Quote:
Originally Posted by Mr_M//
This exact thing happened to me 2 summers ago, my car was running perfect. until I replaced the Turbo to ps2 (without upgrading the HPFP) and I replaced the plugs to NGK gapped .020. running stage 2 E30. then back to stage 2 ( still didn’t fix it).
I searched to resolve it,but with no confirmed answer. Some say spark plugs and others say coils or HPFP.
What I did to temporary fix the issue and also to confirm it was fuel related or if the plugged too small/ bad plugs.
. I add VP octane booster to the tank so I get easier sparks and I thought with race gas the car can run little leaner, that totally worked  .
Luckily after I changed the HPFP to Dorch stage 2 problem was fixed. |
octane booster doesn't make an easier spark, but if it worked, then your issue was most likely pinging / pre-detonation which resulted in the car protecting itself with significant timing retardation and maybe throttle closures.
OR
maybe it was unrelated at all since your real solution was an upgraded HPFP, which means you were likely having misfires due to low fuel pressure.