Shorts & weird idle

[Anonymous]

Finally got the tranny in and homebrewed clutch cable set-up done (enough).

It goes under it's own power again for a short trip around the block. But now it's acting funny.

Two thing, and I'm not sure if they're related or not.

Symptom 1: With battery connected, and ignition off, there is an occasional discharge from somewhere. There's and audible tick/buzz at the same time the ammeter reads a quick jump to the "discharge" side of the gauge. Short someplace? Bad solenoid? Bad ignition switch?

Symptom 2: Once warm, the idle is very poor. It drops to almost-dead, then *whoomp* back up to a reasonable idle speed. This is a regular event on about a 1-1.5 second interval. Carb issue? Ignition issue related to the electrical problem in Symptom 1? Not very clueful right now.

Any voice of experience or advice on either of these? Never seen this before.

I think the gas is fresh enough. Been sitting for a few months. Carb is rebuilt, but no guarantees of how well it was done. I checked float level, and it looked okay. Bad at diagnosing carbs, so I'm not counting my opinion on the float as reliable. No clue at all on Symptom 1. I've got the battery disconnected for now.

--mikey

 

[pedal2themetal45]

HI YA
Boy on the electrical I'm not sure... What might help find the prob is hook up the battery and start pulling fueses and see when it stops making noise or the discharge.. That shold narrow it down. Not sure you don't say what your working on??
As for the carb.. lets see..
Float level... If its attached to the top of the carb pull the top off and invert it the float should set level (horazonaly) the the top of the carb (same distance from the top at the needal and seat as at the end of the float).Or just tipped down a little at the end..
If it is attached to the inside of the carb. Unhook the coil wire (so it won't start) Pull the top off. hold down on the pin on eather side of the float and crank the motor over so the pump well pump gas and see how full it gets (shouldn't get much over 1/2 - 3/4 full).
Next (or even first) would be to check the Idle screw. Again not sure what carb you have. On some the idle screw is also the fast idle screw and it may just need to be adjusted for idle when at running temp and the choke is off. (if this is the case you well have to readjust the choke so the motor won't idle to fast when cold not the screw).
Then lastly would be the Air/Fuel mixture screw. (the screw in the base of the carb.) If you screw it all the way in (GENTLY) the motor should die.(if it don't then there is a vacuum leak somewhere or the idle speed it to fast). Back it out 2 turns. run motor to running temp. then adjust the screw in/out (a little goes along way) to find best (smoothest) idle. the readjust idle. Check timming.
hope this helps
Tim

 

[Anonymous]

Sorry. I sort of negelected some of the info there. Need to readjust that telepathic interface....

Car= '67 Mustang with 200
Carb= Autolite 1100. The original carb, near as I can tell.

Thanks for the fuse idea. That could help narrow things a lot. I'll update nexy time I work on it. I'm moving this week, so I she's on the back burner for now.


--mikey

 

[Anonymous]

Also check the fuel pump.

 

[Anonymous]

Does the ammeter bounce when the idle is surging? If so, then it may be electrical as if the regulator is cutting in and out of a fault.

The surging could be a result of some gunk in the carb. You might try to poor boy it and squirt cleaner down all the orifices you can see, and then add a bottle of carb cleaner to the fuel.