Code P1579 on replacement engine...
 

I replaced 3.2 engine in my '02 Boxster S with a used 3.2 from the same model year and just got it running and everything seemed in order during my first test runs. Initially, I was not pushing the engine to make sure everything was connected right and all seemed in order. This weekend I tried to open it up a little bit and discovered that the engine cuts out at about 4000 RPM. It starts spitting and sputtering and will not rev to 5000. The symptoms reminded me of bad MAF's I suffered in the past. I checked the codes and it showed a P1579 or Crankshaft Position Sensor. I cleared the code and so long as I keep the RPM's under 4000 it stays clear. The engine runs perfectly up to 4K, is highly responsive and smooth. I can hold the accelerator at 4K and it runs fine, push to 4200 and the spitting starts. If I push it hard trying to achieve 5000RPM, it throws the P1579 code.

I replaced the Crankshaft Position Sensor with the one from my blown engine. That engine was running perfectly until it threw a rod through the top of the case. Same result, spitting and sputtering at 4200 RPM. I then took out the MAF sensor and cleaned and reinstalled it. FYI, that MAF is less than a year old and probably has fewer than 5000 miles on it. It is the one that was in the car when the engine blew, and as I previously stated, it was running fine. I tired running the engine with the MAF disconnected. It still would not rev to 5000 with the spitting starting around the same RPM's. I checked the codes after that run and had P0102 (MAF input) and P1579.

A bit more info, I upgraded the IMS bearing to the LN Engineering, and upgraded the flywheel to the Aasco aluminum version with a new SPEC clutch disk and pressure plate. I am at a loss. HELP

As the crank position sensor reads from the flywheel, and you have a new aftermarket flywheel, I'd start there. Perhaps you should contact the manufacturer.

This is my worst fear, hate to go back in to the tranny! I was hoping since it was running so well up to 4K that someone might be able to rule out the ring on the flywheel.

The ring is acutally on the back of the crank, near the pilot bearing the nose of the tranny fits into. If the crank sensor checks out OK, the next stop has to be the shutter wheel............

Found the problem....It seems the vendor that I bought the Aasco flywheel from either sent me the wrong unit, or it was damaged in shipping. Either way, here is a pic of the damage it is doing to the Crankshaft Position Sensor. Looks like the shutter wheel teeth are making contact with the sensor. It is gouged pretty good. So out comes the tranny! YEA!

http://i271.photobucket.com/albums/j...a/CIMG0304.jpg

don't pull the tranny. try to ID the bad shutter finger through the hole where the crank sensor goes. bend it back in place through the hole.

alternative: shim the crank sensor out a couple of millimeters so it clears the shutter wheel.

FYI, i have an extra crank sensor you can have.