Car wont go over 3500 rpm !!

[glhcsx364]

I agree with Kevin

Just replace your TPS. It will not throw a code and even if you use a DRB it still will not throw a code. It will blink in "I's" and "O's"

They are pretty cheap and I have had the same problem on 2 cars.

[Cornflakes_GLHT]

I replaced the TPS and it does the same thing .... this is getting really funny !!

[Shelby VNT]

I once had a somewhat similar problem with my VNT Daytona. It turned out to be a cracked vacuum hose, but the trouble was the car would idle at 3,000 rpm, no less, and the engine would never run any faster then 3,000 rpm. Giving it more throttle resulted in a terrible stumble, with missing and jerking while driving down the road. I could not open the throttle even a little or the car would stumble.

It doesn't sound like you are having troubles getting the car to idle, but since so many other good ideas have been posted, I thought I'd just suggest you double check the vacuum hoses and their routing. The VNT cars are pretty sensitive to the vacuum leaks and routing.

[B.A.P.]

One of the local guy's CSX-VNT had the same "won't rev over 3500 rpm" problem.

MoparBoyy diagnosed it as a bad distributor. I don't remember if it was a loose shutter plate or what, but a fresher used distributor fixed the problem. I think he had put a different pick-up-plate on it as well for good measure.

[VntEs]

JT..........thought it was the distributer gear was so worn that it had a ton of slop causing the timing to go nuts at higher rpm's.

[B.A.P.]

Quote:

Originally Posted by VntEs JT..........thought it was the distributer gear was so worn that it had a ton of slop causing the timing to go nuts at higher rpm's.

Hey, maybe that was it, that sounds familiar too... worn intermediate shaft gears... All i really rememeber is that it involved the distributor...

Heck, mine actually skipped a tooth between the I-shaft and oil pump once, lined up all the timing marks and the distributor rotor wasn't pointing at the #1 wire! Keith had it happen to his SC too, and had tipped me off on it when i was trouble shooting.

[Cornflakes_GLHT]

thanks guys ...

i did remove the distributor and checked it out ... gears are good... the engine has 85 000 km... i know it doesnt really matter, but everything checks out fine. there is only one more test to do and ill try to replace the computer next week, ill try to find one...

thanks again

[ThreeTurbos]

isnt his base fuel pressure at the rail a little low?

when the car starts to skip does it lean out on the a/f??

[nemiro]

I agree with other assessments on the VNT actuator. I've had leaks in vacuum lines that would not even allow a VNT to start and run. I had heard of this, but did not believe it until I had a car do it. Take a vacuum line straight from the intake manifold to the 'B' port (should be the bottom port, the larger one) of the VNT actuator. Disconnect the top line ('A' port, WG port, errr, the small one). Start the car, if your vacuum is good, that arm should move more than 1/2". once it does, try revving the car. If it now revs where it should (will make little to no boost), then your problem is vacuum line related. Yes, a pinhole leak on the B side will cause your problems. The B side is notoriously hard to diagnose, and is plumbed in the most awful way. If that does not fix the problem, try actually swapping MAP sensors. I had one fail one of my 91 R/T's that showed no codes, read good on the OTC, and would shut the engine down at random. Took a long time to figure that one out.

[nemiro]

Also, on that VNT acuator rod, make sure the end of the rod is hooked up to the vane pivot, ie, make sure the rod is actually hooked up to something.

[Cornflakes_GLHT]

i will try the vaccum test tomorrow

i did the actuator test but starting the car and checking if it moved. it does, i make boost fine and there is no problem with that ... (that i can see).

and i allready tried to swap my MAP. didnt do anything.

Pascal