93 GT help me tune this thing please!!!!

jodybennettii

New Member
Jul 23, 2008
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Tennessee
Hey I have a 1993 GT It has mostly bolt on modifications such as K&N cold air, flowtech shorty's, all 2 1/4 h pipe no cats, and 2 chambers, it has adjustable fuel pressure regulator, msd ignition, mallory coil, hypertech chip, underdrive pulley's on crank and water pump, A/C delete, smog delete, 3:73's, a King Cobra clutch and under hood fuel pressure gauge. THERE IS NOT A CAM IN THIS CAR in fact I don't think it has any motor work but don't know for sure I bought it almost exactly like it is now. It runs 8.99 - 9.20's at like 78 mph or so in the 8th.

Now to my questions??? My car used to idle weird when you first started it, it would go up and down. Idling between 600- 1000 rpm almost dying when it went to 600 rpm. This just occured when it was cold when it warmed up a little it smoothed out a little at idle. Also after it warmed up for 1-2 minutes a check engine light would come on, and when you punched it would sound like the top of the motor was coming apart (I think this was spark knok as this motor is not damaged). And it would feel really rough when you got into it i.e. vibration in the shifter from the motor. At first I thought this was do to leaking headers (can't ever keep these bolts tight) and So I put new aluminum gaskets on. That didn't fix the problem. So I checked the fuel pressure it was like 45 psi with the vacuum connected so I adjusted it to right at 35 psi with the vacuum off with the vacuum line on it sits about 28 psi at idle going up at WOT (wide open throttle) to 30-33 psi. The wierd thing is I took it for a drive the check engine light turned off, no more spark knock at full throttle, and no more roughness in the shifter when it's to the floor. I did mess with the initial timing when it was still messed up to get more power off the line. Now that's fixed it doesn't feel as strong as it did. (When it was cold it was fast when it was messed up and you punched it). Now for my question does anyone know if i could make it faster by adding or subtracting psi to the fuel, or could I add initial timing and make it faster. and does anyone have a suggestion for psi, and timing setting. I don't have a timing light so I'd be doing it by ear any info would be nice and appreciated. Also this motor has hyperutectic pistons (1993) so I can't run a power adder, what should I do to make the most power for the less buck any suggestions would also be appreciated. I don't wanna spend more than 400.00 but wan't a significant difference is this even possible. This is my first post sorry for the book Thanks Jody
 
well one's things for sure, you need to time it with a light. I don't know how you're timing it by ear, but that's surely not accurate and a light is cheap at the auto parts store or you could easily borrow one.

35 sounds a little low without the vaccume, maybe bring that back up to 38 or so. I'm out of time, I'll post more later. good luck!
 
well one's things for sure, you need to time it with a light. I don't know how you're timing it by ear, but that's surely not accurate and a light is cheap at the auto parts store or you could easily borrow one.

35 sounds a little low without the vaccume, maybe bring that back up to 38 or so. I'm out of time, I'll post more later. good luck!

Yes. Use a timing light.
Also, I'm not certain but, I think that hypertech chip advances the timing anyways.
I would take the chip out and advance the timing to 14 advanced, run 93 octane, and i believe that you'll get the same results as with the chip.
Stock fuel pressure is between 38-40 with vacuum off.
The check engine light could be faulty O2 sensors. The best way to find out though is to get the codes with a scanner (cost $30.00)
You can run a power adder with the hyperutenetic pistons if you have everything set up properly.You need to have all the right componants that work with your set up. And have it dyno tuned with a custom burnt chip. Check out Kenne Bells site for superchargers. It won't be cheap, but it can be done.
I would get the car straightened out first the way it sits, before adding more go fast parts.
A head , cam and intake upgrade can give you some good naturally aspirated horse power. Do this first for an upgrade, then when you decide to go with a power adder the results will be much better.
Good Luck!!!


1993 GT Mustang / Ford Racing GT-40 Crate Motor B-303 Cam / 24 lb. Injectors / Stock Ignition / MSD EFI Blaster Coil / Edelbrock 5.0 Upper and Lower Intake with BBK Phelonic Spacer / Professional Products 70mm Throttle Body / C&L C.A.I. w/76mm MAF / Stock Air Box w/K&N Panel Filter / Holley Adjustable Fuel Pressure Regulator / Electric Fan / BBK Underdrive Pulley's / A.C. Removed / BBK Short Headers / Flowmaster Exhaust / Tremec T-5Z / B&M Short Throw Shifter / Alum. Driveshaft / 4.30 Gears / Eaton H.D. Posi / Moser 31 Spline Axles/ Subframe Connectors / Line Lock / Driveshaft Loop / BMR Upper and Lower Control Arms / Lakewood Adjustable Drag Shocks/ Holley 190 lph Fuel Pump /
 
still can't get the gt tuned right

well thanks to everyone that wrote back however the car never gets less than high test not even midgrade and it is now set at 14 degrees initial timing and I also installed new plug wires I reset battery and check engine light went off the car hasn't started the funny idle again but feels like the fuel is cutting out under WOT still no light to the guy that wrote about the hypertech chip I think you were on to something that's why I decided to reset brain see fuel pressure was off and the chip and brain compensate so I figured try that before replacing fuel pressure regulator (ohhh yeah by the way while tinkering under the hood today I noticed as the idle was going up and down so was the fuel pressure fluctuating 20-60 psi now since I have reset the idle is not doing the fluctuating but I also only took it around the block will post more tomarrow
 
as I posted on the one i posted it ended up being a spark plug that was way too long it hit the piston and the whole top was missing I was running on 7 cylinders here a shout out to hypertech that changed the timing and whatever else it adjusted to make it seem like the car was still on all 8 untill you put a load on the car then it missed thats a ggod ecu huh shout out to everyone that replied thanks