Half-Breed

[Zachalanche]

Finally the car is registered and insured. I took it for its first legitimate drive on real roads about a week ago. I must say this thing disappoints.....well maybe a better way to put it is that I haven't worked everything out yet.

The car cuts out pretty hard under full throttle. at first I thought it was a fuel supply issue. there was no problems like this when the car was on the dyno a few years back, so I wondered if it was related to fuel starvation under hard acceleration. the fuel cell has an internal baffle with trap doors so I don't think its unavailability of fuel, but I was suspicious of a kinked hose inside the tank so I replaced it with corrugated plastic line. Additionally The fuel pump was very very loud and this has since been corrected with a new Fuel filter/regulator.



After all that fun work the problem seems to be even worse which has me wondering if it is fuel related or something else.

On top of that the low speed drivability isn't great. not terrible but a little annoying. the engine rpm hangs around 2000 rpm for a long time when coming to a stop. and the the car is either bucking when you try to hold steady, or dead pedal when you try to accelerate (not completely dead, but not very responsive).

I read some things on other forums that mention the T56 Magnum has a 12 tooth reluctor wheel which doesn't play nice with the GMPP ECM which expects 40 teeth, and this can cause low speed drivability issues

Anyone her familiar with tuning GMPP stuff? and if so what is your tuning software of choice? I'm wanting to make some adjustments to the vss signal since my T56 reluctor ring has much fewer teeth than the ECM expects. this issue also doesn't allow my speedometer to calibrate due to low pulses per mile. Also, I'd like to look at the ignition map and see what the timing is at lower loads and speeds, and on crank. The starter has a hard time cranking when hot which has me wondering if the timing is too advanced during crank.

Any advice is appreciated.