85 CFI uneven idle

[85 Town Car]

My 85 LTC doesn't seem to idle right when it's warm. If I start it up in park, it will idle just fine and it drives fine, but after driving fine, I'll pull into a parking spot and it's idling fine, but once I put it into park, the idle is really uneven, like it cycles from somewhere in-between 500-1000.

Any ideas?

[ford man]

You might want to check your fuel injectors with a timing light. With your timing light hooked up and the car running you can check if your injectors have a good spray pattern. If they don't, you can try adding injector cleaner for a few tanks of gas or replacing injectors if thats your problem.

Or it could be something with your EGR valve, but I'm betting injectors

Isaiah

[gadget73]

When was the last tuneup? How old is the fuel filter? Have you replaced the vacuum lines? Usually doing that stuff fixes a lot of the CFI demons. Sometimes it will give you useful codes too, but I wouldn't count on it.

[85 Town Car]

I did a tune-up (plugs, wires, cap, rotor, air filter, breather filter, the oil cap/pcv valve, a good spray down of the throttle body with throttle body cleaner and a Seafoaming) in May, which was about 3000 miles ago.

[Juhana N]

Hey mangs, my Ž83 Country Squire w/CFI idles actually pretty smoothly on cold engine. When hot, idle becomes uneven, it travels up & down a bit all the time. Gonna do some tune-up but IŽd like to have an opinion about what I should check first.

[gadget73]

Check the vacuum lines. Leaks will cause idle problems. A bad oxygen sensor could also contribute to this, but maybe not.

[85crownHPP]

Mine did that too... I just rigged my throttle stepper solenoid to a switch so I had manual control of about 500 rpms at idle. I just flipped the switch when it started to act funny, so it at least wouldn't stall out.