So I am driving along and I see the tach jumping a little bit. I think "man, I just replaced the VP 15k ago!" It goes away.

A few weeks later I get a "check engine" light. 3 key cycles later it is gone. It did this again the next day. It goes away.

So the other day I am on the second leg of a 1 hour drive and the tach starts jumping wildly. The noise from the engine is not matching up to what the tach says. The only change in the engine is that a few times it dropped to 0 and I could hear the engine start to cut out.
It was like -2 outside so some say fuel could be the issue. I have a post filter gauge that is showing just under 10 psi and I had been driveing for over a 1/2 hour with 1/2 tank of fuel. I did not get a "water in fuel" light, so I did not suspect that.

I have noticed that it has been having a hard time getting into overdrive in the last week but I atributed that to the -10 weather and needing to get warm. Once it is up to temp this goes away. I must admit though that it has not done this before the last few weeks.
When I got off the highway and on secondary roads the problem seemed to go away. On my way to the repair shop this morning it ran fine.

Any thoughts?

 

ANYONE?? I am going nowhere fast...

 

I saw a post just yesterday about a similar situation. He cleaned his battery connections and his issues got better.

 

A cam or crank sensor affects the tach. sometimes. Get the codes read with a scanner.

 

possibly ctm

 

"key on key off" for codes???

 

This kind of happend to me It finally went away after I cleaned all the grounds I could find.

 

When they looked at it at the shop they said that the battery terminals were loose. I hope that fixes it. I will know after work today. Thanks.

 

Did they hook a scan tool up? It should have had a stored code in one of the controllers. Hope the batterys were all it was.....but I have my doubts.