Stalls at Idle
Thread Starter
Cruising
Joined: Aug 2005
Posts: 12
Likes: 0
From: Ohio
Stalls at Idle
Hello, My '79 automatic idles rough because of an intermittent miss-fire. I believe it miss-fires because the tachometer needle drops and the exhaust sound changes at that instant. The miss-fire get worse once the engine gets hot and I have to place the transmission in neutral at red lights to keep the engine from stalling. I've replaced the spark plugs, air filter, distributor cap, and distributor rotor. Any ideas what could be causing the intermittent miss-fire? What should I replace next? Any diagnostic tips? Thanks.
Melting Slicks
Joined: Mar 2008
Posts: 2,023
Likes: 6
From: Austin Tx
Also, you can look for loose, or frayed electrical connections. A bad connection will generate heat, and the heat will mean greater resistence.
I had a problem with the cloth covered wire that goes from the starter solenoid, to the coil. At the starter this connection was very frayed. The car would start fine, and run great until it got hot. The bad connection was causing that wire to heat up, and the heat was causing increased resistence at the coil, which eventually led to weak spark, and eventually not running at all. After it cooled down, it would run fine, until it got hot again.
I had a problem with the cloth covered wire that goes from the starter solenoid, to the coil. At the starter this connection was very frayed. The car would start fine, and run great until it got hot. The bad connection was causing that wire to heat up, and the heat was causing increased resistence at the coil, which eventually led to weak spark, and eventually not running at all. After it cooled down, it would run fine, until it got hot again.
Melting Slicks
Joined: Sep 2010
Posts: 2,936
Likes: 2
From: Enraging liberals everywhere. Ocala,FL
I had a similar problem with the rough idle and miss when the motor got warm. It was nothing more than a vacuum line that was off. I hope your problem is as easy to fix.
