High RPM misfire
08-20-2021, 11:34 AM
#46
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,825
Re: High RPM misfire
Is the engine running the same with the MAF as it did with speed-density?
Just to be clear, these are the problems you are having:
POST #25 - "atound 5 to 6000 it breaks up "
POST #27 - "it only starts to break up and pop like crazy at 5 to 6k then shift to third"
- "the last time i had it on the high way and sent it the rev limiter on the msd box was set to 5500rpm then it broke up. then i pulled over at a toll gate changed the rev limiter to 6500 and checked the codes and it still has a code 36 and at some point it did have a code 42 but it never came back,"
POST #31 - "top end 5k or 6k rpm breaking and popping then shifting."
POST #32 - "and it now just hesitates and idles low at like 600ish"
- "when it goes into drive its at 600 500rpm"
- "it starts right up after 3 seconds which is normal"
- "only thing is still the hesitation when i give it more gas it still hesitates at like 1500 2000rpm then it ups and goes. "
Now, the data logs - VERY CONFUSING
Two of them (first and second in your list) appear to be ROUGHLY the same set of data, from the period 14:00:09 to 14:17:05. The first one in your list is just missing the top couple rows, including the column titles. But, while the data is SIMILAR, it isn't exactly the same. For example in "Total; Scan Time" there is an 0.03-second difference in times. How did you end up with this situation? I have never seen this in 10+ years of looking at Scan9495 logs.
Then there's the third log in your list, and it apparently precedes the other two, since the time stamp is 13:38:28 to 13:56:34
What is the significance of the sequence between the two different logs (earlier and later). Is this two separate driving events, or did the engine shut off between the two?
These things take a lot of time and effort to review. Right now I have a major problem with my vision - I am two weeks out of surgery on my left eye, and while the vision has improved at a distance, it is still not good looking at things close range like staring at a computer screen. I can spend the time, but I don't want to spend it and find out that I should have looked at the first one or the third one..
Just to be clear, these are the problems you are having:
POST #25 - "atound 5 to 6000 it breaks up "
POST #27 - "it only starts to break up and pop like crazy at 5 to 6k then shift to third"
- "the last time i had it on the high way and sent it the rev limiter on the msd box was set to 5500rpm then it broke up. then i pulled over at a toll gate changed the rev limiter to 6500 and checked the codes and it still has a code 36 and at some point it did have a code 42 but it never came back,"
POST #31 - "top end 5k or 6k rpm breaking and popping then shifting."
POST #32 - "and it now just hesitates and idles low at like 600ish"
- "when it goes into drive its at 600 500rpm"
- "it starts right up after 3 seconds which is normal"
- "only thing is still the hesitation when i give it more gas it still hesitates at like 1500 2000rpm then it ups and goes. "
Now, the data logs - VERY CONFUSING
Two of them (first and second in your list) appear to be ROUGHLY the same set of data, from the period 14:00:09 to 14:17:05. The first one in your list is just missing the top couple rows, including the column titles. But, while the data is SIMILAR, it isn't exactly the same. For example in "Total; Scan Time" there is an 0.03-second difference in times. How did you end up with this situation? I have never seen this in 10+ years of looking at Scan9495 logs.
Then there's the third log in your list, and it apparently precedes the other two, since the time stamp is 13:38:28 to 13:56:34
What is the significance of the sequence between the two different logs (earlier and later). Is this two separate driving events, or did the engine shut off between the two?
These things take a lot of time and effort to review. Right now I have a major problem with my vision - I am two weeks out of surgery on my left eye, and while the vision has improved at a distance, it is still not good looking at things close range like staring at a computer screen. I can spend the time, but I don't want to spend it and find out that I should have looked at the first one or the third one..
08-20-2021, 03:06 PM
#47
Registered User
Join Date: Aug 2021
Posts: 21
Re: High RPM misfire
Is the engine running the same with the MAF as it did with speed-density?
Just to be clear, these are the problems you are having:
POST #25 - "atound 5 to 6000 it breaks up "
POST #27 - "it only starts to break up and pop like crazy at 5 to 6k then shift to third"
- "the last time i had it on the high way and sent it the rev limiter on the msd box was set to 5500rpm then it broke up. then i pulled over at a toll gate changed the rev limiter to 6500 and checked the codes and it still has a code 36 and at some point it did have a code 42 but it never came back,"
POST #31 - "top end 5k or 6k rpm breaking and popping then shifting."
POST #32 - "and it now just hesitates and idles low at like 600ish"
- "when it goes into drive its at 600 500rpm"
- "it starts right up after 3 seconds which is normal"
- "only thing is still the hesitation when i give it more gas it still hesitates at like 1500 2000rpm then it ups and goes. "
Now, the data logs - VERY CONFUSING
Two of them (first and second in your list) appear to be ROUGHLY the same set of data, from the period 14:00:09 to 14:17:05. The first one in your list is just missing the top couple rows, including the column titles. But, while the data is SIMILAR, it isn't exactly the same. For example in "Total; Scan Time" there is an 0.03-second difference in times. How did you end up with this situation? I have never seen this in 10+ years of looking at Scan9495 logs.
Then there's the third log in your list, and it apparently precedes the other two, since the time stamp is 13:38:28 to 13:56:34
What is the significance of the sequence between the two different logs (earlier and later). Is this two separate driving events, or did the engine shut off between the two?
