r90camarors

First-the specs from what I know: 383 1-pc 2 bolt 10.5:1, dart pro 1 aluminum heads, zz4 hot cam with 1.6 aluminum rollers, 5.7 eagle H-beam rods, eagle crank. TPIS Big mouth base and runners, extruned plenum, vafpr, 58 mm BBK TB, and I believe 26 pph injectors. 2,800 stall, moser 9" 3.73 posi. Chip done via Ed Wright. Crane ignition and high flow fuel pump. edelbrock headers, slp catback. '91 map setup

The engine likes to backfire at various throttle openings and rpms, and is currently only running a best of 13.5 at about 100mph.

I know the first thing to do is some custom chip tuning. I am thinking the prominator with r/t tuner cat. I am thinking the injectors are too small, but read various hp ratings on particular ratings. I am assuming the combo should be at the 400 hp range, so would 30pph injectors be a good size? Which brand to go with?

I have also looked into the intake choice, and I think the TPIS setup should be good considering the size of the cam, which I believe is something in the neighborhood of .510"/.525", not too sure on duration though. However, I am thinking the 58 mm tb may be a bit much for the cam, especially with the aftermarket runners. Would the 52mm be a better choice or even the stock tb?

I just bought the car from a friend, still have to make the 800 mile round trip to get the Z up here. I would like to drive it, but need it to be reliable first. Any thoughts/ suggestions welcome. Thank you

89gta383

iTrader: (5)

Check all the basics first, timing, iac and tps sensors, vacuum leaks, exhaust leaks, trouble codes, etc. It sounds like something mechanical, like the timing is too far advanced.

r90camarors

Yeah, I have to agree. We have played with the base timing, and it is obviously in the chip. We can get it to run smooth down low, but then it is horrible up high, and vice versa.
The other problem I have is that my winaldl cable doesn't want to work on the z-28 (it works fine on the 8746 tbi ecm), and I have yet to try the other cable setups, so unfortuantly I have no data. Shoot, I forgot what it was like-no data logging is almost like being blind.