1989 ford idle issue
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1989 ford idle issue
I have a 1989 ford f150 4x4 302 with 5 speed manual. The engine has just been rebuilt.
I'm having an issue where it doesn't like to idle down from from where you bring the idle up to unless you give it a quick rev, and then it will come down. But if the idle goes below about 900 it will begin surging. The surging starts small and slowly grows until it is revving over 1000 and dropping below 500rpm where it will kill itself.
I've replaced the IAC, the MAP sensor, and the distributor. I've searched high and low for a vacuum leak and can't find one.
I believe it has something to do with timing because if I throw a timing light on it the surging follows the advance and when the idle is high the timing is bouncing 10 or more degrees every other revolution.
thank you for reading this.
I'm having an issue where it doesn't like to idle down from from where you bring the idle up to unless you give it a quick rev, and then it will come down. But if the idle goes below about 900 it will begin surging. The surging starts small and slowly grows until it is revving over 1000 and dropping below 500rpm where it will kill itself.
I've replaced the IAC, the MAP sensor, and the distributor. I've searched high and low for a vacuum leak and can't find one.
I believe it has something to do with timing because if I throw a timing light on it the surging follows the advance and when the idle is high the timing is bouncing 10 or more degrees every other revolution.
thank you for reading this.
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it starts this as soon as you touch the throttle and doesn't really stop it unless you drive it a while, shut it off and then start it again, but it has no power after you restart it.
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From: Houston/Sugar Land
If the spout is not connected, the computer no longer controls timing. The spout should have been unplugged when it was timed to set manual base timing. Have you checked to see if is plugged in?
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the spout was in when it gave me that code, but today I tried replacing the ignition controll module, and timed it. Now the high idle issue has gone away and I just have a surging at idle. The day before yesterday I tried replacing the entire distributor and it had never run worse. I put the old one back and returned the new one as faulty.
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From: Houston/Sugar Land
Now that you have it timed would be a good time to run codes again. Be sure to post the code numbers. Run koeo and Koer test and indicate which test the code comes from.
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so first I did a computer reset where you unplug the battery for 15 mins and then run the truck for 15 mins without touching the throttle. Then since the engine was warm I did the KOER and got a code 44 "because we have the air pump delete option" and a code 24... no idea what that last one means. The KOEO test gave me a code 11.
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it said it was in the normal temparature range...
Lead Driver
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From: Houston/Sugar Land
I suggest you run codes again and see if you get the 24 code again. If so you should replace the air Charge temp sensor. The 11 code you got means that test showed no active codes for that particular
test.
test.
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so I replaced this sensor when I rebuilt the engine. Hopefully it just wasn't up to temp
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