HELP, HELP please..major tuning issue
05-01-2005, 06:12 PM
#1
HELP, HELP please..major tuning issue Darton block
C5 corvette ELECTRONIC THROTTLE CONTROL 1998
11.2:1 CR
FMS 250/256 113 hydraulic cam .666/.680 lift Jesel Adjustadle rockers
48lb injectors
FAST 90mm intake/90mm LS2 throttle body.
Auto
headers/ Haltech intake
My car is having severe surging, hard start, erratic idle. Mail order tune was from Vette Doctors, An attempt was made by Mike Norris. Then a mail order tune by Futral. I was told there were mechanical issues because my manifold pressure was 8/hg.
What has been done
1. LS6 manifold TB swap (better but not gone)
2. LS2 Throttle body (better but unstable idle especially when cooling fans turn on off????????)
3. Took intake and valve covers off all valve/springs etc in good order ...replaced all gaskets, even rope seal between FAST intake. Replaced MAP,
4. Compression test 185-200 (two cranks)
5. 3-4% leak down
6. AFR with wide band (apprx 14.0)
7. Timing at 22 degrees (have tried all different timing settings)
8. 3/16" hole in Throttle blade (even without hole no difference...not much change with hole)
9. Hours of searching on-line (many many instructions used to tune)....no significant changes.
10. Smoke test for vacuum leaks...none
11. Cam was degreed when put in (all OK)
At this point I dont know what to do. I am not going to ship the car anywhere.........it was very expensive and came back the same way.
I am not sure what anybody here can do??????
I am ready to pull the motor.....sell car....etc
Tom Ulrich
I have thought off everything ......please help
C5 corvette ELECTRONIC THROTTLE CONTROL 1998
11.2:1 CR
FMS 250/256 113 hydraulic cam .666/.680 lift Jesel Adjustadle rockers
48lb injectors
FAST 90mm intake/90mm LS2 throttle body.
Auto
headers/ Haltech intake
My car is having severe surging, hard start, erratic idle. Mail order tune was from Vette Doctors, An attempt was made by Mike Norris. Then a mail order tune by Futral. I was told there were mechanical issues because my manifold pressure was 8/hg.
What has been done
1. LS6 manifold TB swap (better but not gone)
2. LS2 Throttle body (better but unstable idle especially when cooling fans turn on off????????)
3. Took intake and valve covers off all valve/springs etc in good order ...replaced all gaskets, even rope seal between FAST intake. Replaced MAP,
4. Compression test 185-200 (two cranks)
5. 3-4% leak down
6. AFR with wide band (apprx 14.0)
7. Timing at 22 degrees (have tried all different timing settings)
8. 3/16" hole in Throttle blade (even without hole no difference...not much change with hole)
9. Hours of searching on-line (many many instructions used to tune)....no significant changes.
10. Smoke test for vacuum leaks...none
11. Cam was degreed when put in (all OK)
At this point I dont know what to do. I am not going to ship the car anywhere.........it was very expensive and came back the same way.
I am not sure what anybody here can do??????
I am ready to pull the motor.....sell car....etc
Tom Ulrich
I have thought off everything ......please help
