Twisted

OK, I've discovered that my "lumpy idle" is due to an irregular miss at idle. At the risk of sounding silly: Let's say my normal idle (while kneeling down between the pipe tips) sounds like buh-buh-buh-buh-buh, etc. Well with the miss, it sounds like buh-buh-buh-buh-tap, buh-buh-buh-buh-buh-tap, buh-buh-tap, etc. The tap is very subtle, and sounds like if you let some pressure build up behind your lips, and then open them. Silly stuff, I know; I'm just trying to paint a good picture. Any thoughts on what's causing this?

FiveLiterRiceEater

my buddy had something like that happen to his 79 monte carlo, it turned out be to a plug wire shorting to his header. make sure none of your wires are arcing onto anything. what i do is spray them with water, with the car off. then start it and see if it goes away. dont spray the wires with the car on though, you'll shock yourself pretty good...and that hurts.

Twisted

Thanks, fiveliter. It does sound like that may be what it is--electrical shorting. I'm surprised though because it was doing the same thing even before I changed my wires and plugs, and hasn't changed since. You can hear it under the hood when it happens; it sort of sounds like someone is sitting inside turning the air conditioner on and off, although not that drastic. Has anyone else experienced this?

FiveLiterRiceEater

i had something similar but it was before i replaced anything. one of my plugs was carbon fouled really bad. but you could really feel it had a dead cylinder. i ended up replacing plugs and wires and mhy pcv valve and havnt had any problems since. yours though probably wont be like that. check your distributor cap for cracks, make sure none of your wires are touching etc. you may just have a bad wire that has too much resistance in it thats not letting the full spark get to the plug.

black89gt

my car does the exact same thing, but it runs strong when driving.. wierd.. i know my harmonic balancer is bad cause i see it wobbling so i neeeda change that.

5.0stanger

A new cap and rotor will run ya about 20 bucks, try that maybe since you already have new wires and plugs.

Twisted

Thanks for the replies everyone. I did the cap and rotor, wires, and plugs almost at the same time, and it made ZERO difference. Crazy. I'm half considering letting some half-cocked mechanic grope the car, and see if he can figure out what it is; I'm just trying to avoid such foolishness. At any rate, thanks again.

Twisted

Yeah, mine runs perfect at any rpm above idle, and pulls like a champ. Such a strange little problem.

PRO50SC

Sometimes it comes to that. They're not all idiots you know!!

Twisted

True indeed. I've just been surprise at how sometimes mechanics know less about something than I do. And I've almost laughed at some things said by certain motorcycle mechanics I've known. But true, there are many that know their sheeot. Maybe I'll get lucky and find one.