High Idle
Jun 14, 2021 | 07:31 AM
#1
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High Idle
Hi guys,
Took my 91 pickup 22re for a camping trip a couple weeks ago. On the way back I noticed it was idling high (about 1200 rpm) when warmed up.
Now it idles at 1000 - 1200 rpm when being used. However, if I start the truck warm, it will idle at about 800 rpm and once I drive somewhere it will return to 1000 - 1200 rpm.
I adjusted the idle screw. It will lower the rpm when I start the truck warm. But it doesn't affect the idle rpms after I've been driving.
The engine runs relatively smooth otherwise.
I recently did the exhaust and put a new o2 sensor in. The new sensor has a loud whine so I'm thinking to put the old one back in (it didn't have any problems). Could this be the cause?
I also recently adjusted the valves. I had to loosen all of the valves as they were much tighter than 0.008 and 0.012.
Any suggstions are appreciated.
Thanks!
Took my 91 pickup 22re for a camping trip a couple weeks ago. On the way back I noticed it was idling high (about 1200 rpm) when warmed up.
Now it idles at 1000 - 1200 rpm when being used. However, if I start the truck warm, it will idle at about 800 rpm and once I drive somewhere it will return to 1000 - 1200 rpm.
I adjusted the idle screw. It will lower the rpm when I start the truck warm. But it doesn't affect the idle rpms after I've been driving.
The engine runs relatively smooth otherwise.
I recently did the exhaust and put a new o2 sensor in. The new sensor has a loud whine so I'm thinking to put the old one back in (it didn't have any problems). Could this be the cause?
I also recently adjusted the valves. I had to loosen all of the valves as they were much tighter than 0.008 and 0.012.
Any suggstions are appreciated.
Thanks!
Jun 14, 2021 | 12:19 PM
#3
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Joined: Jul 2005
Posts: 2,345
Likes: 656
From: Chiloquin, OR
Yes, definitely. The TB gets a lot f nastiness built up in it, especially from the EGR system.
It might help to clean out the idle adjust screw's air passages. Turn it down to the bottom, counting very carefully. Then you take the screw out completely and clean the passages with a little shot of carb cleaner. Check the o-ring on it while you have it out. They get brittle, and easily damaged. The o-ring on the idle adjust screw is readily available everywhere, and very inexpensive. A thin layer of Vaseline on the o-ring helps preserve it, and makes a better seal.
It cleans the passages where the vacuum lines plug in, too. A little shot of cleaner, bada-boom! All nice and cleaned out.
Check out the IACV, too. Make sure it's closing properly when the truck is warmed up. The FSM has the check out procedure in it.
Good luck, and let us know how things work out!
Pat☺
It might help to clean out the idle adjust screw's air passages. Turn it down to the bottom, counting very carefully. Then you take the screw out completely and clean the passages with a little shot of carb cleaner. Check the o-ring on it while you have it out. They get brittle, and easily damaged. The o-ring on the idle adjust screw is readily available everywhere, and very inexpensive. A thin layer of Vaseline on the o-ring helps preserve it, and makes a better seal.
It cleans the passages where the vacuum lines plug in, too. A little shot of cleaner, bada-boom! All nice and cleaned out.
Check out the IACV, too. Make sure it's closing properly when the truck is warmed up. The FSM has the check out procedure in it.
Good luck, and let us know how things work out!
Pat☺
Jun 14, 2021 | 02:54 PM
#4
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Joined: Sep 2007
Posts: 8,380
Likes: 871
From: San Francisco East Bay
All good advice, but start with the easy stuff. When it's warmed up and idling high, pop the hood and push on where the throttle cable connects, in the "close" direction. Does the idle drop down? You may have something sticking in the throttle cable, Transmission cable, cruise control, ...
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