Throttle Body
Thread Starter
|
New User
Joined: Nov 2002
Posts: 16
Likes: 0
Throttle Body
I have a 98 Ranger with a 3.0 engine and the throttle body is sticking. I have cleaned it several times to include taking it off of the engine to get to the back side. It stll seems to stick at around 1300 RPMs at idle. I can turn it by hand and the idle will drop to 900 rps at idle. Is there any way to take the unit apart to further clean it or should I just replace it?
Post Fiend
Joined: Jul 2005
Posts: 8,462
Likes: 4
From: Durant, OK (SOSU)
Sounds more like the IAC. A high idle can be a vacuum leak, but since when turning it by hand the idle drops, I suspect the IAC (idle air control valve).
It's the metallic cylinder on the side of the throttle body, you can remove it (two bolts, careful with the gasket) and clean it with throttle body cleaner, spray liberally until the dripping stuff is clear, then let air dry before replacing.
It's more of a band-aid, the problem will come back eventually, I remove and clean mine at every oil change while the oil is draining. Simple enough.
It's the metallic cylinder on the side of the throttle body, you can remove it (two bolts, careful with the gasket) and clean it with throttle body cleaner, spray liberally until the dripping stuff is clear, then let air dry before replacing.
It's more of a band-aid, the problem will come back eventually, I remove and clean mine at every oil change while the oil is draining. Simple enough.
Postmaster
Joined: Jan 2003
Posts: 4,417
Likes: 3
From: Durham, NC
If you can manually close the throttle body, and the idle drops back to 900 RPMs, then the problem IS NOT the IAC, OR A VACUUM LEAK!!!! It could be simply a weak return spring on the throttle body. Make sure your throttle cable is free and not binding.
Last edited by Bob Ayers; Jan 29, 2007 at 09:48 AM.
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
It's really very clear from your problem description, you don't have an IAC solenoid issue. Along with what Bob correctly noted, you should inspect the throttle linkage leading to the gas pedal (including pedal pivot) followed by a thorough inspection of the TB itself, in particular the operation of the butterfly when the cables are disconnected. Feel for binding, excess/unusual play (radially and longitudinally), etc etc.
More Turbo
Joined: Dec 2006
Posts: 624
Likes: 2
From: FL
Originally Posted by Russ8393
I have a 98 Ranger with a 3.0 engine and the throttle body is sticking. I have cleaned it several times to include taking it off of the engine to get to the back side. It stll seems to stick at around 1300 RPMs at idle. I can turn it by hand and the idle will drop to 900 rps at idle. Is there any way to take the unit apart to further clean it or should I just replace it?
if you want to... take it off again and hold the TB up to the sunlight and see if any light bleeds through edges of the butterfly. then you will know if it's closing all the way or not...
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
Originally Posted by 97ranger xlt
you should check for binding cable but...
if you want to... take it off again and hold the TB up to the sunlight and see if any light bleeds through edges of the butterfly. then you will know if it's closing all the way or not...
if you want to... take it off again and hold the TB up to the sunlight and see if any light bleeds through edges of the butterfly. then you will know if it's closing all the way or not...
More Turbo
Joined: Dec 2006
Posts: 624
Likes: 2
From: FL
Originally Posted by CowboyBilly9Mile
Ummmm, there had better be some light showing through there; this is because there is an adjustment on the TB providing for default idle in the event that the ECM and/or it's components don't provide for proper idle control. No light showing = no default idle = someone tampered with it and it needs to be restored (easy to fix).
another easy test is to unplug the IAC .. what should happen is the engine will default to limp mode idle (ie lower idle). if this doesn't happen there is a vac leak somewhere.
also....before i forget (my new mantra for high idle) check the PCV valve!
Last edited by 97ranger xlt; Jan 29, 2007 at 07:10 PM.
Trending Topics
Post Fiend
Joined: Jul 2005
Posts: 8,462
Likes: 4
From: Durant, OK (SOSU)
Well...since ya'll are obviously so sure, let's give it a try.
Unplug the IAC and see what happens (do it with the vehicle warmed up...or it may die).
Unplug the IAC and see what happens (do it with the vehicle warmed up...or it may die).
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Post Fiend
Joined: Feb 2003
Posts: 6,940
Likes: 2
From: Eastern WA
Originally Posted by 97ranger xlt
another easy test is to unplug the IAC .. what should happen is the engine will default to limp mode idle (ie lower idle). if this doesn't happen there is a vac leak somewhere.
More Turbo
Joined: Dec 2006
Posts: 624
Likes: 2
From: FL
well all i can go on is recent experience. the computer threw a code pointing to the IAC. it was a false code. the computer was fooled to think the IAC was bad due to a vac leak caused by a bad PCV valve which will in itself not throw a code. so in the end disconnecting the IAC would not make the idle default to around 750 rpms like it should because the vac leak was still present. the IAC was good and tested good electrically.
what i'm trying to say all was not as it appeared to be....
i'm not opposed (far from it) to tried and proven ways of testing for vac leaks. i don't think that's old fashioned at all , lol!
i think the OP should go ahead and see if the IAC is good and test for vac leaks especially the PCV.
sometimes, as we've seen, people tend to replace parts that don't need replacing and then will never know the real cause of the problem.
one guy recently replaced the whole manifold, the TB,TPS & the IAC when the high idle problem could have been solved with a simple $3.50 pcv valve...
ahh for the good old days when the idle was set by us not some stupid computer...
what i'm trying to say all was not as it appeared to be....
i'm not opposed (far from it) to tried and proven ways of testing for vac leaks. i don't think that's old fashioned at all , lol!
i think the OP should go ahead and see if the IAC is good and test for vac leaks especially the PCV.
sometimes, as we've seen, people tend to replace parts that don't need replacing and then will never know the real cause of the problem.
one guy recently replaced the whole manifold, the TB,TPS & the IAC when the high idle problem could have been solved with a simple $3.50 pcv valve...
ahh for the good old days when the idle was set by us not some stupid computer...
Last edited by 97ranger xlt; Jan 29, 2007 at 09:08 PM.
Thread
Thread Starter
Forum
Replies
Last Post
btswank
1987 - 1996 F150 & Larger F-Series Trucks
6
Nov 1, 2009 09:44 AM
danm
1980 - 1986 Bullnose F100, F150 & Larger F-Series Trucks
2
Feb 19, 2000 10:13 PM