Zone BB Throttle Body Troubles

[wilkos]

Hi all, Iv fitted a BB Throttle body to my Sport which I got off the zone and fitted it to the car no problems, the engines been rebuilt and everything was running ok.Anyways the car had been back on the road a few weeks and the idle speed was getting gradually lower and lower to the point it would cut out at junctions..so I decided to adjust the idle speed with the screw but as soon as i turned it snapped off
I had a couple of other small jobs to do so i took the throttle body off again and ordered a new screw from the dealer.
I fitted the throttle body back on the car today and I'm experiencing more problems......The idles great now but when you rev the engine it hunts and wont rev... its good up to about 1500 rpm then it dies and its as if nothing is there when your foots to the floor.. it also backfired.Is there something else wrong? have a got a faulty throttle body? or have I just missed something ?
Any suggestions because I'm tearing my hair out lol ......cheers

[FlappySocks]

Shouldn't have turned the screw - the butterfly valve should close completely.

[Templ8e30]

Did you fit a new TB gasket ?

Could be a bad air leak.

Cheers,

Iain T

[Andy335Touring]

Did you adjust the TPS so it clicks as soon as the throttle moves from the closed position ?

[HartgeH27]

You need Ant !!!!!

[d6dph]

We all need an Ant in our toolboxes!

[wilkos]

Did you adjust the TPS so it clicks as soon as the throttle moves from the closed position ?

sounds a daft but how do you adjust?? I replaced all gaskets so no trouble with air leaks

[Andy335Touring]

The TPS(number 2) has slotted mounting holes that allow it to be adjusted, you need to hear it click as soon as the throttle moves from it's stop/closed position.

[wilkos]

Ok so once iv heard it click then i can set the idle speed is that right??
thanks again.

[SPADGE]

Hearing it click is one way of instaling a tps but using a meter would be far more accurate.

[Jackle]

Shouldn't have turned the screw - the butterfly valve should close completely.

No it shouldn't, there should be a slight gap between the butterfly and the sides when in the closed position. Not too much, obviously, but enough to let a bit of daylight through when you look at it (off the car of course!).

Also, the idle is controlled by the ECU and the ICV, you cannot change the idle speed setting without reprogramming the ECU. All the screw does is adjust the amount of air the throttle butterfly lets through when closed, the ICV will compensate for any (within reason) changes you make.

Have you tried taking off the ICV, making sure the internals move freely, and giving it a good squirt of carb cleaner?

[ric325i]

as jackle wrote you should check the idle control valve 1st but could be an air problem also?

it could be a simple ICV problem? hope its jamed or clogged? then its an easy fix

[Quaser]

could be a faulty afm