7060 $85 454 intermittant hesitation with log. Please take a look.

So I've been driving my truck for a couple months now that it's tuned by myself. It runs dang good with the exception of an intermittent hesitation from a dead stop. This only happens every once in awhile but it's getting worse. It only does it when the engine is HOT. I've tried adjusting AE but that doesn't seem to be an issue and it doesn't seem to help.

Attached is a log. There's actually a couple hesitations in this log. But, If you look at "Engine Runtime" between 1836-1838 seconds frame by frame, you can see the rpm's drop out. Rpm's go from 1175 to 525 pretty fast. I can't find a reason WHY the truck acts like someone turned the key off then right back on?

Again, intermittent problem, truck is stock minus a 3" exhaust and a fuel pressure increase.

Im thinking of putting the stock tune back on it to see if it's my tune, or I have something failing electronically.

Please take a look at the attached log and see if you find something I can't.

Thanks for your help,
Ryan :)

It's AE related.

I'm tuning a friend's '71 Cutlass, that uses a '7060, $85, 4L80E, with the same issue. I couldn't get rid of it, tuning the highest point of the AE MAP table, then it dawned on me, that it's a delta table (total change, not absolute value), and adjusting the values that would actually be seen made a HUGE difference, still there a bit, but once I realized this, the tuning session was pretty much done, and thought we would have gotten back to it by now.

If you have a WBO2 to watch, this becomes more apparent, the NBO2 is just too slow, through the ALDL to see the lean spike in AFR, when it happens.

Thanks for the help!

Can you take a look at these values and see what you think? Below are screen shots of my "adjusted AE" that I've added because that's what I thought my problems was. Also shown are the stock AE tables.

I have 8-10* more timing in the 1200rpm/50-55kpa spark areas and this seems to be the problem area where it starts. Maybe I'm significantly PAST MBT? I don't have any knock?
I have also adjusted the "coarse" AE adjustment in the coolant table at the 80, 92, and 104*C areas.

Take a look.....

stock AE

http://i23.photobucket.com/albums/b3...ct/StockAE.jpg





Modified AE

http://i23.photobucket.com/albums/b3...adjustedAE.jpg

I think you got the best help from Six Shooter here so I'm just going to lurk and learn the PCM that gives me hell every time I touch one... (me, my luck, the vehicles, PCM is good)

Quote:

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I have 8-10* more timing in the 1200rpm/50-55kpa spark areas and this seems to be the problem area where it starts. Maybe I'm significantly PAST MBT? I don't have any knock?

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But you need to rule this out. Can have detonation and not hear or see it... Looked at one I did tune and was about 6 past stock here too!