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hunting idle... by AL87
Started on: 03-23-2014 11:03 PM
Replies: 10 (601 views)
Last post by: Lou and Blue on 03-29-2014 09:19 PM
AL87
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Report this Post03-23-2014 11:03 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
2.8 hunts up and down on idle from 900-1300 code 22
car is 86 4spd gt. acceleration is fine. slight hesitation on throttle input.
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Gall757
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Report this Post03-24-2014 07:45 AM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
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Report this Post03-24-2014 10:26 AM Click Here to See the Profile for fiero5150Send a Private Message to fiero5150Edit/Delete MessageReply w/QuoteDirect Link to This Post
I changed the IAC on my 2.8 and that fixed the problem. No more idle hunting. Ordered A/C Delco part from Rock Auto.
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AL87
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Report this Post03-24-2014 11:34 AM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
Its time to diagnose the problem. I'll definitely test the IAC and TPS. also from another recent problem I've encountered the coolant temp sensor may be out of adjustment leading to the hunting idle. but im pretty sure the code 22 (low tps signal) is just the tps, its the only code, and its on consistently.
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AL87
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Report this Post03-25-2014 11:45 AM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
as predicted, the iac was adjusting constantly creating the hunting described.
that is most likely the combination of, or either of the two sensors. (IAC, and CTS)

the code 22 being the most anoying here because it just "switched" off like theres nothing coming from the tps anymore.
even when I pull the connector going to it, and play with the throttle, it still hesitates.
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AL87
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Report this Post03-25-2014 04:12 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
I diagnosed the tps, its getting voltage. black to black for ground and red to blue for voltage. getting from .2-6.5V low-high with an analog tester.

is there any way to test somewhere for the signal to the ecm?
the motor is acting like there isnt a tps connected. so somewhere there is a break to the ecm.

that would be the grey, right?

[This message has been edited by AL87 (edited 03-25-2014).]

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AL87
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Report this Post03-25-2014 06:27 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
update, i took the center console out to get to the ecm, and I found the blue wire to the tps, it looks like it had been tampered with at one point before me.
the wire was broken and the clip wasnt in good condition when I pulled it out. the retainer was gone. will attempt to correct and update later.
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AL87
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Report this Post03-28-2014 12:53 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
Good as new.
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Lou and Blue
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Report this Post03-28-2014 07:20 PM Click Here to See the Profile for Lou and BlueClick Here to Email Lou and BlueSend a Private Message to Lou and BlueEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have the same idle hunting in my 85 GT. I got an IAC from ebay for $10.61 shipped. I haven't installed it yet though. I hope that's the issue.

------------------
===Always trying to find time to work on cars===
Louis Duet
Baldwin, Long Island, NY
Where driving hard is SOP.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Blue" <= '85 Fiero GT
Stock V6---Stock everything. Trying to keep it 'mostly' that way.
~~~~~~~~~~~~~~~~~~~~~
"Boo" <= '81 Delorean DMC-12
The "DuetLorean"
VIN #5835
Stock PRV engine
Robertson Equipped
Neiland/Delman Engineered
Carbed and loving it! (Peugot 604 manifold) ---"Sorry purists"

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AL87
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Report this Post03-29-2014 02:53 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou and Blue:

I have the same idle hunting in my 85 GT. I got an IAC from ebay for $10.61 shipped. I haven't installed it yet though. I hope that's the issue.



cross your fingers*
I diagnosed the vac lines, tps at its connector, IAC, CTS before I went to the ecm connectors.
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Lou and Blue
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Report this Post03-29-2014 09:19 PM Click Here to See the Profile for Lou and BlueClick Here to Email Lou and BlueSend a Private Message to Lou and BlueEdit/Delete MessageReply w/QuoteDirect Link to This Post
I will install my new IAC and inspect the ECM wires as well. Thank you for the tip.

------------------
===Always trying to find time to work on cars===
Louis Duet
Baldwin, Long Island, NY
Where driving hard is SOP.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"Blue" <= '85 Fiero GT
Stock V6---Stock everything. Trying to keep it 'mostly' that way.
~~~~~~~~~~~~~~~~~~~~~
"Boo" <= '81 Delorean DMC-12
The "DuetLorean"
VIN #5835
Stock PRV engine
Robertson Equipped
Neiland/Delman Engineered
Carbed and loving it! (Peugot 604 manifold) ---"Sorry purists"

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