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Topic: Throttle stuck??? scary (Read 2251 times) previous topic - next topic

Throttle stuck??? scary

Reply #15 –
UPDATE:
i took it to the mechanic today and they couldnt figure it out, but they recommended me to a mechanic right down the road that works on this type of car a lot. wouldnt you know it, it happened again on my way there. i managed to get it there with it still happening and i walked in and he looked at it right away.

the first thing he checked was the throttle cable, and that was fine, it wasnt sticking. next he looked at this circular thing with a vacuum line on it, and he determined that was the problem. he told me that is used to adjust the throttle when you have accessories on to keep the engine running, like the ac.

he told me to keep the ac off until my appointment. when i got home i tested his theory of it being the ac.

sure enough, when i turn on the ac and hit the throttle it goes all the way up to 2000 and it wont go back down. as soon as i turn off the ac, hit the throttle it is back to 800 rpms.
i am not sure what the part is called, i didnt ask him, but i can describe it
it is circular piece of metal, that looks like you cut an egg in half, meaning it is somewhat pointy on one and and flat on the other.
it has a vacuum line going to it, and there is this black bar that comes in and goes out. when the ac is on, the piece comes out, which pushes on the throttle

 
here is the weirdest part, when the ac is on, the little bar pushes the throttle out, but if i manually push the little bar back in, the throttle doesnt come back with it. when i turn off the ac, and it isnt pushing the throttle forward, as soon as i push the throttle bar, it goes all the way back and the rpms are fine

first question, can anyone tell me what this part is called. i can take pictures if the details above arent good.

second question, do you think that part is causing the issue? does it make sense that the ac would cause the issue. i rarely drive with the ac since i get headaches with car ac (all cars, not just the t-bird)

one thing i wanted to add, if i disconnect the vacuum line and hit the throttle it is fine

Throttle stuck??? scary

Reply #16 –
Description  escapes me. 

Quote
next he looked at this circular thing with a vacuum line on it

If you can post a picture I can most likely tell you what it is? 
-- Or -- at least were is it located (be specific)

Throttle stuck??? scary

Reply #17 –
here you go brother, i took 3 pics. the really close one is the part, the one somewhat further away is to show the rough location and the furthest picture is to show the location at a distance. (this is the drivers side)


Throttle stuck??? scary

Reply #18 –
Remember I said...

Quote from: TurboCoupe50;224799
Sounds more like the TPS or idle motor has a problem...
The newer ones actually had a little motor inside them(are larger), yours operates from vacspooge... Possibly can be adjusted, that's what the small hex is for on the threaded bolt below it... Could also use the bolt head on the other end...

Throttle stuck??? scary

Reply #19 –
Quote from: TurboCoupe50;225624
Remember I said...

 The newer ones actually had a little motor inside them(are larger), yours operates from vacspooge... Possibly can be adjusted, that's what the small hex is for on the threaded bolt below it... Could also use the bolt head on the other end...



good call. is this part hard to find

Throttle stuck??? scary

Reply #20 –
The vacuum to it is controlled by the throttle kicker solenoid. The 84 EVTM says the solenoid is on the front side of the driver's side shock tower.

Throttle stuck??? scary

Reply #22 –
Ford calls your part the Throttle Positioner Assembly.

As TurboCoupe50 pointed out, some CFI's (Throttle bodies) use a
small DC motor called and Idle Speed Control Motor) in place of the
vacuum type. 

Which came First and why Ford changed is unknown but best guess is the 1984-1987 models were transition period before full EFI.

During these years Ford also played with their heads, trying to mill them as thin a possible.  I know in 1984 Ford used a number of different production heads each different -- my guess- trying to find a balance between weight,  saving material, and no head warpage.
This was before MLS (multi-layer-steel gaskets) were used.

Throttle stuck??? scary

Reply #23 –
i just got back from the shop, they said the problem is the egr valve and a solenoid for the egr.

he is trying to locate the parts now