high idle
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high idle
I have a 86 300 six. YFA Carter feedback carb. new ecm,longblock,rebuilt carb,new cat., new O2 sensor, EGR, TPS, Temp sensor, . All check within spec with multimeter. Getting 20MPG. Smooth idle and good power thru the curve.
At idle, the idle control soleniod stays fully extended (1600 RPM)cold or hot. At about 2500 RPM it retracts.
Took the ICS off. Disconnected one sensor at a time: same response from ICS.
What signal imputs to the ECM cause it to signal the ICS?
At idle, the idle control soleniod stays fully extended (1600 RPM)cold or hot. At about 2500 RPM it retracts.
Took the ICS off. Disconnected one sensor at a time: same response from ICS.
What signal imputs to the ECM cause it to signal the ICS?
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Joined: Jan 2001
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From: Nebraska
high idle
[updated:LAST EDITED ON 07-Jul-02 AT 08:57 PM (EST)]I'm assuming you've tried setting the idle according to the emissions sticker under the hood?
Try getting the ISC to retract by running the key on engine off EEC test. The ISC is supposed to retract at the start of this test. Check these codes while you're at it and check key on engine running codes.
I also am having idle speed control problems and have spent hours and replaced parts that already worked trying to get mine to idle right. I know the ecm uses a signal from the coolant temp. sensor because unplugging it should give you a high (1600 rpm) idle. I'm not sure about other sensors though.
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[font color="green"]1995 F-150 Supercab XLT 4x4 302 M5OD 8' bed [/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
Try getting the ISC to retract by running the key on engine off EEC test. The ISC is supposed to retract at the start of this test. Check these codes while you're at it and check key on engine running codes.
I also am having idle speed control problems and have spent hours and replaced parts that already worked trying to get mine to idle right. I know the ecm uses a signal from the coolant temp. sensor because unplugging it should give you a high (1600 rpm) idle. I'm not sure about other sensors though.
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[font color="green"]1995 F-150 Supercab XLT 4x4 302 M5OD 8' bed [/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
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high idle
Thanks Justin. I checked and have 12v at the ICS. Over a month or so it gradually began to hang up at high idle at stops and now it just stays there. Runs great with the ICS off the carb except for the morning start up - have to keep my foot on the pedal until it heats up some.
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high idle
Thanks for the pointers. Yes, the carb used to tune OK using the set up procedure on the hood sticker. Disconnect the temp sender, set ICS adj. screw to 1600RPM and the ICS worked fine. Over a month or so the ICS started to hang at high idle and then it stays there all the time when I stop. I took the ICS off the carb to physically check the unit(truck runs great without it) and found that at 2500RPM the plunger retracts completely and at idle you can feel the signals from the ECM step the plunger out. Disconnecting the temp sensor does not change the ICS position now: high idle at stop/retracted at speed. Cold start up is the same. Stays the same with the key in the engine off position. I dont own an error code unit, was hoping not to have to go to that expense, but that looks like the next step. Where do you hook it up?
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Joined: Jan 2001
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From: Nebraska
high idle
You don't need anything but a test light or voltmeter and jumper wire to read the codes yourself. The connector should be on the passenger side right behind the battery. This site goes into detail about how to do it:
http://www.dalidesign.com/hbook/eectest.html
I've been thinking about how it works and I think the temperature sensor is the only one that tells the ecm to adjust the idle. You may have a short or bad connection somewhere in the ECT circuit saying the engine's always cold and giving you a constant high idle. That's the only thing I can come up with as I've spent so much time studying the system trying to get mine to quit "hanging" at 1200 rpm for a few seconds when I stop.
Good luck with yours. :-)
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[font color="green"]1995 F-150 Supercab XLT 4x4 302 M5OD 8' bed [/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
http://www.dalidesign.com/hbook/eectest.html
I've been thinking about how it works and I think the temperature sensor is the only one that tells the ecm to adjust the idle. You may have a short or bad connection somewhere in the ECT circuit saying the engine's always cold and giving you a constant high idle. That's the only thing I can come up with as I've spent so much time studying the system trying to get mine to quit "hanging" at 1200 rpm for a few seconds when I stop.
Good luck with yours. :-)
--------------
[font color="green"]1995 F-150 Supercab XLT 4x4 302 M5OD 8' bed [/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
