Low RPM skip / moisture in valve cover

[starsnstripers]

1970 L-6 165 MC-1 OK, first between 750-1300 rpms it runs rough and skips I pulled #5+6 plug wires with no change, 1-4 did make a difference. New points, plugs, wires,cap, and rotor. when i bring the rpm up to 1400+ it smooths out. Also i noticed a drip from the vent tube on the valve cover, removed cover and it had a milky film on the rear top half of the cover. No milky on the head or around the rocker area and no milkyness in the oil. I went ahead and did a compression test and all cyl. are between 115 and 120. Seems cyl 5+6 only fire with the rpm up to atleast 1400 rpms. Any suggestions? thankyou

 

[Don S]

Re: Low RPM skip / moisture in valve cover

What did the spark plugs look like on 5 and 6 compared to the rest of the plugs.

 

[starsnstripers]

Re: Low RPM skip / moisture in valve cover

They all looked the same Don i even swaped them out with the plugs from 3-4. They are a little on the dark side but look ok.

 

[Don S]

Re: Low RPM skip / moisture in valve cover

Have you checked the firing order and made sure it's correct?

 

[starsnstripers]

Re: Low RPM skip / moisture in valve cover

Yes it's correct, Don. What do you think about the moisture build up in the valve cover?

 

[Bondo]

Re: Low RPM skip / moisture in valve cover

What do you think about the moisture build up in the valve cover?

Ayuh,... That'll be Condensate......

 

[starsnstripers]

Re: Low RPM skip / moisture in valve cover

Thanks Bondo, Now back to the running rough/skipping at low rpm ? Weak Coil?

 

[starsnstripers]

Re: Low RPM skip / moisture in valve cover

Whats odd is it seems #5+6 cylinders are the ones not firing right at low rpm. I tried some other spare wires on those two cly. too no change.

 

[Fishermark]

Re: Low RPM skip / moisture in valve cover

When you say it is not firing - do you say that because you cannot tell a difference when you remove the spark plug wire? If that is the case, have you tried to see if you have a spark at the wire? In other words, hold the end of the wire near the ground and test for a spark that way.

 

[chiefalen]

Re: Low RPM skip / moisture in valve cover

thats condensation for sure in the valve cover.did you check for moisture in the cap.how the points look.