I cut the multiplier to .06 overspeed and .125 underspeed... which for the most part eliminated the spark compensation. That helped the surge quite a bit, but didn't eliminate it.Originally Posted by brian617
I cut the multiplier to .06 overspeed and .125 underspeed... which for the most part eliminated the spark compensation. That helped the surge quite a bit, but didn't eliminate it.
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 am on my phone so can't look at you bin, what is your base timing? Timing is used to control idle more than IAC. Timing reacts faster. I would look more into a timing issue. Raise the timing at idle till you get the lowest KPA value you can, then back it off about 4 degrees. That should be you idle timing.
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Did you ever figure this out? Just looked at your bin, and your timing tables are pretty crazy looking. Your open and close throttle tables should match, at least in the areas around idle. You had 3 degrees difference. That could cause the idle to start to swing.
Try this bin.
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Yes, it's fixed. I'll post up the changes when I get a chance on a PC. I'm on my phone in South Louisiana right now, and heading on to Florida in it tomorrow.
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
Nice, wish I was heading south myself.
-1999 Hugger Orange SS, LS2 402 T56, 9 inch Ford 3.90 gears, Tuned with HP Tuners
-2002 Cavalier, Tuned with HP Tuners
-1994 Full Size Blazer ,383 TBI 4L60E, 4.10's, Tuned with Tunerpro RT (Where it all began)
Kind of forgot about this thread, but it was brought up again... So, after a bit of looking through other bins IAC logic in both OEs and ODs, I opened up my BHDH ($0E) tune, and a rock stock BJYM ($0D) tune in a second instance of tunerpro (with the correct XDFs, of course), then copied the BJYM IAC tables over to my BHDH tune, one by one. The SBC IAC tables are much less aggressive than the BBC tables are. The only other change I made besides this was to further lower the IAC flow VS IAC steps table, so (for example) 10% flow would be 13 steps instead of 21. On first start once it was up to temperature, it was NOT hunting, but idling a hair low. After about 10 miles driving around town with a few starts and stops, the ECM learned where it needed to be and it has been rock solid from then on, roughly 3000 miles and a bunch of starts and stops, from 15 degrees to 80+ ambient temps. I am extremely pleased with it.
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 changed it the 9th but that was only to make a slight cold start and open loop fuel adjustment. The idle logic has been the same since I left Dallas on the 21st of December.
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 wonder if it was a result of the change between the early and late style IAC passages on the BBC TBIs? I'm guessing the IAC logic in the 7060 was a lot less complicated?
I did some crazy work to my idle spark table and it seemed to help in my situation. Really cleaned up my cold starts. I'll post my .BIN when I get to my TP PC.
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
Possible, and the 7060 was much less complicated. It also had bad windup on a free-rev, where the 7427 IAC controls it very tightly.
Didn't need to do much of anything wild, just bumped the choke a hair richer. Now that I have the idle and VE nailed, it had a little bit of a cold start lean "dip" in the teens and 20s.
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
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