Ok the car was running fine today and then the tack started to bounce from about 800-1000, and the car ran like ****. And then the car started to miss pretty bad. the car starts but does not idel right. Then if I drive it it will accelerate (but lacks some power) untill I reach a constant speed and then it brakes up pretty bad untill I get deeper into the gas, and then the same thing at a constant speed it brakes up agin.

I bypassed the electronic ignition box and ran off the oppti with the same result. When I first started it up it ran fine and when it went into closed loop it started missing.

Also I scanned the engin and tranny and found no codes?

Aweek or to ago I had a problem with the idel surging. I scanned it and found the tps code I cleared it and it ran fine till today? Could it be the tps, but I am getting no code or mill light.

Any hellp will be greatly appriciated!

 

Check all your plug wires. I had this happen when I first got my LT1 running. Number 6 had come loose and was preventing spark on that cylinder.

 

They are all tight!

 

If the tach is bouncing it is either an ignition problem or wiring. Make sure all ignition connectors are tight(opti, module and coil) and check your grounds. A bad TPS could cause a miss, but I don't think it would cause the tach bouncing.

 

If the throttle vpltage is spiking or at the wrong range it would tell the computer that it was throttling up or down, I think....

If I am running an electronic ignition and using the opti as a trigger could the opti still cause problems?

 

How could you run the ignition without the opti?

 

the opti is there just not used to control or deliver the spark, The aftermarket ignition box doest that and uses the opti as a trigger, like a crank sensor.

 

What type of ignition are you running? The only one I can think of is the LS1 coil conversion or the one that uses Olds Aurora coils.

 

No its just an aftermarket lt1 ignition made by crane.

 

Are you using datamaster to scan it? Just wondering.

 

Unless they have come out with a new one the crane still uses the opti. It is an ignition amplifier that only boosts spark. The computer still relies on the opti for a signal. A bad opti can cause those symptoms.

 

I am using a snap on scanner!

 

Check your timing with the scanner. It can help locate opti problems. If the RPMs on the scanner don't jump aroung, you could have a faulty tach or tach wiring.