Engine cuts off @3000 RPM
 

Hello everyone. This is my first post. Hopfully you may be able to help me! Two weeks ago, my engine started to cut off @3000 RPM. The transmission shifts normal between 2000-2700 RPM. However, if I press on the gas, it cuts off @3000 RPM regardless of the grea that I am in! When I'm crussing on the highway, it still does not let me go pass 3000 RPM making my top speed 72 MPH. I you guys can give me any inputs I will realy apreciate it. Thanks in advance.
PS. I will be reading the other threads to see if I can put in some of my input!:)

I forgot:
It is a 1995 C280.

3000 rpms
 

Inky -

I had the same problem. You need to have the Fuel Pump relay checked. This relay switch may have a governor that restricts rpms to 6,000. If so, it has gone bad - I am 99.9% sure this is your problem.:)

Thanks for the quick response. Where is the fuel pump relay located?

The fuel pump relay on a C280 does not have any decision making capabilities. It is a dumb relay that has its decisions made by the HFM controller.

You should check for fault codes in the HFM and EA/CC/ISC modules.

OOPS
 

Thanks Steve - I just saw the first post and didn't realize it was a C280.:(

Steve: Thanks for the clearing up! Where is the HFM controller located?

Someone told me it might be the OVP. Is that true?

I doubt it. The OVP causes much different problems with the HFM systems. It could cause the car to stop running, but I can't think of any reason why it would do it repeatedly under rpm conditions.

You need to know what is ceasing when the car cuts out. The simlest start is to read the fault codess. It may lead nowhere. There are many things that self-diagnostics won't cover but real testing is complicated.

InkyWinky,

Your car seems to be acting as though the rev limiter is at 3,000 RPMs, instead of the regular 6400 (or close to) RPMS, correct?

SteveBFL, what controls the rev's? In other words, what 'chip' or relay controls the rev limiter? I have heard once before that the contacts in there got dirty and it was causing rev limiting at the wrong time.

There are many "limp home" substitute values that modern controllers institute to protect them selves. I know of one at 4000rpm and one I think around 1800 rpms. I know of nothing at 3000 rpms.

Most of these strategies are involved with throttle control. The system most responsible is EA/CC/ISC or CC/ISC (electronic accelerator/cruise control/idle speed control).

Ohhhh, ok, I see now.
That makes perfect sense. Inky, you must take it in to have all of the codes read!!! Good luck and let us know what it was!