idle speed control/EEC problems

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Jun 23, 2002 | 06:49 PM

brown 4x4

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From: Nebraska

idle speed control/EEC problems

I've spent two afternoons now trying to get this figured out. The symptoms are: When driving, when I let off and/or push in the clutch as in coming to a stop sign, it will hold a high idle for about five seconds before dropping down. It will do this if I rev it in neutral also. The "low idle" is also too high, and I can't get that to work either.

My real question is this. I'm pretty sure I have it narrowed down to the computer itself :-( . Can just one area of the computer go bad? The truck runs like almost perfect other than the idle problems. If I do need a new computer, is it worth it to get one from Ford or will a cheaper one (NAPA?) work? Even those aren't exactly cheap. Thanks for any advise.

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[font color="green"]1995 F-150 Supercab XLT longbed 4x4 302 M5OD [/font]31x10.50's
[font color="green"]1986 F-150 4x4 300 I6 NP435 [/font]Warn hubs, DeeZee bed caps, '96 XLT bench seat, new paint job

Jun 23, 2002 | 09:37 PM

DrFord

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idle speed control/EEC problems

I believe that you are getting ahead of yourself. I seriously doubt that you need a new computer.

try taking off and cleaning your idle air control valve(IAC).

in case you aren't familiar with it, it is what controls the idle speed of your engine. sounds like it make have a piece of "junk" trapped in it and that is not allowing it to completely close.

the IAC valve is on the top of your throttle body. just follow the hoses from your air filter untill the connect to the intake. the IAC valve is right there on top. it is a cylinder shape and is held down by two screws. it also hasd an electrical plug on it. just unplugg the wires then unscrew it.

on the bottom there are two holes with a sliding piston inside. just take some heavy cleaner(I use brake parts cleaner, or gun cleaning solvent will work) and a toothbrush and clean it out good.

try this and if it doesn't help, it may be your TPS(Throttle Position Sensor). if need be post a reply and I can help you with it too.

Jun 23, 2002 | 10:27 PM

brown 4x4

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From: Nebraska

idle speed control/EEC problems

Sorry, I should of mentioned it's a feedback carb, not EFI, so it has the dc motor instead of an IAC. The TPS is fairly new too.

I have the 1986 engine and emission diagnosis manual. Using their pinpoint tests I determined the motor itself is ok, along with all the wiring. All other sensors should be ok, I've never had any codes show up for them in the past. Following the steps in the manual, it leads to a bad computer. I'm also thinking that's the problem, I don't know what else it could be

.

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[font color="green"]1995 F-150 Supercab XLT longbed 4x4 302 M5OD [/font]31x10.50's
[font color="green"]1986 F-150 4x4 300 I6 NP435 [/font]Warn hubs, DeeZee bed caps, '96 XLT bench seat, new paint job

Jun 24, 2002 | 04:05 AM

fahad

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Joined: Jul 2001

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From: Jeddah Saudia Arabia

idle speed control/EEC problems

Mar 30, 2012 | 08:59 PM

mfoster54

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Joined: Mar 2012

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From: ALABAMA

IDLE CONTROL AND ECM (PUTER)

My mechanic has determined I have a bad idle control solenoid and has somehow shot the puter---right now driving with a check engine light on---mechanic has disconnected the idle control---My question how do you read the numbers on the puter while it is on the truck and where is the puter actually at under the hood?

COOL DID I MENTION IT IS 1995 F-150 XLT WITH 285,000 MILES. AND HAS A 351 ENGINE----THANKS FOR THE INFO---CTUBUTIS---YOU ROCK

Last edited by mfoster54; Mar 31, 2012 at 06:38 PM. Reason: GOT A REPLY

Mar 30, 2012 | 09:56 PM

ctubutis

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Fuel Injection Technical Library » How To Run a Self-Test
Ford Ranger/Bronco II EEC-IV Testing

Mar 31, 2012 | 07:43 PM

BigBlue88

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Posts: 911

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From: Northern Virginia, USA

If the conputer is the culprit, open it up and replace the electrolytic capacitors. Chances are good they are dry and defunct after decades of high temperature operation.