The other day I finally took the car out for a spin around the neighborhood after a 2 month hiatus. In those 2 months I did a semi wire tuck on the drivers side, relocated the battery to the trunk, ran all new 1ga cable, added 1ga grounds, with extra grounds all over. All wire terminals are brass with heat shrink tubing. I wired in a MSD 2-Step module to the existing 6AL ignition, added a fuel pressure gauge on the cowl, and new aftermarket gauges under the radio. Other than that, nothing else was touched or has been altered.
The car starts right up, idles fine, everything is working and I have good voltage everywhere. I take it out for a spin after it's warmed up, and it does fine under normal driving. If you were just driving it to work in the morning you wouldn't know there was any issue. But when I stab the throttle, it starts breaking up at around 4k rpm. It's a sudden power loss, spitting and popping. The fuel pressure gauge doesn't spike or drop more than it should. It's almost like it's hitting a rev limiter, but it still pulls through it. This happens when I'm just sitting in the driveway too, not only under a load. Cold or warm, it doesn't matter.
At first I thought it was something to do with the MSD stuff, so I swapped pills in the two step and it's definitely working fine. I then bypassed the 6AL box altogether and the hesitation is still there. I swapped the MSD ignition coil since I have a new one, and no change. Vacuum is good, no leaks.
So today I swapped in new spark plugs, checked TPS, readjusted the timing, swapped MAF for a spare I have... No changes. I played with the FPR with no change. All the old plugs looked normal, and I pulled the new ones after half an hour of driving and they looked fine.
The gas is 93 octane from 2 months ago, brand new fuel filter, 255 fuel pump. Car is NA 5.0 with H/C/I, long tubes and 3" exhaust, 65mm TB, stock injectors and stock A9L with a 5-spd. Car ran great before I did the wiring cleanup and battery relocation. I'm confident in my work and don't believe any of those things I did are the culprit. This seems like fuel or spark. I know the injectors are maxed out and it needs a tune, but it's about to get boosted with standalone, so I didn't bother. The car ran perfect and clicked off low 12's on drag radials 2 months ago.
Any ideas? Thanks
The car starts right up, idles fine, everything is working and I have good voltage everywhere. I take it out for a spin after it's warmed up, and it does fine under normal driving. If you were just driving it to work in the morning you wouldn't know there was any issue. But when I stab the throttle, it starts breaking up at around 4k rpm. It's a sudden power loss, spitting and popping. The fuel pressure gauge doesn't spike or drop more than it should. It's almost like it's hitting a rev limiter, but it still pulls through it. This happens when I'm just sitting in the driveway too, not only under a load. Cold or warm, it doesn't matter.
At first I thought it was something to do with the MSD stuff, so I swapped pills in the two step and it's definitely working fine. I then bypassed the 6AL box altogether and the hesitation is still there. I swapped the MSD ignition coil since I have a new one, and no change. Vacuum is good, no leaks.
So today I swapped in new spark plugs, checked TPS, readjusted the timing, swapped MAF for a spare I have... No changes. I played with the FPR with no change. All the old plugs looked normal, and I pulled the new ones after half an hour of driving and they looked fine.
The gas is 93 octane from 2 months ago, brand new fuel filter, 255 fuel pump. Car is NA 5.0 with H/C/I, long tubes and 3" exhaust, 65mm TB, stock injectors and stock A9L with a 5-spd. Car ran great before I did the wiring cleanup and battery relocation. I'm confident in my work and don't believe any of those things I did are the culprit. This seems like fuel or spark. I know the injectors are maxed out and it needs a tune, but it's about to get boosted with standalone, so I didn't bother. The car ran perfect and clicked off low 12's on drag radials 2 months ago.
Any ideas? Thanks
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