*** do I have to buy now

[mrviper99]

Have been losing my mind and wallet at the same time. 96 GTS rebuilt engine put in first of year, ever since then I've been running poorly not any fault of the engine hard parts though. I think its all in the soft parts or electrical. At first engine seems to bogg down going to WOT around 3200 on the VEC 1 it shows going lean. Have read all the post and checked wires resistance, checked and changed plugs, and back again. Changed fuel filter, checked fuel pressure, changed battery. Next changed PCM. Through all of this no change, except idles better now when stopped. Have found I have a non consistant spark on the 6 cylinder, and a brief blip on other so weve ordered a set of coil packs. I say we because the Viper tech at the dealer is working on this with me. Now take I take the car out today and the thing wants to blow up, drive down the freeway reach 70 mph put the car in neutral and the engine wants to stay at 2500 rpms then it drops to 2000 rpm then right back again. When it does that its right away like something electrical or a sensor is making it drop then it jumps right back up. I can be stopped or going 70 it will do the same thing. Sometimes it jumps up to 4000. Little crazy sitting at a light and the engine wants to scream. Have plans to have the coil packs installed on Monday, if someone has any ideas please chime in. Summer half over and no good times with the car, just a lot of money going by by. Thanks

 

[Bad_Byte]

Vaccum leak maybe?

 

[99 R/T 10]

Vaccum leak maybe?

I'm with Bad Bite, vaccume leak. Check the intake manifold with Carb caleaner ans see if there is a change in engine noise or speed. Good luck.

 

[Jeff Torrey]

RPM's change as described when the fan kicks on and off on my car.

 

[FE 065]

I don't think the car would rev high if it was a vacuum leak, I think the computer would add alot of gas to compensate, rather than just a high idle like a normal car. -And it would run like sh*t.

 

[kowalski vanishing point]

'97's had problems with intake manifold gasket leaks
I'm not sure about 96's.

When mine was bad it would idle at 3000 rpm.
Not a hard job to replace both sides.

 

[Bonkers]

I don't think the car would rev high if it was a vacuum leak,

I'm told on Fuel Injected cars that high rev is a symptom of Vac Leak. Mine is doing the exact same thing but I cannot find where the leak is yet.

 

[Ulysses]

High revs are symptoms of vacuum leaks or it could be that the IAC needs to be cleaned or changed out or the ICM is going bad.