Please Help, ee90 carb questions.

[AE86fan]

Ok, so I have gotten rid of the crap carb on my ee80 (the one with the sliding valve thing on the top) and upgraded to a twin choke downdraft carb off the newer model car (ee90).

I got the whole manifold and carb from pick-a-part bolted it on and bugger me it started first pop and ran sweet.

The problem is, I think it is running with the choke on all the time as its idleing real high.

I have tried to find the idle adjustment screw but doesnt matter what I turn the idle wont come down. Yes I have checked for vacuum leaks and Im pretty sure there are none.

The new carb has what looks like a electric motor hanging off the choke flap at the top of the carb, do I somehow need to put some voltage into this motor to turn the choke off and bring the idle down??

I have tried putting +12V into it but nothing happened.

Any help would be greatly recieved as this is my daily car that gets driven all the time and its a pain in the arse driving every where with the engine screaming its ring off. I really want to solve this myself as the car isnt worth what a machanic will charge me to fix it......

[rollaholic]

is the choke flap open or closed? from what i remember from my 2E the choke is controlled by coolant temp, and i have been told that those particular carbs do give trouble with the choke as a common fault.

thats just hearsay though!

[Crucible]

Check the fast idle cam adjustment,

open and close the throttle and see where it stops/rests against if you're unsure. There should be and adjustment screw that sits in the cam grooves, should be a matter of adjusting it to get rpm req when cold.

the other screw which isnt making a diff will be base idle. That wont make any differance when cold because the fast idle cam will be stopping the throttle. You can adj base idle once its up to temp.

[AE86fan]

Which one is the fast idle cam adjuster, is it the big screw with the spring on on the back left of the carb if you are looking down from the top? I have adjusted the one I thought it would be but when I turn it, it makes no difference to the position of the throttle stop.

[Crucible]

Which one is the fast idle cam adjuster, is it the big screw with the spring on on the back left of the carb if you are looking down from the top?

have a look to see where the throttle is stopping against, I couldnt say off the top of my head.

it looks like a half moon with stagged steps, the fast idle screw will be attached to the throttle and will be resting against the steps. As it warms up the cam twists and the idle drops.

btw, make sure the cable has slack aswell, if its tight it wont return to idle...

[AE86fan]

Thanks mate, I know which one you mean I will go and have another try at it. I have a feeling that I going to have to sort something out as far as the electric motor thing. Im guessing the newer carb has an electric choke setup that the old carb didnt.

[Crucible]

thats all good mate, yeah just wire it to 12v ign on supply, i usually wire it to coil Pos. yep you're right, those crappy stock 2e SU carbs are coolant operated.

wheather the choke be coolant or bimetal (electric) operated it should be mechanically linked to the fast Idle cam. So in short, the cam must twist for the idle to drop.

no twist = no idle