1990 Toyota 4x4 Idleing problem
03-02-2009, 12:25 PM
#1
Registered User
Thread Starter
Join Date: Apr 2007
Location: McMinnville, Oregon
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
1990 Toyota 4x4 Idleing problem
I know that this has been covered a million times but im stumped. Just recently purchased a 1990 toyota 4x4 w/3.0 v6 and manual transmition.
I have owned it now for 2 weeks, I finaly had a chance to go wheeling with some friends, however when we returned the idle started to act wierd. Before it ran great, now it wont idle below 1300 rpm and when i apply the brakes the idle surges between 1400 and 1000. I have already tried burping the cooling system, the idle screw is turned all the way in, checked oil preasure, checked and rechecked all vacumme lines. any help would be appreciated
I have owned it now for 2 weeks, I finaly had a chance to go wheeling with some friends, however when we returned the idle started to act wierd. Before it ran great, now it wont idle below 1300 rpm and when i apply the brakes the idle surges between 1400 and 1000. I have already tried burping the cooling system, the idle screw is turned all the way in, checked oil preasure, checked and rechecked all vacumme lines. any help would be appreciated
03-02-2009, 12:47 PM
#3
Registered User
Thread Starter
Join Date: Apr 2007
Location: McMinnville, Oregon
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
No water in engine, I did check the brake booster vacumme line it is fine, how do you test a brake booster? And i forgot to mention that sometimes when shifting the rpms shoot up yo around 3500
Last edited by rbissonette; 03-02-2009 at 12:50 PM.
03-02-2009, 12:58 PM
#4
Registered User
Join Date: Sep 2008
Location: middle of no where Alaska
Posts: 4,355
Likes: 0
Received 2 Likes
on
2 Posts
I'm kind of getting this info from a Chilton's repair manual.
To test for vacuum leaks:
1.operate the engine at idle for at least one minute without touching the brake pedal.
2.turn the engine off and wait one minute.
3.lightly pump the brakes several times. each time should produce less pedal travel, if vacuum is present. If no vacuum is present, ie a leak, then it will pump without much resistance.
To test for system operation:
1.Run it at idle for a few minutes. Turn it off.
2. lightly pump the brakes until all the vacuum is gone, ie, its difficult to pump the brakes.
3.start the engine, and operate it at idle. If the system is working correctly, the pedal should "fall" to the floor if constant pressure it applied to the pedal.
something like that...
To test for vacuum leaks:
1.operate the engine at idle for at least one minute without touching the brake pedal.
2.turn the engine off and wait one minute.
3.lightly pump the brakes several times. each time should produce less pedal travel, if vacuum is present. If no vacuum is present, ie a leak, then it will pump without much resistance.
To test for system operation:
1.Run it at idle for a few minutes. Turn it off.
2. lightly pump the brakes until all the vacuum is gone, ie, its difficult to pump the brakes.
3.start the engine, and operate it at idle. If the system is working correctly, the pedal should "fall" to the floor if constant pressure it applied to the pedal.
something like that...
Trending Topics
03-02-2009, 05:21 PM
#8
Registered User
I just cleaned my throttle body and my truck is doing the same thing.
Idles a little high after the cleaning (I was expecting that), but I wasn't expecting the idle to drop and surge when I press on the brake pettle.
I'll have to check my vacuum ports.
Idles a little high after the cleaning (I was expecting that), but I wasn't expecting the idle to drop and surge when I press on the brake pettle.
I'll have to check my vacuum ports.
03-02-2009, 06:47 PM
#11
Registered User
Thread Starter
Join Date: Apr 2007
Location: McMinnville, Oregon
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
Cant get the base idle below 1300 before this happend i when it was running good i had checked the timing and it was on the money. Got idle screw all the way in and still 1300 rpm
03-02-2009, 07:14 PM
#12
Registered User
Join Date: Dec 2007
Location: Rochester, Washington
Posts: 500
Likes: 0
Received 0 Likes
on
0 Posts
check out this page on testing and cleaning the throttle body
http://www.ncttora.com/fsm/1993/engine/93throttle.pdf
03-02-2009, 07:54 PM
#13
Registered User
Join Date: Mar 2005
Location: Encinitas, CA
Posts: 261
Likes: 0
Received 0 Likes
on
0 Posts
Test your TPS out with a meter, it is really easy. I can walk you through it if you need. I just changed mine and it was an amazing improvement. If it is a vacuum problem, you will most likely feel it when accelerating, it feels like the engine stalling out or like there is a strong head wind.
03-02-2009, 11:26 PM
#16
Contributing Member
Test your TPS out with a meter, it is really easy. I can walk you through it if you need. I just changed mine and it was an amazing improvement. If it is a vacuum problem, you will most likely feel it when accelerating, it feels like the engine stalling out or like there is a strong head wind.
03-03-2009, 09:20 AM
#17
Registered User
Thread Starter
Join Date: Apr 2007
Location: McMinnville, Oregon
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
I just got done checking compression it is as follows #1 184, #2 180, #3 182, #4 180, #5 186, #6 175
I will try to get the intake cleaned out today sometime
I will try to get the intake cleaned out today sometime
03-03-2009, 01:45 PM
#18
Registered User
Thread Starter
Join Date: Apr 2007
Location: McMinnville, Oregon
Posts: 16
Likes: 0
Received 0 Likes
on
0 Posts
03-03-2009, 01:47 PM
#19
Registered User
Join Date: Mar 2008
Location: Temecula Valley, CA
Posts: 12,723
Likes: 0
Received 4 Likes
on
4 Posts
you don't adjust the IAC (well, at least shouldn't- it was adjusted when it was installed on the throttle body).
For the most part, it either works or doesn't. You can, however, clean it.
For the most part, it either works or doesn't. You can, however, clean it.
