I'm about to pull my hair out here, 7060 idled fine, no hunting for an idle, same RPMs and nothing mechanically changed. Swapped to the 7427 and I can't get it to stop oscillating. I have made a few changes and its better, but still not gone in park/neutral. Is there a way to slow the IAC?
I've attached my tune...
94 Blazer, Turbo'd 350 TBI - DD
1991 2500 Suburban Adventure truck - 4wd conversion, 4-link F/R, 582ci CNP Big Block with Terminator X EFI backed by a 6L90 and twin stick'd NP205 t-case
2012 Porsche Panamera Turbo - Date night car :)
1979 16' Action Marine/"Johnny Cash" Merc Bridgeport Champ Motor - Metalflake Maniac
Maybe you can post a data log? Maybe the idle is going into Async?
Please include the .adx file used with the .xdl file.
dave w
Let me know when you fix yours. Haven't figured out how to calm mine down yet either.Originally Posted by 1BadAction
89 K1500 Scottsdale 5.7L 5spd 3:42 RamJet cam Dart iron TBI heads 427 PCM swap
95 C2500 Cheyenne 6.5L turbo diesel 4L80e 4:10 DB2-4911 Manual pump conversion 0411 PCM trans control 2Bar COS
05 Outback XT 2.5L turbo gas auto
Idle portion is at the end of the first log, and the second log is a little bit of me idling through a parking lot, foot off the gas... with a surge...
94 Blazer, Turbo'd 350 TBI - DD
1991 2500 Suburban Adventure truck - 4wd conversion, 4-link F/R, 582ci CNP Big Block with Terminator X EFI backed by a 6L90 and twin stick'd NP205 t-case
2012 Porsche Panamera Turbo - Date night car :)
1979 16' Action Marine/"Johnny Cash" Merc Bridgeport Champ Motor - Metalflake Maniac
I only had a few minutes during my lunch break to crunch / combine both data logs. I used an Excel spreadsheet to crunch the data logs. The attached screen shots are a summary view.
Two things:
I did not see Async active at idle.
I did not see AE active at idle.
I find it interesting there are knock counts in the idle RPM / Kpa.
dave w
Comp link bar roller lifters, they're noisy. From the logs I have done looking at knock counts to fine tune my spark, it doesn't seem to effect anything above idle very much.
I understand it is slightly lean in the other light load areas, that's why the first datalog was long, I'm going back to adjust the VE tables this evening.
When I first got it warmed up with all the IAC tables stock, it would oscillate bad enough to hit AE. I almost eliminated the spark compensation and it is much better. The second bin is better than the first one I posted, that bin is the one that both of those datalogs are from. I seem to be going in the right direction, just wish there was a way to slow down that IAC response time slightly.
94 Blazer, Turbo'd 350 TBI - DD
1991 2500 Suburban Adventure truck - 4wd conversion, 4-link F/R, 582ci CNP Big Block with Terminator X EFI backed by a 6L90 and twin stick'd NP205 t-case
2012 Porsche Panamera Turbo - Date night car :)
1979 16' Action Marine/"Johnny Cash" Merc Bridgeport Champ Motor - Metalflake Maniac
Have you changed any of the fuel trim parameters? The O2 switching points look lean and the fuel trim parameters look pretty aggressive for a non-stock engine IMO. These can contribute to surging at idle and low throttle settings.
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