[Jgladman]

Gday, ive just put a 4k toyota carby on my sierra, new choke works, the accelerator cable seems to be fine, but when I turn the car on it just starts reving really high going nuts. Is there something I have missed? It didnt do it on the stock carby. Cheers

[fordem]

Is the 4K Toyota carb a double barrel downdraft? Are both throttle plates closed when they should be? Is the idle speed screw set correctly?

[Jgladman]

fordem wrote:

Is the 4K Toyota carb a double barrel downdraft? Are both throttle plates closed when they should be? Is the idle speed screw set correctly?

Yea no idea to all haha

[fordem]

With all due respect, if you can't answer any of those questions, you're in over your head and need to find someone with some amount of experience to assist.

[bumstein]

Correct.. but for a start perhaps post some pics of your carby and setup and maybe we can help for starters? No guarantees!!

For starters make sure your start it up with the throttle cable and choke disconnected. It’s simple to hook the cables up just a little tight and not realise. I’ve done it before

[HarryHoudini]

bumstein wrote:

For starters make sure your start it up with the throttle cable and choke disconnected. It’s simple to hook the cables up just a little tight and not realise. I’ve done it before

Good advice,start there and work back.

[Bammo]

you need a good stiff return spring to properly tension the factory throttle cable pivot point onto the 4K carby. I bought a collection of them from Bunnings and tried different weight springs till I got a good balance of return to idle vs too much weight needed on the accelerator. From memory the return spring just looped around the throttle cable end and hooked into one of the nearby hose clamps on the airfilter. About a $3 fix...