TB butterfly ticking....

[iCupra]

Hi all,

ive been having a read about and have recently cleaned my TB as it was only ticking over at 500rpm, its now fine BUT........

after running the car, if i stop the engine but keep the key in the on position with all electrics on i can hear the TB ticking, i took the inlet pipe off and you can see the butterfly twitching (which is the ticking), it was doing this before i gave it a clean and i just wondered if it was normal?

any advice on this would be much appreciated,


P.S - forgot to mention its a 1999 2.0 8v cupra with no mods

 

[suj]

could be the butterfly open sensor thing (sorry dunno actual name)
you know on the TB there is a switch covering the butterfly pivot, that might have nackered,
or you the "TB position sensor" where the TB's cable attaches might have been nackered mate

 

[iCupra]

im not sure i know what you mean mate

 

[suj]

have a look at your TB mate, you will see a plastic type controller (with a lead going into it) there should be 2 of these plastic controllers on the actual TB

1 controls how much the butterfly is open (can remove by allen key IIRC) this is basically directly above the pivot point of the butterfly (like you are looking at the top of the butterfly), so if this has gone, it can cause the "twitchiness"

the other is where the accelerator cable attaches onto the TB (you know the black plastic thing you can pull to rev engine from the actual engine bay) well if you look near that, there is another controller that knows the distance this black plastic pulley has moved (so tell the controller above how much to open/close) so you know when your car is cold, the ECU controls the revs

hope this helps

 

[iCupra]

excellent! cheers mate, i will have a look in the morning.

i must admit, a lot of the smaller unprotected cables felt quite stiff and brittle so it wouldn't surprise me if there is a break!

thanks again.

 

[suj]

no problem mate

as my position sensor broke totally off the metal plate it was bolted on, was shocking

my moneys on 2 things
1) TB butterfly sensor
2) just a clogged up TB

for the latter, just buy some carb cleaner from motor factors/halfords, and have car running, have someone sit in the car, take off intake pipe, and spray away, you will see a black cloud from all the crap that was stuck, but then your sorted

 

[iCupra]

did #2 today, i cleaned the TB today as it was stalling when cold and even when i got it warmed up, it would only idle at 500rpm, a quick clean inside with some carb cleaner (without even taking it off) and it runs like a dream! much smoother and ticks over at 900/1000rpm.