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Sticky Throttle Body?

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Sticky Throttle Body?
« on: April 06, 2009, 08:26:19 PM »
Just got a brand new used 1990 Samurai (fuel-injected). The gas peddle has alot of "stiction" when at the first point of engagement. I know it's not the throttle cable because when when I manually move the throttle linkage cam, it sticks. Once it's past the point of departure, it moves freely - no stickyness. So, when I'm parked at a light I get alot of stiction when I first start going, then when I start shifting and such, moving back and forth on the throttle, there's much less stiction when I have it at 0 throttle for the brief second of changing gears.

Fuel injector dirty? Need to clean/rebuild/replace throttle body or fuel injector?


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Offline jtgh

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Re: Sticky Throttle Body?
« Reply #1 on: April 06, 2009, 10:19:09 PM »
not cable
so
first off that dash pot must retract , after 30 seconds of starting.
if not  you cold start vsv is messed up.
hot start it retracts immediately

no that leave 2 more things
the TPS is buggered in side
or the bottom of the Butterfly plate is mucked up. (PCV sludge)

you can look down inside with flash light and open the throttle and look to see if there is muck below fly plate.

that is about it.

http://carfix.stufftoread.com/fresh-air/fresh-air.html

see fly plate. in FIGURE 2?

if you remove TPS , it must be re calibrated.  (mark it first.)
must be calibrated to with in 8 thou.

« Last Edit: April 06, 2009, 10:29:18 PM by jtgh »

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Offline jtgh

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Re: Sticky Throttle Body?
« Reply #2 on: April 06, 2009, 10:30:30 PM »
my in 91 kick and there very much the same.
small evolution.

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Offline TopHeavy96

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Re: Sticky Throttle Body?
« Reply #3 on: April 07, 2009, 08:29:56 AM »
Get a can of throttle body/carb cleaner, and a small brush. Scrub the heck out of the throttle plate and body, You're probably feeling the plate pop loose from the inside if the body.
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Re: Sticky Throttle Body?
« Reply #4 on: April 07, 2009, 07:17:53 PM »
Some more info:

- If I push that device with the rubber boot (dashpot?) all the way in, it sticks a bit.

Here's a picture of the air intake hole. The butterfly is at the bottom and does not appear to be gummed up, but this is the first time I've ever looked at this sort of thing. When I turn the throttle linkage cam, the butterfly opens (as does if I push on the dashpot).

From here, do I just spray carb cleaner or throttle body cleaner down this hole?


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Offline idaholwb

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Re: Sticky Throttle Body?
« Reply #5 on: April 07, 2009, 10:37:18 PM »
Use throttle body cleaner, similar to carb cleaner but won't hurt it... The nut on the side of the cable guide that attaches it to the throttle shaft... loosen it like 1/8th of a turn. In other words, just barely. I've run across it before when people tighten it for some reason and makes the throttle shaft stick because it's too tight. Try that before anything else and let us know how that works...
97 Sport
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Re: Sticky Throttle Body?
« Reply #6 on: April 09, 2009, 06:10:24 PM »
Ok,

- I have done what was suggested: used about 1/4 can of throttle body cleaner to clean it. Twice. No change.
- tried adjusting the throttle linkage cam nut (11mm). No change.

- After a great deal of tinkering and trying to figure out what does what, I am almost positive that the butterfly valve is getting stuck on the intake throat, possibly because it's being allow to rotate too far, it's off-center, or something. It doesn't appear to my untrained eye to be off-center, so I can only assume it's just rotating too far and getting stuck on the wall of the intake throat.
« Last Edit: April 09, 2009, 06:23:54 PM by One Sick Puppy »

Re: Sticky Throttle Body?
« Reply #7 on: April 09, 2009, 09:59:29 PM »
As I got more educated about exactly what parts were what, I was able to do better Google searches and came up with a variety of other people who were having the similar problems, but on different vehicles. Apparently there's what is called a "throttle stop Screw" and almost every mention of this item is an admonishment NOT TO MESS WITH IT. I'm pretty sure that is what I've circled in the image below. Most of their problems were fixed by carb cleaner, but there was a couple that mentioned some binding such as I was experiencing. I had adjusted this screw earlier today and didn't find it helpful, but the engine was off and so I found that with the engine on the linkage cam would sit against that screw since the rubber boot thingy would retract. Anyhoo, long story short... I'm idling at around 950-1000rpm vs. about 850-900, but the problem is gone. Things might need to be tuned up better, but this is probably a good fix for now. Thanks for all the help!