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Throttle Cable Spring Not Working?; Round 2: Ice in TPS?
Topic Started: Nov 22 2011, 12:09 AM (1,677 Views)
Jittney
Anchorage 92 XFi

Disclaimer: Not my metro
Neighbor lady's 2000 3/5 ~ 150,000 miles (give or take)
2 days ago, it would not start for her.
Sons and I push started (battery worn down by now) and when it started, it went straight to WOT.
She turned it off.
Push started again.....same thing....straight to WOT.
She borrowed a car to go to work.
Checked the gas pedal, it works, but the throttle cable is sticking out 2 inches....so it's not retracting.
Popped the hood....and checked the spring.
It was not retracting the throttle cable.
Manually pushed it back.
Did it a few times....back and forth....sprayed it with Brak Clean....and all was good.
She used it for a day...back and forth to work....and all was good.
She wanted to park it in another spot today.....and no start.
Wore the battery down trying.
Meanwhile I came home from work.
Would not push start this time.
Even with 3 motivated teenage boys and me pushing....windchill is well below zero.
Park it.
Check the cable....disconnect the cable....disconnect Spring #12 in this picture.
Cable moves freely in the housing.
Spring #12 retracts to small size.
Throttle Cable Spring setup does not snap back.
I can manually push it back and forth, and 'occasionally' (ie when you don't want it to move) it will move on its own.
Tried loosening up the nut and spring washer on the end, in case that was too tight....no change.
Butterfly valve insideTB is not all the way closed, but I don't see or hear anything grinding in there.
Looking again at the Throttle Cable Spring setup, I notice that it is not snapping back (even when persuaded) to the 'stopper' that it should strike against.
Check my 94....and see that, yes, it should strike the adjustable stopper.
Go inside to check the TB from the 93.
Yes, it the Throttle Cable Spring setup smartly snaps back into place to the adjustable stopper when I turn it clockwise and let it go.
Hmmmmm
Take off the TPS of the 93 setup and observe the whole movement.
Put it back on...with a little preset twist before fastening down the 2 screws...and 'viola', I can get the 93 spring setup to not hit the stopper.
However, even though it does not hit the adjustable stopper, it still snaps back normally.
The 2000 simply does not spring back as it should, but it doesn't look like it's 'broken'.
My 93 and 94 spring setup does not match the 2000, so it's not a swap if it's 'broken'. Rats.
Frankly, it's too cold to go back out anymore for me tonight.
Brak Clean can wouldn't spray tonight...so I tried De-icer, and then WD40 and then PB Silicone...and then heated it up with a little butane lighter....no, it didn't blow up :)
Nothing worked to free up the movement.
But, if there was ice in/on the spring, I wanted it gone.
Think I got that covered.
Camera on my cell phone froze up taking one picture.
Yeah, it's cold.
Tried calling iceman, but he's working on up the Slope. (probably colder up there)
So, what do you think?
Has anyone seen this before?

Edited by Jittney, Nov 22 2011, 09:21 PM.
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allmountain40
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Never had that happen, but if the cable moves freely, and the spring is not broken, there are two things you can check. Since the TPS is directly attached to the butterfly shaft, if it is binding, it could cause the throttle to not spring back. To test, mark position of TPS very carefully, and remove. If throttle functions normally, you have found your problem. Second option is the bushings on butterfly shaft are wore out. :thumb
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Old Man


:hmm 30 years ago I spent a winter working the N Dak oil fields. We had 'summer' pumps and 'winter' pumps. changed out every year. The winter pumps had more clearance in the working parts because they would get so cold that they would not move.

You keep mentioning how "cold" it is. With my above experience it makes me wonder if there is something in that setup that needs just a little more clearance....... :hmm :hmm
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Jittney
Anchorage 92 XFi

Thanks, allmountain40.
Agreed....makes sense to take off the TPS and see what might be binding in there.
I didn't want to get into the TPS, unless there's no other logical option.
The phrase semi-frozen comes to mind when describing the throttle cable spring motion.
The thought that ice has build up someplace still seems tangible.



