1990 runs rough, will not start after warm
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 1,210
Likes: 1
From: fighter pilots make movies, bomber pilots make history
1990 runs rough, will not start after warm
I have a 1990 with 40,000 miles. Starts easily when cold. After running few minutes idles rough, then detonates when warm (not hot 200F).
While warm will NOT start. Fuel pressure correct.
O2 sensor voltage within limits but seems to swing quite abit.
Pulled codes with scanner while cool on start-up and then again after the hot problem, but no codes, hot or cold.
I am thinking MAP or Mass air flow, but just not getting the code 33 or 34 as FSM suggests. Any suggestions which one is maybe more likely?
Any alternative suggestion
many thanks
Joe
While warm will NOT start. Fuel pressure correct.
O2 sensor voltage within limits but seems to swing quite abit.
Pulled codes with scanner while cool on start-up and then again after the hot problem, but no codes, hot or cold.
I am thinking MAP or Mass air flow, but just not getting the code 33 or 34 as FSM suggests. Any suggestions which one is maybe more likely?
Any alternative suggestion
many thanks
Joe
Last edited by devildog; Jun 19, 2009 at 11:23 PM.
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
I have a 1990 with 40,000 miles. Starts easily when cold. After running few minutes idles rough, then detonates when warm (not hot 200F).
While warm will NOT start. Fuel pressure correct.
O2 sensor voltage within limits but seems to swing quite abit.
Pulled codes with scanner while cool on start-up and then again after the hot problem, but no codes, hot or cold.
I am thinking MAP or Mass air flow, but just not getting the code 33 or 34 as FSM suggests. Any suggestions which one is maybe more likely?
Any alternative suggestion
many thanks
Joe
While warm will NOT start. Fuel pressure correct.
O2 sensor voltage within limits but seems to swing quite abit.
Pulled codes with scanner while cool on start-up and then again after the hot problem, but no codes, hot or cold.
I am thinking MAP or Mass air flow, but just not getting the code 33 or 34 as FSM suggests. Any suggestions which one is maybe more likely?
Any alternative suggestion
many thanks
Joe
Bad injector coils will not throw a code. report your findings
Heel & Toe
Joined: Jun 2009
Posts: 24
Likes: 0
From: ashland Kentucky
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 1,210
Likes: 1
From: fighter pilots make movies, bomber pilots make history
get an ohm meter and check the coils on each injector. Normal is 16ohms.. Under 12 they are going. under 10 they are shot.
Bad injector coils will not throw a code. report your findings[/QUOTE]
Thanks Jon, will try this. Injectors were my early thought. But since it is temperature related and same problem if driven on street or warmed at idle, thought sensors
Will report
Joe
Bad injector coils will not throw a code. report your findings[/QUOTE]
Thanks Jon, will try this. Injectors were my early thought. But since it is temperature related and same problem if driven on street or warmed at idle, thought sensors
Will report
Joe
Last edited by devildog; Jun 20, 2009 at 12:13 AM.
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Joined: May 2007
Posts: 82
Likes: 1
From: LA California
Thread Starter
Burning Brakes
Joined: Oct 2004
Posts: 1,210
Likes: 1
From: fighter pilots make movies, bomber pilots make history
I think you have it. i just checked the injectors all good (16.5+) except #1 was only 5.7.
Too hot today, ambient 95F to work on it and check with #1 injector connected/disconnected vs. starting
thanks
Joe
Supporting Vendor
Joined: Mar 2008
Posts: 1,762
Likes: 14
From: Cumming Ga
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