Hey all, have had a problem for a few months now on my '93. The Idle sticks real high...even after it warms up. I have run codes and is clean. Removed the throtle body and cleaned it out. No vacuum leak. New air filter. New plugs.
Any other suggestions I have missed?

The Idle dosen't always stay high, sometimes if I gun it, it will kick down. but other times I have to shut down motor then restart. This is a real pain in butt. Starting to irk me.

Any help would be appreciated.

-----nailer-----

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ON ORDER: 2000 F250 SD SC XLT V-10 SB With all the goodies! (Due Mid-April)

CURRENT: 1993 F150 SC XLT 5.0L V-8 with 165,000 miles, (a new x-mission), and lots of great memories!

 

hmmm.The only other thing I have heard of is with the high mileage, that the actual butterfly's inside the throttle bore had some how "scribed" a groove lip that prevented the butterfly's from fully shutting, causing a high idle. They also could gun it and bring the idle down, but other than your cable and linkage on top.....Maybe the TPS or I didn't see you list the IAC valve...Have you cleaned that? Oh Pastmaster......

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1993 F-150 4x4 5.0L EFI 5spd. Silver Shortbed..Kelly Safari AWR tires,K&N Air filter,Cat-Back Exhaust. Soon to get: Improved Ignition

 

I guess Ford had too many complaints about high idles and high maintence on the early efi trucks like ours because they came out with a new part for it...I guess its around 12 bucks. Might help out.
Check this out. I haven't bought one, because I haven't had any serious problems, yet...knock on wood.
http://www.ford-trucks.com/dcforum/80_96/1472.html

 

I HAD THE SAME PROBLEM WITH MY '89, AND I HAD PUT A NEW LONG BLOCK IN AND REPLACED ALL THE SENSOR'S ON IT.

MY '91 HAS STARTED DOING THE LAST MONTH OR SO. I CLEANED ND REPLACED ALL OF THE ABOVE ON THE '89 AND STILL NEVER FIGURED IT OUT.

 

I have the same problem with my '92 302. I've been trying to figure out the problem for a couple of years now and have had no luck. I have checked the output of every sensor I can get my hands on and they are all in spec, fuel pressure is good, new IAC and MAP sensors (they had been out of spec), new plugs, cap, rotor and wires. I have read that the problem could be related to the coolant temperature sensor, but again that's in spec (although I haven't tried measuring it when the idle is surging). Since I also have a problem with the same truck running crappy when it warms up, I may just replace the sensor and see if it helps. After that, the only thing I can think of is the computer being bad or intermittently bad (or possible the cruise control starting itself up?). Since I only use the truck for hauling stuff a couple days a month it's not really a huge issue, but if I do find the answer I'll post it. And if anyone has any more suggestions PLEASE HELP! Keep in mind that this isn't just a high idle problem, because it's fixed when the engine is turned off and then turned back on again, but ONLY is fixed after the engine is turned off and on again. That doesn't completely rule out a mechanical problem, but it sure limits the possibilities. I should mention that I have a manual transmission, so I know it has nothing to do with the transmission. Any help would be appreciated!

 

I'm not sure how relavent this is to everyone elses truck it is, but i had an 85 351 with that problem, and the problem ended up being a stuck aumotmatic choke. the idle, at first, would run high untill the engine temp got to normal operating temp. then it just ran high all the time. in the end the choke was stuck.