Need troubleshooting help

KenH · August 5th, 2007, 10:01 PM

My Viper has developed an intermittent problem. Sometimes when giving it some throttle either from a stop or on the open road, it starts bucking like it is getting a complete power cut which is coming and going about once a second. Backing out of the throttle causes it to run OK.

It may be RPM dependent. Once when it was acting up, each time I slowly increased RPMs to a little over 3000RPM, it would start bucking. When it did. the WBO would read about 11:1 instead of the normal 14.7 A/F. It makes me think that I am getting an electrical cut of some kind. When I would let off the throttle, it would run OK. I have only noticed the problem at part throttle.

I checked the TPS and it seems to read smooth over its range. I'm thinking perhaps something like the crank position sensor or coil pack. I know if I just take it into the Tech, it will run fine.

HP · August 5th, 2007, 11:06 PM

Do a search - It seems like others have had some luck with running an extra ground to the TPS .
That or replacing the O2 sensors

Disturbed · August 6th, 2007, 06:36 AM

Sometimes dirty TB will do the same thing. How many miles are on the car. After about 12kmi I had to clean mine. I had that same bucking issue. Cleaned them out and it went away.

KenH · August 6th, 2007, 10:50 AM

The car has 33K miles on it. I'll check the throttle bodies.

I have the extra ground on the TPS.

The O2 sensors appeared to be operating correctly using EASE scanner at least at idle, though I might replace them just to be safe. I had them go out on me once before and it gave similar symptoms, but it was constantly bad and not intermittent. The fact that I have not noticed a problem at WOT might indicate it could be the O2 sensors.

JGK95 · August 6th, 2007, 10:10 PM

If you're on the East coast. One word... Chuck Tator.

TimLippard · August 6th, 2007, 11:08 PM

Quote:

Originally Posted by JGK95

If you're on the East coast. One word... Chuck Tator.

That's two words!

-FROG- · August 8th, 2007, 12:52 PM

Quick qeustion for "dirty TB's"..... How does a dirty TB cause this? I mean, there are no sensors dirty or anything like that, or is there? Are you guys are just talking about some sludge on the inside of the TB? Wouldn't that only restrict a nano-CFM of air? I'm just trying to see how this can be the root cause because it doesn't seem logical. Also, are you cleaning off the butterfly too? Maybe some dirt on there?

What are you doing to clean them? totally remove them and blast them with some brake/carb cleaner or Engine Degreaser? Are you cleaning off the TP Sensor too and other related sensors?