Don't know what to do, not driveable
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Car: 1989 Pontiac Trans Am GTA
Engine: 357 Tuned Port Injection
Transmission: Borg Warner T-5
Axle/Gears: BW 3.45 9-Bolt
Don't know what to do, not driveable
So I've been working on my project TA for about 2 years now. Man time flies. It now has a .040 350 in it, .250 domed pistons, holley aluminum heads (68cc), converted lt1 intake, comp cams 230/236 @ .50 280/286 seat 114sep .590/.590 lift, hedman shorty headers, full dual exhaust, converted to speed density 727 underhood ecm running 8d.
I finally got this thing running this last weekend. Hooked up ye old laptop and ran datamaster for a quick run around the block. Took the datalog and sent it through vemaster with my bin. It seems to be helping, but there a huge obstacle that I can't overcome, and I can't figure out what it is. I can't get the car to accelerate worth crap. I have to jab the throttle and let off to get the car to buck forward. Doing this continually will eventually get me up to some speed. If I give it any sort of throttle, it just dies and coasts until I take my foot out of it, then it'll surge and come back down again. I can maintain a constant speed if I just barely hold the throttle. But I can't get the car to accelerate smoothly, just kind of rock it violently up to speed.
I've checked:
-Distributor timing (8*)
-Re-adjusted rocker arms
-Compression
-TPS (functioning fine)
All of my settings in the bin are correct for the car (i.e. inj constant, cyl volume, base timing, etc.) For the time being, the engine is breathing through the stock air filter and intake hoses from an 89 maf firebird. I didn't think that would cause a problem, but never thought to take it off and check (don't want to run without an air filter). I'm using the stock timing tables from a 91 305 m/t bin. I didn't want to play with spark tables until ve was somewhat close. I did have an issue with the ecm not reading vehicle speed, but I've solved that problem and the issue is still there. I don't know what else to do. Any help is appreciated as always. If you have any more questions, please ask, as I will be checking this often. I want to get my TA back on the road
Edit: Forgot to mention, my map reading is ~65kPa at idle.
I finally got this thing running this last weekend. Hooked up ye old laptop and ran datamaster for a quick run around the block. Took the datalog and sent it through vemaster with my bin. It seems to be helping, but there a huge obstacle that I can't overcome, and I can't figure out what it is. I can't get the car to accelerate worth crap. I have to jab the throttle and let off to get the car to buck forward. Doing this continually will eventually get me up to some speed. If I give it any sort of throttle, it just dies and coasts until I take my foot out of it, then it'll surge and come back down again. I can maintain a constant speed if I just barely hold the throttle. But I can't get the car to accelerate smoothly, just kind of rock it violently up to speed.
I've checked:
-Distributor timing (8*)
-Re-adjusted rocker arms
-Compression
-TPS (functioning fine)
All of my settings in the bin are correct for the car (i.e. inj constant, cyl volume, base timing, etc.) For the time being, the engine is breathing through the stock air filter and intake hoses from an 89 maf firebird. I didn't think that would cause a problem, but never thought to take it off and check (don't want to run without an air filter). I'm using the stock timing tables from a 91 305 m/t bin. I didn't want to play with spark tables until ve was somewhat close. I did have an issue with the ecm not reading vehicle speed, but I've solved that problem and the issue is still there. I don't know what else to do. Any help is appreciated as always. If you have any more questions, please ask, as I will be checking this often. I want to get my TA back on the road
Edit: Forgot to mention, my map reading is ~65kPa at idle.
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Car: 92 Form, 91 Z28, 89 GTA, 86 Z28
Engine: 5.7 TPI, LG4
Transmission: 700R4, 700R4
Axle/Gears: 3.27, 2.73
Re: Don't know what to do, not driveable
Sounds lean to me. What injectors are you using? Do you have a fuel pressure gauge? It doesn't blow black smoke when doing this, right?
It's likely because you're trying to run closed loop, and at low RPM, the INT will drop to the lower limit, but, at open throttle it needs to be much much more... That surely won't have fun in closed loop at idle.
Do you have a wideband??? Save yourself and your engine, and get one.
It's likely because you're trying to run closed loop, and at low RPM, the INT will drop to the lower limit, but, at open throttle it needs to be much much more... That surely won't have fun in closed loop at idle.
Do you have a wideband??? Save yourself and your engine, and get one.
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Car: 1989 Pontiac Trans Am GTA
Engine: 357 Tuned Port Injection
Transmission: Borg Warner T-5
Axle/Gears: BW 3.45 9-Bolt
Re: Don't know what to do, not driveable
The injectors are FMS 36# brown top injectors. I haven't put a fuel pressure gauge on it yet. I will have to do that and see what is going on. Thanks for your help. I will get a wideband for it soon, but funds just don't permit one as of yet.
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Car: '87 Formula
Engine: Ramjet 350
Transmission: T56
Axle/Gears: 3.23
Re: Don't know what to do, not driveable
Did you check for codes. Are you SURE that you are getting spark timing correctly? You can look at a log and see spark timing retard to find this out.
I had a problem earlier this spring where the car woudln't accelerate hardly at all, and come to find out I had the wrong knock sensor in it which was causing the computer to pull rediculous amount of timing.
I had a problem earlier this spring where the car woudln't accelerate hardly at all, and come to find out I had the wrong knock sensor in it which was causing the computer to pull rediculous amount of timing.
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Car: 1989 Pontiac Trans Am GTA
Engine: 357 Tuned Port Injection
Transmission: Borg Warner T-5
Axle/Gears: BW 3.45 9-Bolt
Re: Don't know what to do, not driveable
Thanks for the replies. I won't be near the car again until this weekend, so I'll try that this weekend. Pretty sure it's not pulling timing, but I haven't checked that yet so... Keep your fingers crossed. I really want to get this figured out. Thanks for your help thus far.
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