Erratic idle. Help diagnose with video
02-19-2017, 09:31 PM
#16
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This is the best picture I have:
03-03-2017, 02:53 PM
#17
Racer
Thread Starter
Thanks all, I think I will follow that advice and just replace it as my CPS was disintegrated as well as knock sensor. Mechanic did not mention this particular harness.
03-03-2017, 06:59 PM
#18
Team Owner
your engine does not have a knock sensor
03-03-2017, 08:23 PM
#19
Three Wheelin'
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In general, lean gets better when warm, and rich gets worse when warm.
On the other hand, a vacuum leak, like one of those little hard lines not being reconnected, or being swapped, or getting broken during all the excitement, would cause the engine to get unmetered air without matching fuel. This may be more noticeable when starting hot because the ECU isn't adding a whole bunch of fuel that's needed when cold. Have you noticed any other problems since this started, like maybe hard shifts (if the vacuum modulator line was disconnected) or HVAC flaps not switching correctly (if the HVAC vacuum line was disconnected)?
In general, I'd recommend double-checking all those vacuum lines. You can also try waving an unlit propane torch around various parts of the intake and hoses, to see if the engine is sucking in air. If it is, the idle will change when it sucks in fuel (propane) instead.
On the other hand, a vacuum leak, like one of those little hard lines not being reconnected, or being swapped, or getting broken during all the excitement, would cause the engine to get unmetered air without matching fuel. This may be more noticeable when starting hot because the ECU isn't adding a whole bunch of fuel that's needed when cold. Have you noticed any other problems since this started, like maybe hard shifts (if the vacuum modulator line was disconnected) or HVAC flaps not switching correctly (if the HVAC vacuum line was disconnected)?
In general, I'd recommend double-checking all those vacuum lines. You can also try waving an unlit propane torch around various parts of the intake and hoses, to see if the engine is sucking in air. If it is, the idle will change when it sucks in fuel (propane) instead.
Last edited by SQLGuy; 03-03-2017 at 08:45 PM.
03-03-2017, 08:41 PM
#20
Race Car
I didn't double check, but I'm very confident that the switch, harness and good guidance are here..
http://scott-yoo.com/other/intake.html
Thank you, Scott!
As a member of the knucklehead squad I'll just add- your found two sealing O-rings for your MAF, right?
http://scott-yoo.com/other/intake.html
Thank you, Scott!
As a member of the knucklehead squad I'll just add- your found two sealing O-rings for your MAF, right?
03-06-2017, 01:22 PM
#21
Racer
Thread Starter
03-06-2017, 01:27 PM
#22
Racer
Thread Starter
In general, lean gets better when warm, and rich gets worse when warm.
On the other hand, a vacuum leak, like one of those little hard lines not being reconnected, or being swapped, or getting broken during all the excitement, would cause the engine to get unmetered air without matching fuel. This may be more noticeable when starting hot because the ECU isn't adding a whole bunch of fuel that's needed when cold. Have you noticed any other problems since this started, like maybe hard shifts (if the vacuum modulator line was disconnected) or HVAC flaps not switching correctly (if the HVAC vacuum line was disconnected)?
On the other hand, a vacuum leak, like one of those little hard lines not being reconnected, or being swapped, or getting broken during all the excitement, would cause the engine to get unmetered air without matching fuel. This may be more noticeable when starting hot because the ECU isn't adding a whole bunch of fuel that's needed when cold. Have you noticed any other problems since this started, like maybe hard shifts (if the vacuum modulator line was disconnected) or HVAC flaps not switching correctly (if the HVAC vacuum line was disconnected)?
Based upon Mr. Merlin's suggestions and other things I have read, it seems I have blown dampers because I found fuel laying in the air intake valley this weekend. I guess the upgraded S4 regulator proved too much for the old dampers? IDK but I will be replacing those now.
The other issue suggested that I am acting on is the pigtail at the throttle body. It was suggest that it was disturbed in all the "excitement."
04-01-2017, 09:41 PM
#23
Racer
Thread Starter
Update: solved idle problem. I replaced both front and rear dampers. Bought throttle body harness plug from Roger and replaced that too. Now the hot starts are cured and idle is back to normal.
Still need to test MAF and replace O2 sensor as maintenance part.
Still need to test MAF and replace O2 sensor as maintenance part.
Last edited by 95carrera; 04-02-2017 at 12:15 PM. Reason: Spelling
04-02-2017, 11:24 AM
#25
Team Owner
Keep Em Flyin!
04-10-2017, 05:58 AM
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04-10-2017, 09:11 AM
#28
Racer
Thread Starter
