MissLindsey

I have a 1995 trans am that is supercharged. After I changed the transmission, the car seemed to have a miss, but it didnt happen all the time. Now the car has slowed down 7 tenths at the race track and misses all the time. It starts missing at higher RPM's, like around 4200 and misses all through its shift at 6200. Is this a distributor problem?? Ive changed the coil and fuel pump. Thanks for your help!!!

Lindsey

Schweet97Z

iTrader: (35)

3 key factors make a engine run. Air, Fuel, and Spark. Sounds like you narrowed a few things down. Id replace the opti. How many miles are on it.

MissLindsey

Yeah thats what i was thinking but its such a pain in the *** i just dont want to lol. Its got 54000 on it but its been raced.

Schweet97Z

iTrader: (35)

HAHA they are a pain in the ***, but sounds like a good place to start. Many different veriables can cause the opti to fail. Condensation, corrosion, etc... Also you say it started to happen after install of the new trans? Auto or manual? I personally dont know of anything that could cause the car to act like this transmission wise but maybe someone else might chime if they had a similar problem.

sweetbmxrider

iTrader: (13)

i'm guessing you have your car tuned already? its probably the opti then. the more you do it, the better you get at it!

MissLindsey

yeah its tuned fine im sure. lol id rather not practice things like that! I am going to try spark plug wires first and then im going to attempt to change the opti if that doesnt work. Its going to take forever and a half with that dang supercharger. And i have had the tranny checked over twice cause it started out just missing right before the shift. but now its gotten MUCH worse and as soon as you go full throttle it just misses uncontrolably. I slowed down almost a second at the race track lol

Schweet97Z

iTrader: (35)

does it happen between shifts? it wouldnt be a shift solenoid would it? is it the same transmission that came out of the car? who rebuilt it?

MissLindsey

It does it as soon as you go full throttle until you let off. It has the same 4L60E tranny in it but a higher stall converter. The computer has since been changed and the shift silenoid has already been replaced and changed nothing. A local guy did it for me. It wasnt cheap lol

razorguy

iTrader: (2)

Sounds like the opti. When they start going bad they don't work so well in high RPM's..

94CamaroZ28SS

did you check to make sure your wires arent arcing? what about your coil arcing? I have this same problem with 14K on my OPTI and i just found out that my coil is arcing not off the wire but off the coil its self. check this first you dont want to throw more money into something that isnt broken

RoAdRaGe912

I see you replaced your fuel pump. Have you checked your fuel pressure?

Schweet97Z

iTrader: (35)

What year is your car and how high of a stall speed do you have?

Schweet97Z

iTrader: (35)

The reason I ask is because I know on the OBDI PCM's with a higher stall in a car, you can run into "stall wall" is the ODB-I computer's inability to accuratly calculate the difference in road speed and engine RPM given its basic parameters and then throws the car into limp mode until you shut it down.... ive never experienced it due to the fact my last car was OBDII so im not sure of all the symtoms. Im also probably over analyzing.

MissLindsey

If its arcing, i would be able to see sparks in the dark right?? I checked that last night, and i didnt see anything. However, my question is if the car has to be missing for sparks to be noticeable? the car doesnt start missing until 4000RPM, and i cant necessarily get up that far sitting in my driveway.

And if this isnt what "arcing" is, my bad, im not exactly a pro when it comes to cars. I just race them.

MissLindsey

its a 1995, and its got a stall speed of 2500 RPM

Yeah the fuel pressure is great, I have a gauge inside the car.

lt170chevelle

iTrader: (2)

i nhave a very similar problem with mine but i am closing my plug gap to see if it helps...possible spark blowout on mine...i will find out the outcome today after it dries up outside...best of luck on yours ...i have a 3400 stall but i dont think its stall wall on mine...but please explain exactly what happens when stall wall happens...i really dont know lol

PNYKLR-TA

iTrader: (1)

Thats a small stall for a supercharged car that you race, does it get alot of daily driving as well? or some other reason for such a small stall?

MissLindsey

Okay my bad i meant 3000. I do drive it around town every now and then when its actually running. Also i had the computer changed after i switched to 4:11 gears so all the computer spedometers and such should be correct....

Schweet97Z

iTrader: (35)

You seriously might want to consider looking into the stall wall issue I stated before. Its just really weird that this "misfire" started to happen after the converter and trans install. And with the bigger stalled OBDI cars they will act funny. Keep us updated.

Schweet97Z

iTrader: (35)

Stall Wall is where the stock shifting parameters in the PCM cant calculate engine rpm vs road speed, and will make the transmission short shift, skip shifts, not go into certain gears. Like I stated I doubt its not the issue since there is a big difference between a miss fire and skip shifts, its just weird the car started to act funny after the new converter.....