Main Menu

1997 993 C4S charcoal cannister - REVISED more info

Fuel System

Vehicle Information: Year: 1997; Body Type: Coupe; Total Mileage: 20000;

I have a rough idle which has defied diagnosis by multiple mechanics. No fault codes were found, compression and leakdown tests were normal, PCNA says the car is not subject to the wiring harness recall. Exhaust analysis shows unburnt fuel in the exhaust. The Bosch hammer has been used. The intake manifold was found to be good, several boots and fittings were tightened with some improvement in the rough idle. My current mechanic found a charcoal cannister saturated with fuel; what could cause this? I have read that there is a solenoid valve on a line from the cannister and this valve is controlled by the engine DME. Could a bad DME cause a saturated cannister? Could a saturated cannister cause a rough idle? My mechanic also recommended replacing my K&N filter because he said the oil from the filter could be fouling the mass flow air meter. Have you seen this problem with K&N filters ?As the mystery unravels I will let you and your readers know any answers I find.I appreciate any input you can give.

You must log in to view answers associated with technical questions. Join PCA to participate in our community.
No votes yet