I am a bit stumped at this point. I've read and reread everything I could find on the topic.
The Car
1991 Toyota Supra 7mgte 5 speed
Mods
Garrett 60-1 To4e turbo
RC 550cc injectors(just flow checked)
Walboro pump
Aeromotive FPR set to 41 with line off
AEM with wideband sensor feedback
HKS DLI
new OEM coils
new NGK wires
New NGK plugs(had Champions in on the dyno swapped them out) gapped down to .022 in testing
The Symptoms
At 3000-4000rpm, and full throttle at 2psi or greater, the car develops a severe skip, but will power through. Air Fuel ratios stay correct.
Observations
If you are under 75% throttle, it appears to drive through this range at boost without skipping, free revs perfectly
Diagnostic Process/things done
I have replaced all grounds with 8gauge wire, including from the coils to the head.
Swapped ignitors
Closed gap of CPS to .006 or so to ensure clean signal (I no longer get any signal errors in the AEM)
Rewired DLI to make sure I wasnt causing power starvation to the coils/ignitor
Confirmed full power even during skip at the coils
Comfirmed CPS resitances
Confirmed base timing
Reset coil dwell from the base "19" to "20"
Results
Car is much crisper with throttle response with all these checks done, but the car still has this severe skip/breakup in the 3000+ range.
I have had a similar symptom from a MK IV and it ended up needing a harness, but we could shake the harness and get a reaction, I do not have any result from shaking or wiggling connectors.
I'm at a loss and normally am the goto guy for tough stuff, any suggestions? Anyone good with a AEM with a similar modded car mind sending me a map in confidence so I can test with it? I still think it could be in the tune, as I just can't see anything mechanically with it. The TPS also sweeps fine..
The Car
1991 Toyota Supra 7mgte 5 speed
Mods
Garrett 60-1 To4e turbo
RC 550cc injectors(just flow checked)
Walboro pump
Aeromotive FPR set to 41 with line off
AEM with wideband sensor feedback
HKS DLI
new OEM coils
new NGK wires
New NGK plugs(had Champions in on the dyno swapped them out) gapped down to .022 in testing
The Symptoms
At 3000-4000rpm, and full throttle at 2psi or greater, the car develops a severe skip, but will power through. Air Fuel ratios stay correct.
Observations
If you are under 75% throttle, it appears to drive through this range at boost without skipping, free revs perfectly
Diagnostic Process/things done
I have replaced all grounds with 8gauge wire, including from the coils to the head.
Swapped ignitors
Closed gap of CPS to .006 or so to ensure clean signal (I no longer get any signal errors in the AEM)
Rewired DLI to make sure I wasnt causing power starvation to the coils/ignitor
Confirmed full power even during skip at the coils
Comfirmed CPS resitances
Confirmed base timing
Reset coil dwell from the base "19" to "20"
Results
Car is much crisper with throttle response with all these checks done, but the car still has this severe skip/breakup in the 3000+ range.
I have had a similar symptom from a MK IV and it ended up needing a harness, but we could shake the harness and get a reaction, I do not have any result from shaking or wiggling connectors.
I'm at a loss and normally am the goto guy for tough stuff, any suggestions? Anyone good with a AEM with a similar modded car mind sending me a map in confidence so I can test with it? I still think it could be in the tune, as I just can't see anything mechanically with it. The TPS also sweeps fine..
