FB#1

Due to relocating, my 1980 sat for about three months with out being started. It ran fine until then. Now it misfires and smokes like a freight train. Oil smoke. The misfire I'm sure is from oil getting into the chambers.

Any ideas on where to start ?

Thanks

drwet

The big three possibilities are rings, valve seals, and intake gasket. I would start with a compression test, and a cylinder leak down test.

Fredtoo

How long have you run it?

If it's just oil that seeped past the guides, it should clear itself up.
If the gods are smiling, you won't even have to change the plugs.

calwldlife

a well seasoned motor, not a fresh rebuild should
take a 3 mos shutdown.
unless it got water logged from open weather
or leaky head gasket that took out the rings,
hard to say.

MelWff

my car sits every year for 3 months without starting, are you sure your choke is fully opening?

FB#1

Yes, manual choke.

jb78L-82

My car sits every year for many months both with the OEM motor and the rebuilt 355 L-82. 3 months sitting should not cause an issue like that........in of itself. Lots of folks park their C3's for the winter months without starting them so I suspect something else is wrong. As others have stated, rings, gaskets, valve seals, carb may be the issue....

MelWff

have you checked the PCV valve?

FB#1

Yes, it rattles.

MelWff

have you removed the spark plugs to see if they are oil fouled?

Big2Bird

I'll give you a long shot. If the pump diaphragm leaked, you could have had fuel drain into the sump. That would raise the oil level and would do it. Have you checked the oil level?

FB#1

Actually just changed oil, still smokes.

calwldlife

guess i would try to unstick a ring or 2 with some snake oil
stuff.

maybe run it at 2k to reseat rings, IF ONE DIDN'T BREAK
from rust.

you are in a tough position.
at least do some tests to make sure running it isn't making a cyl
unusable from gouge and scratch from rings being broken.

if you didn't oil the cyl and turn over by hand before the start
hard to know or guess

calwldlife

did you check pcv?

Big2Bird

Long shot #2. Is it an auto?

MotorHead

My first guess would be valve guides, however if left for a short period of time it would smoke at startup and after a minute or two the smoke goes away.

Does the smoke go away after running for a few minutes ?

derekderek

As bigbird mentioned, auto trans? 400 uses vacuum modulator? Diaphragm pops, vac will suck atf and smoke like a chimney.

calwldlife

hope it is the modulator.
for his sake.
3 mos shouldn't cause anything.
too many threads about non started engines to
know what is up.

sassc3

maybe just the fuel stabilizer need to be run out...new fresh gas...

derekderek

If valve seals all died, it would smoke bad but clear up pretty quick. If rings stuck, it woulda cranked really hard at first.