Smoke and Rough Running After Sitting

[Avanti]

77 911s 2.7. Engine runs very well (was) and uses virtually no oil. Has typical minor leaks but does not smoke. CIS gone through recently and passes CA smog easily. Positive oil is not overfilled.

Car sat for 5 days, Went out and started it and ran fine. Sat for 10 days and felt like it was running on 4 cylinders. Lots of blue smoke from tailpipe and liquid oil spitting too. Figured plugs were oil fouled so changed them. Runs a little better but still not hitting on all 6.

This car has sat before for weeks and worst case is a moderate cloud of smoke that lasts maybe 30 seconds and the engine never runs rough. I've read the posts about valve guides leaking oil into the cylinders from sitting and oil in the exhaust from sitting but never experienced this. No noises and otherwise the engine seems OK.

Should I just drive it?

Paul

[Joe Bob]

Techron and a drive.....

[geoff_k]

Hi,

When you leave an older Porsche sit for a while oil can leak into the exhaust and cause a lot of smoke. I went to pick my car up finally from a Panel Beater and then spent 30 mins driving around that area trying to clear the smoke as I was sure I was going to be pulled over by the police. Clouds of it. I am sure if you search on this site for smoke and exhaust you will find a technical explanation for the smoke.
geoff

[Avanti]

Thanks and understand the smoke part but the not running well is a little strange. Only sat for 10 days and it has sat for much longer with no issues.

Going to check the basics, fuel, ignition, etc. Old cars will break down.

Thanks!

Paul

[wayner]

Oil Soaked spark plug?

Or maybe gunned up fuel in part of the injector system?

With crappy new fuels I almost think of 10 days sitting as long term storage nowadays