Rough running Viper, need ideas...

[kwkshift]

I just installed a 510 stroker motor in my '97 with a Vec2 to help tune everything. I have a couple of odd problems, though.

1) At part throttle driving, either while cruising or just pulling away from a stoplight, the car will buck and lurch.

2) If I do a full-throttle blast someitmes the car seems like it goes into a "limp-mode" or something. It has no power, idles like it's a stock car, etc. There is no check engine light or anything. Usually when this happens, I have to turn the car off and turn it back on to get it running right again.

The car has new Mopar plugs, fuel filter and Mopar oxygen sensors. I thought it may have been a TPS problem, but I put on a new one today to test out and the problem is still there.

I can provide detailed info. about the engine combination if needed.

Thanks!!

 

[kwkshift]

Anybody?

 

[Buckeye Viper]

Reflash PCM?

 

[KepRght]

sounds like its all computer tripping out. maybe bad O2;s telling the pcm info that isnt real causing a messed up tune. sounds 100% computer related to me. get a freshly flashed PCM from someone like west coast who can flash the stock PCM, call them tell them your setup & they will ship it out. post on here if that resolves the issue. good luck!

 

[KepRght]

if the fresh pcm doent fix the issue, im thinking it could be a bad ground causing the pcm & other systems not to get juice randomly

 

[Randy]

1) At part throttle driving, either while cruising or just pulling away from a stoplight, the car will buck and lurch.

Sounds like the normal throttle sensor coordination problem common with Gen I cars and still happens to some extent on the Gen II's despite the single throttle cable. You have to verify the throttle on the side of the intake with the TPS sensor (left side?) opens ever-so-slightly before the other side. Otherwise, the TPS sensor is telling the computer that you are still not giving it any gas, when in fact you are moving at very low throttle opening. There is a screw adjustment on the linkage between the two throttle bodies so you can set this.

 

[kwkshift]

I'm on the right track with the bucking issue. I had to mess around with the throttle body linkage and set screw. I't not perfected, but it's better.

The biggest problem right now is how the car loses all power and drives like a Camry or something.

I could add a big ground from the chassis to the engine easilly if someone thinks that may be the problem.