Rev Limiter Problem

[Brenton928S]

Hi all, I have a slight problem with the rev limiter on my '82 928S. The problem is intermittent and i have no idea what is causing it. When driving the vehicle the limiter will sometimes cut in at 4000rpm and on one occasion i had the engine completely shut down at around 6500rpm. If i drive the vehicle on the highway for a period and get it really warm, the problem seems to go away. This is irrespective of the ambient temperature outside. This is getting quite annoying to say the least. Any Ideas?

[DPW928]

IIRC your rev limiter is part of the rotor in the distributor. Have you tried replacing it?

[JhwShark]

You have a rev limiter Rotor? If so, it should cut out at a specific rpm and not at variable rev's.

You may have a degrading Ballast resistor, they behave in the manner you indicate when they are ending their useful life; Temperature sensitive due to expanding and contracting wire creating an Open in the circuit.

Get rid of the Rotor if its a rev limiter one anyway...
Jon

[Brenton928S]

Thanks for the info guys. Iwill give it a go and see what happens.

[Brenton928S]

Where would i find the ballast resistor?

[DPW928]

Originally Posted by Brenton928S

Where would i find the ballast resistor?

On US cars the rev limiter is build into the ignition module. On early ROW 928's it is built into the distributor rotor. Not sure about the later ROW's.

[Opelotus]

What year US cars have rev limiters? I have US '84 and it doesn't have a rev limiter (unless it's broken), when my clutch went bad and I missed a shift it went up to 7500 RPM no problem

[DPW928]

Originally Posted by Opelotus

What year US cars have rev limiters? I have US '84 and it doesn't have a rev limiter (unless it's broken), when my clutch went bad and I missed a shift it went up to 7500 RPM no problem

Could someone have put a chip in it that raised the rev limit? IIRC the limiter should kick in around 6300 rpm.

[JhwShark]

Ballast resistors are on the fender wall near the distributor in front of the coil...size=a roll of pennies. Two of them one for the start circuit and the other for run. they each have unique stated ohm value that I have not stored in my RAM...

You have an '82s and no rev limiter is the distributor rotor, correct? I no nothing about rev-limiter in the transistor circuit and/or which MY is applicable to it. My '79 has a standard rotor and I have not experienced any rev cut out at any rpm's...

[Opelotus]

Not sure if it is possible to chip it in any way, but if it is, I would definitely reset it to stock. Don't like the idea of over-revving again, even if the engine can handle it...

[stepson]

I honest to goodness thought this thread was going to be about his wife sitting in the passenger seat complaining about the speed at which he was driving.