986 Forum - The Community for Porsche Boxster & Cayman Owners - View Single Post

Smallblock454 · 03-17-2015, 10:05 AM

Man, wrote a long text, got logged out. Now its gone.

Short version:

Well, i think i've got you wrong. Problem is above 800 rpm; thought it is below 800 rpm.

Flywheel generates an alternating voltage signal by each teeth of the flywheel (magnetic field). Also it generates a peak every 360 degrees. Don't put the CPS sensor closer to the flywheel, because this will cause a different alternating voltage and wobbling. So maybe a wrong flywheel - wrong amount of teeth.

I think that if the flywheel would not be installed in correct positon, the engine would not run, because Crank Shaft Position and Camshaft Position Sensor work together.

Just an idea:

If the engine runs at idle and has problems to rev up i think there are 2 factors.

The ECU didn't get a signal to turn the ignition to "early" -> Sensor problem; wrong signal
There is not enough fuel -> fuel pressure test

Did you check if the trottle body you replaced is the correct one?
Did you check if the potentiometer sends the correct voltage signal to the ECU?
Did you check if there is a correct voltage signal running from the potentiometer to the ECU?
Did you check how the sparks look like? Maybe wet?

Does the ECU throw error codes?

Wrong air: german term is "Falschluft". I'm sorry that i don't have a better translation. It means that the underpressure in the engine is troubled by a leak. Air can get in there. We call it "wrong air". Maybe someone can give me the right english term.

Thanks and regards Markus

03-17-2015, 10:05 AM	#14
Smallblock454 Registered User Join Date: Jun 2014 Location: LB, Germany Posts: 1,507	Man, wrote a long text, got logged out. Now its gone. Short version: Well, i think i've got you wrong. Problem is above 800 rpm; thought it is below 800 rpm. Flywheel generates an alternating voltage signal by each teeth of the flywheel (magnetic field). Also it generates a peak every 360 degrees. Don't put the CPS sensor closer to the flywheel, because this will cause a different alternating voltage and wobbling. So maybe a wrong flywheel - wrong amount of teeth. I think that if the flywheel would not be installed in correct positon, the engine would not run, because Crank Shaft Position and Camshaft Position Sensor work together. Just an idea: If the engine runs at idle and has problems to rev up i think there are 2 factors. The ECU didn't get a signal to turn the ignition to "early" -> Sensor problem; wrong signal There is not enough fuel -> fuel pressure test Did you check if the trottle body you replaced is the correct one? Did you check if the potentiometer sends the correct voltage signal to the ECU? Did you check if there is a correct voltage signal running from the potentiometer to the ECU? Did you check how the sparks look like? Maybe wet? Does the ECU throw error codes? Wrong air: german term is "Falschluft". I'm sorry that i don't have a better translation. It means that the underpressure in the engine is troubled by a leak. Air can get in there. We call it "wrong air". Maybe someone can give me the right english term. Thanks and regards Markus Last edited by Smallblock454; 03-17-2015 at 10:34 AM.