More problems with FAST 90 TPIS 90-help!
Thread Starter
8 Second Club
iTrader: (18)
Joined: Oct 2002
Posts: 2,609
Likes: 0
From: Waterloo, Ontario
More problems with FAST 90 TPIS 90-help! Well the 408 start up fine-a little rough on cold starts but hot starts are no problem. The major problem I'm having is if your cruising for a bit and come to stop the rpm stays at like 2000rpm? The only way to get it to come down is to turn the car off and restart. Also sometimes it will start to surge-like day after a burnout or something. Any help will be greatly appreciated-thanks!
Sounds like the blade is hanging open just a bit. My TPIS 90 was doing that.... fiddled w/idle decay rates and it helped but didn't fix the problem. Tried an external throttle return spring and bingo.... no more high idle hanging. Need to take the TB back off and have a closer look.... may need a lil' minor surgery.
Sounds like the Base running airflow and IAC Effective Area tables may need tweaking. You can adjust it if you have EFI Live or HP Tuners. Basically, you want your desired idle air (g/sec) to match your calculated air (dynamic air) at idle with a/c off and a/c on over a broad range of temperatures.
__________________
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
2013 Corvette Grand Sport A6 LME forged 416, Greg Good ported TFS 255 LS3 heads, 222/242 .629"/.604" 121LSA Pat G blower cam, ARH 1 7/8" headers, ESC Novi 1500 Supercharger w/8 rib direct drive conversion, 747rwhp/709rwtq on 93 octane, 801rwhp/735rwtq on race fuel, 10.1 @ 147.25mph 1/4 mile, 174.7mph Half Mile.
2016 Corvette Z51 M7 Magnuson Heartbeat 2300 supercharger, TSP LT headers, Pat G tuned, 667rwhp, 662rwtq, 191mph TX Mile.
2009.5 Pontiac G8 GT 6.0L, A6, AFR 230v2 heads. 506rwhp/442rwtq. 11.413 @ 121.29mph 1/4 mile, 168.7mph TX Mile
2000 Pewter Ram Air Trans Am M6 heads/cam 508 rwhp/445 rwtq SAE, 183.092 TX Mile
2022 Cadillac Escalade 6.2L A10 S&B CAI, Corsa catback.
2023 Corvette 3LT Z51 soon to be modified.
Custom LSX tuning in person or via email press here.
