HELP! - Scan Results for L36 w/ cam, high compression
#11
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I don't think it will recover fully on it'* own. You're out of the limits of the PCM. Send me your raw data or a spreadsheet to william dot wren at gmail dot com
I'm suffering from some VERY similar symptoms after my top end work and have done alot of thinking, data collecting, and guessing. My mind is in the right frame for this one. I just need to jumble your data into some custom graphs to 'see' a trend or problem.
I'm suffering from some VERY similar symptoms after my top end work and have done alot of thinking, data collecting, and guessing. My mind is in the right frame for this one. I just need to jumble your data into some custom graphs to 'see' a trend or problem.
#13
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NOW you send it. Ben, you PITA.
I've got it, but I'm crashing for the night. I'll take some time on HP'* dime (that rhymes) tomorrow and crunch some data. I'm looking for a pattern or trend, but the IA GP guys are probably on the right track.
It'* odd that the problem is only at the lower rpm'* though. That makes me think exhaust leak.
I've got it, but I'm crashing for the night. I'll take some time on HP'* dime (that rhymes) tomorrow and crunch some data. I'm looking for a pattern or trend, but the IA GP guys are probably on the right track.
It'* odd that the problem is only at the lower rpm'* though. That makes me think exhaust leak.
#14
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I'm with 98 TGP TOY on your fueling issue. And you should really get something to adjust the fueling on the fly. The mini-afc 2.0/1/2 is great for this in my opinion. Once you get your LTFT'* as close to zero as possible, you can give your afc values to a programer and eventually you can get rid of the mini-afc. I doubt any programmer would be able to nail the a/f teh first time around.
Another thing about the a/f. At idle, you should be running a little lean. This is due to the increased valve overlap. Fresh air will be pulled into the cylinder and some will actually make it into the exhaust. Once your O2 sees this, it thinks your running lean but your actually not. So a little lean at idle is ok (slightly positive LTFT'*) but everywhere else your LTFT'* should be close to zero.
Another thing 98 TGP TOY said is that it'* ok to but in the Intense pcm with the advanced timing but I think he said this because it wasn't mentioned that you milled your heads .040" in that thread.
Another thing about the a/f. At idle, you should be running a little lean. This is due to the increased valve overlap. Fresh air will be pulled into the cylinder and some will actually make it into the exhaust. Once your O2 sees this, it thinks your running lean but your actually not. So a little lean at idle is ok (slightly positive LTFT'*) but everywhere else your LTFT'* should be close to zero.
Another thing 98 TGP TOY said is that it'* ok to but in the Intense pcm with the advanced timing but I think he said this because it wasn't mentioned that you milled your heads .040" in that thread.
#15
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Originally Posted by willwren
It'* odd that the problem is only at the lower rpm'* though. That makes me think exhaust leak.
So basically I had ruled out the possibility of exhaust issues. It seems that an extreme lean condition at part throttle would also be responsible for KR, wouldn't it? I'm looking into the possibility of a full-on dyno tune for this car, so maybe I'll be able to tell you whether fueling is enough to kill this KR. Keep coming at me with ideas, though! I definitely appreciate it!!
#16
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Originally Posted by big_news_1
It seems that an extreme lean condition at part throttle would also be responsible for KR, wouldn't it?
When you say full on dyno tune, what are you going to tune with?
#17
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Good question, Mike. Here'* the situation.
I spoke with a shop in Des Moines, IA called Midstate Machine. They have a chassis dyno, but it turns out they do NOT have tuning capability (the guy said I would have to go out of state to find a shop that can dyno tune the car :?). However, they can provide me with a complete fuel curve for the car, along with the traditional horsepower and torque curves for $50. I'm not sure if a fuel curve would provide me with the data I need to get a proper tune from Intense. What do you guys think?
Edited for unnecessary whining
I spoke with a shop in Des Moines, IA called Midstate Machine. They have a chassis dyno, but it turns out they do NOT have tuning capability (the guy said I would have to go out of state to find a shop that can dyno tune the car :?). However, they can provide me with a complete fuel curve for the car, along with the traditional horsepower and torque curves for $50. I'm not sure if a fuel curve would provide me with the data I need to get a proper tune from Intense. What do you guys think?
Edited for unnecessary whining
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Ben I really think that you shoud get a mini-afc 2.0+. You can use that to tune on the dyno. They are really not that hard to use and I could help explain it if you want.
#19
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Yeah, that doesn't sound like a bad idea. Like the guys over at IACGP were saying, if I had an AFC I would be able to dial in the fuel trims, then take the numbers from the AFC and have them programmed into a PCM. I have been under the impression that it'* better to run a PCM with correct fuel tables than an AFC. Actually, I think I got this idea from Bill . Any thoughts?
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Originally Posted by big_news_1
Yeah, that doesn't sound like a bad idea. Like the guys over at IACGP were saying, if I had an AFC I would be able to dial in the fuel trims, then take the numbers from the AFC and have them programmed into a PCM. I have been under the impression that it'* better to run a PCM with correct fuel tables than an AFC. Actually, I think I got this idea from Bill . Any thoughts?
Another reason is that the maf sensor is one of the variables used to calculate up and down shifts at partial throttle. Changinging the maf percentage drastically will change when your partial throttle shift points are a little. This isn't really a big deal though and your settings have to be over 10% off to really notice)
And for 4T65 OBD2 cars, since the line pressure is controlled electronically, the shift firmness will also change if the maf percentage is off by over 10% or so.
BUT the the mini-afc is a nice tool since you can tune your car whenever you want, you can use it as a reference to tell your programmer how to change your a/f, and when your programmer is finished you can re-sell the afc.
An important thing to remember is that your a/f is pretty off and a programmer will not be able to nail it on the first try.
If you get a mini afc, you can be running safer in a shorter amount of time too. Instead of running on a dyno/or around in general with KR and then getting your pcm reprogrammed, and reprogrammed agian.