Throttle Body Problem

[Rob]

Right I have just fitted a new larger 65mm throttle body to my 1.8 Focus and im having a bit of a problem.

The throttle body seems to be "sticking", so when I press the accelerator pedal it either wont budge, or else it hits the floor as I apply more pressure. This only seems to happen though when the engine is running - the pedal moves freely when it is turned off :? Has anyone any idea whats causing this, and what I can do to rectify it?

Its made by Jackson Racing, and resembles the one below.

 

[Gambit]

is there much movement in the engine mounts?

im assuming the throttle body is pretty tight to the bulkhead?

 

[Rob]

Throttle body is a good 6inches from the bulkhead mate, duno about the engine mounts?

 

[Gambit]

hmm maybe not the bulkhead then!

can you not just operate the throttle by hand by gettin under the bonnet? this will show you if its foulin against something

 

[RMS_CLK]

Too hard to say whats causing it. There really should be no difference when the engine is running as this cant affect it. Try removing it and checking its operation over and over, see if you can see anything. It needs to be something major if its stopping your foot from being put down.

 

[Gambit]

if the engine mounts are knackered then there will be movement which can cause it to foul on other things.

which would explain why it works fine when the engine is switched off.

 

[RMS_CLK]

if the engine mounts are knackered then there will be movement which can cause it to foul on other things.

which would explain why it works fine when the engine is switched off.

You need to have a wee word with yourself!

 

[Rob]

Nothing is fouling it and I have used it in my hand and both with the engine on and off and it does work. However the problem arises when the engine is running that the butterfly seems to "stick" making it difficult to control the pedal, its very weird......

 

[Rob]

I have been informed its down to Vacuum that the little ******* is sticking, so Im off to try more instant gasket around the join to see if it helps any....

 

[Jason]

is it well lubricated??

 

[Rob]

Yep we oiled the spring yesterday ..

 

[bob]

Is she still not going 100%? did you try the wee auto ring?

 

[Mr 106]

is the accelerator cable fouling anything? I had mine stick 3/4 open and that turned out to be the cause of it.

 

[Rob]

Nah bob shes banjaxed, throttle keeps sticking and she wont idle below 1200 revs. I slotted in the wee o-ring and it now opens 100% when I give her the boot but thats not cured the other problem :x

Nothing is fouling anything daz, the butterfly isnt jammed open either.

What a pain in the balls this is turning out to be..Ive resealed it and checked my vacuum gauge and its definately not leaking.


Im almost at the point of removing it and going back to standard!

 

[Zetec125]

how about takin it to a decent tuner/mechanic.....

ok so u wanna do it urself but its not workin so bit the bullet-could be something really simple...

 

[Rob]

Had it with a mechanic who spent an hour at it but just did the same things as wot I had been doing and no joy. But he did confirm it is well sealed and there is no vacuum leak...

Ive managed to sort out the idle to 800rpm and get it opening 100% (which it wasnt doing before) but I just cant get this damn stickyness out of the butterfly

 

[Gaz]

Scrob, I heard about a guy with a similar problem who adjusted the stop screw (which limits how far your butterfly can shut) and this seemed to get rid of the problem?

Gaz

 

[Rob]

I have been adjusting the screw like mad Gaz, in 1/8 increments, and no joy.. I was up with your dads mechanic the other day and no real joy with it either.

Bit of a bollocks really - could be hitting Ebay very soon if I cant get it sorted!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!

 

[Fast_CAV]

Butterfly too tight a fit...Grease the edges of the butterfly and try gain... WD40 the linkages aswell

 

[Rob]

Butterfly too tight a fit...Grease the edges of the butterfly and try gain... WD40 the linkages aswell

I dont think this would be the case mate as its only with the engine running - surely this would only apply if it was happening with the engine off?

Im told its the edge of the butterfly biting into the throttle body and the screw just needs more advancing. Grrr pain in the ass this thing, but meant to be worth it....

 

[Cormac]

Who fitted the new throttle body?

Cormac