Engine RPMs

[Ricker]

Did some checking: Battery is at 12.54 volts - engine off. Alternator at no load 13.8 volts. Alternator at load (lights, A/C) 12.89 volts. I was checking the dwell, hence fuel/air ratio. I noticed that it kept changing. Long story short, the "lollypop" is not fitting tight anymore and as it jiggles the air/fuel ratio and the dwell changes. Now just to plug the port but be able to get to it later if needed. Sealing it seemed to take care of the RPM issues. Fingers crossed I'm right.

[Rich]

I was checking the dwell, hence fuel/air ratio. I noticed that it kept changing. Long story short, the "lollypop" is not fitting tight anymore and as it jiggles the air/fuel ratio and the dwell changes. Now just to plug the port but be able to get to it later if needed. Sealing it seemed to take care of the RPM issues. Fingers crossed I'm right.

Nice sleuthing there. You've at least eliminated a potential issue without throwing parts at it.

I assume you know the lambda/mixture dwell regularly changes once the system goes into closed-loop mode. It should regularly oscillate every second or two over a range of degrees every few seconds with the average dwell value staying pretty constant.

One hack for the loose lollipop (the mixture adjustment hole plug with the looped wire handle on top) - Go to the fasteners/bolts aisle at your local Ace Hardware to find a black rubber stopper for sealing the mixture screw hole. Small enough on the pointy end to enter the hole, large enough not to fall into it.

It works like a soft tapered cork in place of the lollipop. This plugs the hole securely. Be sure not to use a stopper made of cork.

[mhanch]

I bought a pack of these: https://www.amazon.com/gp/product/B0...?ie=UTF8&psc=1

multiple sizes so I could trim one to an exact fit. then i pulled the metal pin out of the old one and stuck it into the new one. no leaks at all


and you get 40 so you have spares. Until you forget where you put the pack.....