Been have problems with my car. At wot, the car will intermittenly shift from 1st straight into 4th. It doesn't happen all the time, maybe 40% of the time. What would cause that?

 

To me this doesn't make sense from the way the solenoids work inside the transmission. Are you getting any codes? A good idea would be to look at a scan tool and view what the computer is telling the trans to do. In first gear the a and b solenoids are on . In second gear the a solenoid shuts off. In 3rd gear the b solenoid shuts off. In 4th gear the a solenoid turns back on. What you need to do is see what is happening when your problem occurs. It might be a good idea to see what the tps and also what the vss is doing. The a and b solenoids are also referred to as the 1-2 solenoid and the 2-3 solenoid. Good luck. Vince

 

Sometimes, with enough wheelspin off a launch the car will upshift into 2nd and bog bigtime. That needs to be tuned out. 4th would be a serious bog...

What speed are you moving when this happens?

 

My buddies car did that, unless you manually shifted it. We rebuilt the trans and it still did it. Found out that his stall was messed up. He sent it off and had it fixed and restalled (I'm not sure to what RPM) and the car was back to normal. Didn't make sense to me but it works now.

 

No that dosent make sense either

 

We even swapped tranny's and it still did it, the only thing that was the same was the tune and the stall. Had the stall repaired and put it in and everything works great now. I dunno what the hell to think of that!?!?

 

Strange ? I dont either unless it was actually not shifting to 4th but rather shifting straight into lockup maybe

 

Well, there are no codes. The converter has been shipped out and rebuilt since this started. We have also swapped trannies, but it still does it. We are currently waiting on a new wiring harness. We're thinking that there is a bad ground or a short somewhere in the harness. Although when we stripped the original harness and ohm'd it out we couldn't find anything wrong.

From what I've been told, the car is going straight into 4th. I'm not sure if it is being commanded to go there or just is going there.

I'm wondering if the 98 pcm, just can't support the engine and power that it's making. To my knowledge, I'm the only one with a LS2 402 in a 98.

 

You need to hook it up to a scanner watch the data stream and see if its commanding those shifts