5k rpm studder with UTEC
Dec 10, 2004, 11:13 AM
#31
Originally Posted by Imprezd
Jack, if you can feel the transition it's because you still need to smooth your transition point. Most of the time you can see it immediately, you’ll have a large IDC jump + or -. It's pretty simple to smooth it out.
Thanks,
Jermaine~
Thanks,
Jermaine~
Dec 10, 2004, 11:17 AM
#32
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If you are tuning map vs. rpm it should be fairly easy since you are sweeping through load sites alot smoother than maf frequency. Also you will have less of an irratic load site jump if you are tuning map based with a max of about 25-28 psi.
Thanks,
Jermaine~
Thanks,
Jermaine~
Dec 10, 2004, 11:21 AM
#33
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Oh yeah not to mention, I sent you an email to Jermaine, but would that crimped wire cause the fuel/timing to go haywire while tuning. I couldnt get tuned for more than 10.6 AFR or it would knock. I need to also explore other options that would eliminate any possible reason for the knocking at like 10.8 AFR. Not sure if there was anything else in the UTEC like timing or whatever that had the possibility of being damaged but curious to see if there are other things like O2 or knock sensors that could be culprits. I hear the knock sensor either works or doesnt work. If it works then its the ECU that percieves whats knock and not that the knock sensor is over sensitive like a microphone with feedback. Is that right? I was also thinking the front o2 may be bad. I dont know how it works but my theory was that the ECU may be reading lean conditions and then dumping fuel making it virtually impossible to lean it out. Does that make sense?
Dec 10, 2004, 11:32 AM
#34
Originally Posted by Imprezd
If you are tuning map vs. rpm it should be fairly easy since you are sweeping through load sites alot smoother than maf frequency. Also you will have less of an irratic load site jump if you are tuning map based with a max of about 25-28 psi.
Thanks,
Jermaine~
Thanks,
Jermaine~
Dec 10, 2004, 11:35 AM
#35
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Originally Posted by TampaTurbo
Oh yeah not to mention, I sent you an email to Jermaine, but would that crimped wire cause the fuel/timing to go haywire while tuning. I couldnt get tuned for more than 10.6 AFR or it would knock. I need to also explore other options that would eliminate any possible reason for the knocking at like 10.8 AFR. Not sure if there was anything else in the UTEC like timing or whatever that had the possibility of being damaged but curious to see if there are other things like O2 or knock sensors that could be culprits. I hear the knock sensor either works or doesnt work. If it works then its the ECU that percieves whats knock and not that the knock sensor is over sensitive like a microphone with feedback. Is that right? I was also thinking the front o2 may be bad. I dont know how it works but my theory was that the ECU may be reading lean conditions and then dumping fuel making it virtually impossible to lean it out. Does that make sense?
Thanks,
Jermaine~
Dec 10, 2004, 11:50 AM
#36
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Originally Posted by Imprezd
Honestly, I would attribute a lot of inconsistency's and things ecu related to be due to the fact you had a wire from your stock ecu grounded out. I am frankly surprised you didn't fry your stock ecu. If other things are damaged, that would be my number 1 suspect. Under load your stock ecu has no ability to add fuel or subtract fuel. Whatever you had grounded caused all types of headaches, end of story. I truly doubt your front 02 is bad. Unless your car is have a hard time idling and drive ability just sucks. That's what the front 02 is there for.
Thanks,
Jermaine~
Thanks,
Jermaine~
Jan 6, 2005, 06:13 PM
#37
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i know this thread is a little old, but im have a close problem to this. i just got back from harman motive in socal. the tuner was having problems with a studder at 4000rpms. he wasn't able to tune above 11.0. so my numbers were bad and the car has a bad studder/hicup. the tuner says it may be the delphi injectors or the UTEC. i was told that these 780cc are horrible with the utec. could my utec be faulty? any info would help. thanks justin
Jan 6, 2005, 07:27 PM
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OLF was on. i have the dyno sheet, but i wont be able to get it online till tomorrow. im going to install some stock injectors tomorrow to see if thats the problem.
Jan 6, 2005, 08:00 PM
#44
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it could possibly be fuel cut. Not to mention the larger the injectors makes it more difficult to tune with. At least with the UTEC. Dont get me wrong, it can be tuned for larger injectors but it takes more time to fool with. Your injectors will either work or they wont. I assume they are new. If you had a bad injector, I would think at all rpms your car would be fubar. Delphi's are like denso type injectors so that should work well. I have the RC eng saturated injectors and are designed differently. If you were here we could blow through the possibilities