996 Engine Problems

Elfer · 04-20-2008, 08:34 AM

I posted this at the 996 forum but I'm not getting any replies so I thought I'd try here. Well, I recently swapped my 996 engine for a low mileage engine I bought from a local P-car shop in NY. Got it started but ran into some problems. The car has a definite miss eminent from the left exhaust (which means the miss is coming from the right engine bank). Compression is about 125-130 on all cylinders except on in the right engine bank which is registering 100. All plugs have a very clean burn and no oil fouling. I can definitely smell the car is running rich on the left exhaust. When revved in higher rpms, smoke comes out and the check engine light starts to flash. At idle, the CEL is steady.
I would have to get an OBDII reader to get the codes. If the smoke is from burning oil, shouldnt the plugs be fouled? Any input is greatly appreciated.
Thanks.

D'STARGA · 04-20-2008, 08:46 AM

Elfer, You will need to perform a leakdown on that low cylinder to find out what is causing that low compression. And you will need to get the code reader to find out what codes you are throwing to be able to solve this problem. Are the motors/computers compatable for your application? I would start with the leakdown to figure out why you have low compression then find out what codes you have. Hope this helps.

Elfer · 04-20-2008, 07:32 PM

*Update*
The engine miss turned out to be a bad injector so the car is running fine now except for a slight trace of smoke, possibly running rich. The CEL is now gone and hasnt reappeared, but without any error codes I can't determine the cause of the smoke. I might add that there is no smoke at start up and no smoke at idle, but appears after a spirited drive. Could this be just the engine clearing itself out after years of storage? I did notice that the amount of smoke has diminished over time and is now a faint trace and hardly detectable. My only concern is passing smog with an engine running too rich.

Wayne 962 · Wayne 962's Garage

Get yourself the Durametric tool / reader for these cars - it's definitely worth it at $250. That will tell you exactly what is going on and what needs attention...

-Wayne