Outer Limits 4x4 Board

Hi i have a 89 GQ tb42 on gas and petrol the car runs fine on gas but will not idle on petrol. It drives fine on petrol when the throttle is open does anyone have a clue on what is wrong?

At the back of your carbie, there is this cold start style choke. it looks like a pin that comes out of the bottom and it applies pressure onto the accelerator lever. Mine sticks every now and again, and wont idle. just wants to stall even when backing of. it may need adjusting at the screw (dont turn it too much, otherwise it will rev high), but start of by giving it a spray with silicone spray or WD40 to loosen it up.