Robert M posted:Pat D came over to the house because we needed to swap out the alternator. The brand new alternator had some charging issues. I started the car and Pat said, "You have a clogged idle jet, can't you hear it?". There was a roughness to the idle I had previously attributed to the car being cold and it idled at an rpm level that was lower than normal, which again, I attributed to the engine being cold. Pat explained that with the idle jet clogged the engine would be idling lower than normal and the roughness to the idle was all because of the clogged jet. He felt around on the heads and could tell that one of the cylinders was not warming up due to the lack of fuel, thus no fire, and the cooler temperature. After removing and cleaning the idle jet we did all of them to be sure. There had also been an increase in popping during deceleration I had noticed. The hardest part is because although I had noticed all of this my inexperience wasn't telling me what I needed to know. Once it was all cleaned up the difference was night and day. I feel now that I know what I need to know and will notice if anything happens again.
Cleaning the idle jets is very easy and you should do that before anything else. However, if the gaskets between the carburetor and the manifold is wet you'll need to find the reason. It sounds like you have identified a possible source. Fuel leaking from there shouldn't have anything to do with the jets it should just be the loose fitting of the hose. If an idle jet is clogged it will do as I described earlier. It will cause your motor to idle rough and you will have an increase in popping on deceleration and you may experience backfiring. As I learned last year backfiring is bad.
Thanks! Wish I had Pat D as my neighbor! I would love to job shadow him building a motor... that would be an awesome learning experience!
We just got back from a nice walk, so back to the garage I go. Will pull the idle jets and give them a good cleaning (since I am in there anyways).
I'll start it up and see if I notice a rough idle. It wasn't there last weekend...