev/boost ranges? Now that our weather is generally below 40-50 degrees in the mornings, I've noticed my car running vey lean at 17-18 psi on e85 and it's got serious hesitation/missing when it happens... I'm taking about numbers like 14-15-16 AFR. I backed my boost down to 16 psi and everything is back to normal.
12-04-2011, 09:55 PM
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Matt - something might not be keeping up in your fuel delivery.. What fuel pump are you using?
Also, mis-firing will show up as lean, typically. What plugs & gap are you using? E85 is harder to light-off than gas, combined with higher boost pressure and cold weather - your ignition system must be in good condition.
Send me an email with what you are seeing and any logs.
Also, mis-firing will show up as lean, typically. What plugs & gap are you using? E85 is harder to light-off than gas, combined with higher boost pressure and cold weather - your ignition system must be in good condition.
Send me an email with what you are seeing and any logs.
12-04-2011, 10:42 PM
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I've got a newly installed Bosch HV pump from LR along with new screen and filter. Hopefully that's enough pump for what I suspect is under 350 rwhp. Ignition is all new too with properly gapped Bosch copper plugs. Unfortunatly no data logging. I'll shoot you an email so we can discuss offline.
12-09-2011, 05:01 PM
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Joshua & I discussed vial email and he gave me some tips, so I wanted to add the results here for the record...
Based on Joshua's suggestion of colder plugs gapped tighter, I did the easy thing first and gapped my stock temp range plugs at .025" (they were .032"). After gapping them tighter, I was able to turn the boost back up to 19-20 PSI and the car screams again!
The current plugs are Bosch Copper WR7DC, and I will probably swap them out with a WR5DC or NGK BRP7ES per Joshua's recommendation.
Based on Joshua's suggestion of colder plugs gapped tighter, I did the easy thing first and gapped my stock temp range plugs at .025" (they were .032"). After gapping them tighter, I was able to turn the boost back up to 19-20 PSI and the car screams again!
The current plugs are Bosch Copper WR7DC, and I will probably swap them out with a WR5DC or NGK BRP7ES per Joshua's recommendation.
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12-27-2011, 08:25 PM
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I installed the latest chip today and I'm happy with the results so far.
The good: While it was warm this afternoon by the time I went for a drive after the install, I detected no hesitation. I'll know a lot more in the morning when it's 40-ish and I head to work at 6:30AM.
The bad: I've noticed some VERY erratic RPM's at idle just during the two quick trips I made after the install. The first issue I noticed in my driveway when backing out of the garage, and I let the car idle for a few minutes... it was up to temp, and I drove a few feet toward my garage door so I could back up and turn around and when I pushed the clutch in, the car dropped to idle, then did 3 or 4 quick surges to 2,000, 3,000, and 3,500 rpm, then stayed around 2,000 rpm. I immediately turned the car off because it was acting so erratic, I thought it might redline itself. After I restarted, the problem went away. Later in the evening, sitting at a red light with the clutch in and no throttle pressure, the idle bounced quickly between 1,500 and 2,000 rpm, then settled at around 1,200. I could tell it was the idle control servo because of how quickly it was surging up and down, but this is a new problem just this afternoon since the new chip.
The unexpected (more good): I had been experiencing some very strange throttle cuts when transitioning from part throttle with minimal boost (0-3 ish PSI) to off throttle... you know... just light acceleration and deceleration you would expect on a crowded highway during rush hour. It was like the recirc valve was sticking or opening too soon causing a sudden drop in RPM while still in gear, it made for frequent abrupt deceleration moments. The good thing I've noticed so far with the updated chip is that this problem appears to have gone away. I tried several times to replicate the old issue, but I couldn't make it happen.
I'll know a lot more about all of this stuff tomorrow after my typical 91 mile round-trip to work on familiar roads. If the odd idle hunting problem continues, I'll drop Joshua an email so we can discuss what might be the cause.
The good: While it was warm this afternoon by the time I went for a drive after the install, I detected no hesitation. I'll know a lot more in the morning when it's 40-ish and I head to work at 6:30AM.
The bad: I've noticed some VERY erratic RPM's at idle just during the two quick trips I made after the install. The first issue I noticed in my driveway when backing out of the garage, and I let the car idle for a few minutes... it was up to temp, and I drove a few feet toward my garage door so I could back up and turn around and when I pushed the clutch in, the car dropped to idle, then did 3 or 4 quick surges to 2,000, 3,000, and 3,500 rpm, then stayed around 2,000 rpm. I immediately turned the car off because it was acting so erratic, I thought it might redline itself. After I restarted, the problem went away. Later in the evening, sitting at a red light with the clutch in and no throttle pressure, the idle bounced quickly between 1,500 and 2,000 rpm, then settled at around 1,200. I could tell it was the idle control servo because of how quickly it was surging up and down, but this is a new problem just this afternoon since the new chip.
The unexpected (more good): I had been experiencing some very strange throttle cuts when transitioning from part throttle with minimal boost (0-3 ish PSI) to off throttle... you know... just light acceleration and deceleration you would expect on a crowded highway during rush hour. It was like the recirc valve was sticking or opening too soon causing a sudden drop in RPM while still in gear, it made for frequent abrupt deceleration moments. The good thing I've noticed so far with the updated chip is that this problem appears to have gone away. I tried several times to replicate the old issue, but I couldn't make it happen.
I'll know a lot more about all of this stuff tomorrow after my typical 91 mile round-trip to work on familiar roads. If the odd idle hunting problem continues, I'll drop Joshua an email so we can discuss what might be the cause.