These things take a lot of time and effort to review. Right now I have a major problem with my vision - I am two weeks out of surgery on my left eye, and while the vision has improved at a distance, it is still not good looking at things close range like staring at a computer screen. I can spend the time, but I don't want to spend it and find out that I should have looked at the first one or the third one..
Just to be clear, these are the problems you are having:
POST #25 - "atound 5 to 6000 it breaks up "
POST #27 - "it only starts to break up and pop like crazy at 5 to 6k then shift to third"
- "the last time i had it on the high way and sent it the rev limiter on the msd box was set to 5500rpm then it broke up. then i pulled over at a toll gate changed the rev limiter to 6500 and checked the codes and it still has a code 36 and at some point it did have a code 42 but it never came back,"
POST #31 - "top end 5k or 6k rpm breaking and popping then shifting."
POST #32 - "and it now just hesitates and idles low at like 600ish"
- "when it goes into drive its at 600 500rpm"
- "it starts right up after 3 seconds which is normal"
- "only thing is still the hesitation when i give it more gas it still hesitates at like 1500 2000rpm then it ups and goes. "
Now, the data logs - VERY CONFUSING
Two of them (first and second in your list) appear to be ROUGHLY the same set of data, from the period 14:00:09 to 14:17:05. The first one in your list is just missing the top couple rows, including the column titles. But, while the data is SIMILAR, it isn't exactly the same. For example in "Total; Scan Time" there is an 0.03-second difference in times. How did you end up with this situation? I have never seen this in 10+ years of looking at Scan9495 logs.
Then there's the third log in your list, and it apparently precedes the other two, since the time stamp is 13:38:28 to 13:56:34
What is the significance of the sequence between the two different logs (earlier and later). Is this two separate driving events, or did the engine shut off between the two?
These things take a lot of time and effort to review. Right now I have a major problem with my vision - I am two weeks out of surgery on my left eye, and while the vision has improved at a distance, it is still not good looking at things close range like staring at a computer screen. I can spend the time, but I don't want to spend it and find out that I should have looked at the first one or the third one..
the breaking up at high rpm was because the rev limiter bc of the box was set to 5500 and the ****s were not complying that eas my fault. but i do notice at high rpm if i get back on it it doesnt want to add fuel or something because the rpms hesitate and it tried to fall on its face but it catches itself and gets back in the powerband ...all it does now completely since getting a new pcm and resetting to a factory tune. it seems it doesnt get enough fuel at low rpm or any rpm if i just tap the theottle to normally drive i have to still loghtly presses it get it to not want to try to fall on itself. and its still throwing the high res pulse issue and i think at this point it could probably be my wiring or something and i doubt if i change my spark plugs it wont make a difference but its worth a try...the one that was different i forgot that the 1st wop but different was another wop pull to see if it was the same so apologies on that, as for the low rpm if i even tap it, it wants to die and breakup and hesitation and hiccup. so i have no clue i have tried to put a volt meter on it and all the voltages going to the opti and icm are fine. so i have no clue whatelse other then engine parts like spark plugs or wiring or something else. but the one that was called the drive did that show anything that was out of the ordinary?
Last edited by rustv8; 08-20-2021 at 03:12 PM.
08-20-2021, 04:15 PM
#48
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,825
Re: High RPM misfire
I didn’t look at them in detail because I wanted to know why there were three files and what the differences were. Also wanted to know all mods because that can affect the way some of the data should look. I'll get to them in the next few days. I have two files open for others that I am in the middle of.
08-21-2021, 12:46 AM
#49
Prominent Member
Join Date: Jul 2010
Location: Born on the Florida West Coast, now where can I retire?
Posts: 1,505
Re: High RPM misfire
rustv8: Just a tip: Fred (genius) and I (just a bit over average) are old engineers and we really appreciate accurate and concise replies. Try to focus on what is asked and temper your answers. Getting to the point quickly can make all the difference in diagnosing a difficult problem ;-)
08-25-2021, 04:37 PM
#50
Administrator
Join Date: Nov 1998
Location: Hell was full so they sent me to NJ
Posts: 70,825
Re: High RPM misfire
No sure why this us so difficult. Started with the first log in your list.
- was not from a cold start as requested. 183-degF coolant at start.
- appears you played with the throttle in (possibly) 3 places in open loop, which I asked not be done Two instances are very low throttle position %, which might have been a glitch in the TPS volts, and you weren't actually touching the throttle. But RPM did increase, so it appears throttle actually moved.
- appears that on line 282 the data logging stopped, and reset to "0" scan time. But the engine was still running. Logging stopped at 53 seconds engine run time, and didn't restart until more than 6 minutes later, at 430-seconds run time.
I'm going to move on to the third file in the list. Hopefully that conforms to what I want to see, and didn't suffer a disconnection of the logging.system.
- was not from a cold start as requested. 183-degF coolant at start.
- appears you played with the throttle in (possibly) 3 places in open loop, which I asked not be done Two instances are very low throttle position %, which might have been a glitch in the TPS volts, and you weren't actually touching the throttle. But RPM did increase, so it appears throttle actually moved.
- appears that on line 282 the data logging stopped, and reset to "0" scan time. But the engine was still running. Logging stopped at 53 seconds engine run time, and didn't restart until more than 6 minutes later, at 430-seconds run time.
I'm going to move on to the third file in the list. Hopefully that conforms to what I want to see, and didn't suffer a disconnection of the logging.system.
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