Hey guys I’m kind of new here but I have been having some problems with the way that my car is running. I have a 1987 grand national that I recently rebuilt the motor. During the process I just replaced all bearings and seals, installed ARP main cap studs the new rings the block was boiled and honed. The heads had a valve job done and I used new ARP head bolts for the assembly. All the work was done by Ace crankshaft here on Long Island. The performance parts I added was a set of tubular headers, t04e turbo with a 50 trim wheel, external tial wastegate, custom 3.5"-3" downpipe, front mount intercooler, and a adjustable fuel pressure regulator along with a 255 lph fuel pump. The next thing that I’m getting is a chip/60# injector combo from turbo tweak. I also replaced my maf with an actual ac Delco product.
The problem: when in park and the car is idling, if I tap the gas it’s very hesitant to rev up and once it finally revs up, it comes back down to idle and wants to stall. The other problem I’m having happens when I’m driving. When I go to take off from a stop, the car shakes and shutters a little bit.
Some results I obtained from my friends Mac tools scanner (all are in idle):
O2 voltage: .44v-.71v<very erratic
O2 cross counts: 0 but a number would flash for a quick second such as 10, 17, and 23
Tps: .43v(steadily increases as the pedal is pressed and wot is 4.57v)
Maf: ~7-8 g/s(steadily increases with rpm)
Int: 128
Blm: 110
lv8: 41
Iac: 46
I checked the resistance across the coil towers
I got 13.58, 13.12, and 13.03
The only thing I can think is wrong is the chip needs to be replaced. Or the other thing I was thinking was that the gas was bad. When I replaced the fuel pump, the tank smelt funny. There was only a little bit of fuel in there so I just filled the tank up completely with 93 octane. But I have since then ran all of the gas threw it and there is no change.
Any input would be appreciated. I have been emailing back and forth with some people but haven’t got any answers yet. I will be posting on some other forums as well.
Thanks a lot,
Matt.
The problem: when in park and the car is idling, if I tap the gas it’s very hesitant to rev up and once it finally revs up, it comes back down to idle and wants to stall. The other problem I’m having happens when I’m driving. When I go to take off from a stop, the car shakes and shutters a little bit.
Some results I obtained from my friends Mac tools scanner (all are in idle):
O2 voltage: .44v-.71v<very erratic
O2 cross counts: 0 but a number would flash for a quick second such as 10, 17, and 23
Tps: .43v(steadily increases as the pedal is pressed and wot is 4.57v)
Maf: ~7-8 g/s(steadily increases with rpm)
Int: 128
Blm: 110
lv8: 41
Iac: 46
I checked the resistance across the coil towers
I got 13.58, 13.12, and 13.03
The only thing I can think is wrong is the chip needs to be replaced. Or the other thing I was thinking was that the gas was bad. When I replaced the fuel pump, the tank smelt funny. There was only a little bit of fuel in there so I just filled the tank up completely with 93 octane. But I have since then ran all of the gas threw it and there is no change.
Any input would be appreciated. I have been emailing back and forth with some people but haven’t got any answers yet. I will be posting on some other forums as well.
Thanks a lot,
Matt.