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Jittney
Anchorage 92 XFi

Old Man
Nov 22 2011, 02:24 AM
The winter pumps had more clearance in the working parts because they would get so cold that they would not move.

Interesting that the winter pumps had more clearance.
I would have thought that the contracting metal would have precipitated lower clearances.
Thanks for your input. Old Man....I'd really like to be able to resolve this economically for her.
It's been hitting below zero for a few days.....with windchills going even farther down.
It's expected that metals get stressed with heat/cold fluxuations.
Other things have gone 'bellyup' in the last week, but this one has eluded me so far. :)
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Jittney
Anchorage 92 XFi

Round 2:
Came home....checked to make sure the spring was still sluggish....yup.
Put a hair dryer on low....pointed it at the TPS.....waited 5 minutes.....tested the spring.
Moving almost normally.
Still not hitting the adjustable throttle stop.
Started up the car....it went straight to WOT.
Hopped out of the car and pushed it back to lower idle.
It kept creeping up.
Push down....creep up....repeat 10 times.
Never hit the adjustable throttle stop, though.
Pull up on the gas pedal....idle drops....think it was hitting the throttle stop.
Hmmmm.
Adjusted the cable....it's now hitting the adjustable throttle stop.
Owner hopped in the car...revved it up....spring snaps back correctly.
She's low on fuel.
Advised her to go to O'Reilly's and get some sort of HEET, and fill it up with 87 fuel.
And....get a can of carb cleaner.
It would seem that there is ice in the TPS.
No, I have not taken it off....yet.
Any thoughts on drying out the TPS without opening it up? :hmm
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crankcase


Heat gun?

If you try it, just don't leave the tip pointed at one spot for more than a few seconds; move it around
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Bad Bent
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Facetious Educated Donkey

Jittney
Nov 22 2011, 09:28 PM
Any thoughts on drying out the TPS without opening it up? :hmm
No, but if you do open it up mark it first then remove it. The book says to install it rotated to the left (CCW) and then rotate it clockwise to the original marks. That's so the prong is to the left of the TB shaft that moves the TPS prong. :-/

Pull up on the gas pedal....idle drops....think it was hitting the throttle stop.
Hmmmm.
I concur, it could still be the cable.

How does part #5 look?

Posted Image
Jittney's Diagrams chapter 3 line 5 ;)
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Jittney
Anchorage 92 XFi

Part 5 looked good.
When this first happened, there was a spare small round piece of black rubber on the floor by the gas pedal. Not sure where it came from. Think maybe it was a guide or rubber stopper. I couldn't find it in the parts diagram. Not sure what happened to it or what it did. Sheesh. That's pretty lame.
At any rate, the cable was maybe an eight of an inch out of adjustment.
She's back from doing her Thanksgiving shopping....and I've not heard of any new problems.
So far, it's been a cheap fix. :thumb


Jump ahead a week.
Neighbor lady's son came over to say the car wouldn't start again.
Weather was down in the single digits to below zero.
Carb cleaner on the spring side....no help.
Heater on the TPS....and the spring loosened up and started snapping back.
Got the car started.....went to WOT....reheated the TPS.....things settled down.
4 days later....and no more problems.
Weather is not quite so cold, but still below freezing.
I'd still call the problem 'intermittent' and I'd still say it appears to be something frozen in the TPS.
I have not taken it off yet....as the 'heat it up' method is still working.

Edit: jump ahead several months...
I replaced the ISC.
The butterfly valve was still staying open a bit after replacing the ISC.
I took the TPS off.......the butterfly valve closed....and then put the TPS back on.
Finally it's staying closed.
There was oil in the air cleaner cover, so I replaced the PCV valve.
I thought it was good to go, but the idle was low and it still cranked a bit long on start up.
A week later....
Replaced the spark plugs, cap and rotor.
And now...
The idle is cutting out....so next is hose replacement and see about setting the idle and timing.
Seems like everything shows up in cold weather :smackface
Edited by Jittney, Dec 23 2012, 03:13 PM.
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