'86 Idle control valve not functioning
09-23-2014, 06:48 PM
#1
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'86 Idle control valve not functioning
Good afternoon all,
Newly noticed issue with the 928. My ICV although fairly new seems to have stopped functioning. This morning it was a little colder than it has been recently and when I went to start the car it took several tries to start, it was starting and immediately dieing. After a few tries I had to start it with the throttle cracked open and hold the throttle open for around 15 seconds for it to start idling. It then had an extremely low idle ~500 rpm until it had warmed up a little.
I didn't have time to play around with it then but I just got a chance to look at it and jumping the B&C pins on the test plug doesn't effect the idle at all. Are there any other ways to test if the ICV is working?
Thanks
Eddie
Newly noticed issue with the 928. My ICV although fairly new seems to have stopped functioning. This morning it was a little colder than it has been recently and when I went to start the car it took several tries to start, it was starting and immediately dieing. After a few tries I had to start it with the throttle cracked open and hold the throttle open for around 15 seconds for it to start idling. It then had an extremely low idle ~500 rpm until it had warmed up a little.
I didn't have time to play around with it then but I just got a chance to look at it and jumping the B&C pins on the test plug doesn't effect the idle at all. Are there any other ways to test if the ICV is working?
Thanks
Eddie
09-23-2014, 07:12 PM
#2
Team Owner
check the fuses. spray deoxit on the fuse pins.
The ISV is a wear item in your year of system,
the only other way to verify its function is to remove it,
then use a pick to see if the armature turns freely.
NOTE if its worn then the armature/shaft will stick,
the stick is caused by the brushes wearing holes into the armature,
thus they will grab the armature and prevent it from moving
The ISV is a wear item in your year of system,
the only other way to verify its function is to remove it,
then use a pick to see if the armature turns freely.
NOTE if its worn then the armature/shaft will stick,
the stick is caused by the brushes wearing holes into the armature,
thus they will grab the armature and prevent it from moving
09-23-2014, 10:58 PM
#4
Team Owner
any chance that you might have swapped the ISV plug for the air cleaner temp sensor plug?
The ISV plug gives 12V,
the temp sensor gives about 5V.
NOTE if they are swapped the temp sensor in the air cleaner housing will be fried.
NOTE if switching the test port does not change the idle, then you have an issue with,
the ISV,
the power supply to the ISV ,
or the computer has been damaged .
NOTE computer damage is not a very common issue, but it does happen,
this can be tested by installing your computers into a known good running car,
then using the test port to disable the idle circuit
The ISV plug gives 12V,
the temp sensor gives about 5V.
NOTE if they are swapped the temp sensor in the air cleaner housing will be fried.
NOTE if switching the test port does not change the idle, then you have an issue with,
the ISV,
the power supply to the ISV ,
or the computer has been damaged .
NOTE computer damage is not a very common issue, but it does happen,
this can be tested by installing your computers into a known good running car,
then using the test port to disable the idle circuit
09-23-2014, 11:15 PM
#5
Drifting
any chance that you might have swapped the ISV plug for the air cleaner temp sensor plug?
The ISV plug gives 12V,
the temp sensor gives about 5V.
NOTE if they are swapped the temp sensor in the air cleaner housing will be fried.
NOTE if switching the test port does not change the idle, then you have an issue with,
the ISV,
the power supply to the ISV ,
or the computer has been damaged .
NOTE computer damage is not a very common issue, but it does happen,
this can be tested by installing your computers into a known good running car,
then using the test port to disable the idle circuit
The ISV plug gives 12V,
the temp sensor gives about 5V.
NOTE if they are swapped the temp sensor in the air cleaner housing will be fried.
NOTE if switching the test port does not change the idle, then you have an issue with,
the ISV,
the power supply to the ISV ,
or the computer has been damaged .
NOTE computer damage is not a very common issue, but it does happen,
this can be tested by installing your computers into a known good running car,
then using the test port to disable the idle circuit
09-23-2014, 11:34 PM
#6
Team Owner
Doh your right maybe i was thinking of the 84 Euro
09-24-2014, 05:11 PM
#7
Pro
Thread Starter
Join Date: Feb 2010
Location: Portsmouth VA
Posts: 505
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any chance that you might have swapped the ISV plug for the air cleaner temp sensor plug?
The ISV plug gives 12V,
the temp sensor gives about 5V.
NOTE if they are swapped the temp sensor in the air cleaner housing will be fried.
NOTE if switching the test port does not change the idle, then you have an issue with,
the ISV,
the power supply to the ISV ,
or the computer has been damaged .
NOTE computer damage is not a very common issue, but it does happen,
this can be tested by installing your computers into a known good running car,
then using the test port to disable the idle circuit
The ISV plug gives 12V,
the temp sensor gives about 5V.
NOTE if they are swapped the temp sensor in the air cleaner housing will be fried.
NOTE if switching the test port does not change the idle, then you have an issue with,
the ISV,
the power supply to the ISV ,
or the computer has been damaged .
NOTE computer damage is not a very common issue, but it does happen,
this can be tested by installing your computers into a known good running car,
then using the test port to disable the idle circuit
Where does the ISV get power from?
