Forcing Open Loop
Thread Starter
Instructor
Joined: Oct 2008
Posts: 190
Likes: 4
From: Sonora CA
Forcing Open Loop
94 LT1
I seem to spend a lot of time chasing Gremlins in the sensors (MAF, MAP, O2, IAC). However, right after it starts and is running in open loop, it's smooth as glass. The pre-programmed settings work pretty well.
Is there a way to force the engine to run in open loop all the time? Is this a good idea?
Just curious.
- WPK
I seem to spend a lot of time chasing Gremlins in the sensors (MAF, MAP, O2, IAC). However, right after it starts and is running in open loop, it's smooth as glass. The pre-programmed settings work pretty well.
Is there a way to force the engine to run in open loop all the time? Is this a good idea?
Just curious.
- WPK
Drifting
Joined: May 2013
Posts: 1,736
Likes: 31
From: Reno Nevada
Disconnect the O2's and it'll stay open, but I'm with Xmoto on this. Clearly you have a problem and you need to find the fault. Have you ohm'd the injectors. If there original it is a great place to start.
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
I'd have it in hot idle when it is acting up and start datalogging and seeing what the sensors are saying. Are they giving you plausible values? For instance, if the intake temp says 130 degrees, no. If your ambient air temp is 80 and it is around there, fair enough. Coolant temp can be verified by an infra red thermometer.
Thread Starter
Instructor
Joined: Oct 2008
Posts: 190
Likes: 4
From: Sonora CA
OK you caught me ...
94 LT1
I seem to spend a lot of time chasing Gremlins in the sensors (MAF, MAP, O2, IAC). However, right after it starts and is running in open loop, it's smooth as glass. The pre-programmed settings work pretty well.
Is there a way to force the engine to run in open loop all the time? Is this a good idea?
Just curious.
- WPK
I seem to spend a lot of time chasing Gremlins in the sensors (MAF, MAP, O2, IAC). However, right after it starts and is running in open loop, it's smooth as glass. The pre-programmed settings work pretty well.
Is there a way to force the engine to run in open loop all the time? Is this a good idea?
Just curious.
- WPK
Just was looking for a quick and easy way to get out of getting mucky this weekend.
Busted.
- WPK
Team Owner
Joined: Jul 2004
Posts: 28,331
Likes: 3,245
From: Hartford WI
If you are going to do it, do it right and do it once. Assuming it is like the L98, take the IAC off, take the top cover plate off and take the IAC housing off. Probably have to take the TB off to get it it easily. Clean everything and spray brake cleaner into the passages. GENTLE spray on the pintle and wipe it clean. New gaskets.
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Drifting
Joined: Mar 2008
Posts: 1,797
Likes: 422
From: Denver CO
I'd say bad ECM. Same thing w/my 84.Ran great in open loop but when warmed up and went into closed loop it would act up.Threw no codes.Replaced all sensors and some, same.Replaced ECM Runs great now. I opened the old ECM and found some parts of the traces had lifted from the board.
Instructor
Joined: Dec 2016
Posts: 169
Likes: 15
From: Toledo Ohio