View Full Version : Strange drivability issue

07-22-2007, 06:51 PM
My 89XR7 has been acting up lately. It totally bogs down at low rpms, and then when you get to about 3K, it all of a sudden comes alive. It makes boost just fine, even reading about 8psi when I have it floored at 2K rpms and it is barely accelerating. It feels like you were just cruising, then put the gas to the floor, but it happens with the pedal kept at the same spot. I already went over the entire engine bay with some carb cleaner and fixed every vacuum leak (there were 4 or them!), one of which was the blower bypass feed line had come off, and that made it better for a few days, and now it is right back to where it was before. I also swapped out the MAF for a known good one with no change. Anybody ever have a problem like this before, or any ideas what this might be?

Oh yeah, I also was trying to figure out what this was and found my balancer falling apart, so I fixed that, but it still has the same drivability problem.

07-24-2007, 12:47 AM
Does you upshift light come on while cranking, and does it stay on after the car is still running?? May have a bad Crankshaft sensor...

Check your grounds too... just to be safe.

07-24-2007, 12:03 PM
Nope, no upshift light.

07-27-2007, 02:29 AM
My old 89sc 5sp did that for 2 months. Seemed that pressure washing the engine bay seemed to make it dissapear for a few days. Later i discovered that I needed a TPS sensor and a new Distributer module. Never had that same problem, I twas a bit strange under 3K, like the car was on a bungie cord being stretched. Once ya hit that magic rpm bang the cord released with plenty of go