X-F250 182 Posted April 4, 2016 Hey guys, got an issue with the carb 4.1 in my ute. Changed belts and fluids and went to get everything up to temperature so I did a few laps of his back paddock. At some point it threw the alternator belt and got a bit warm so I let it sit for a few hours after I changed the belt. Ever since then it starts and immediately goes up to 2000rpm. Tried adjusting the idle screw, doesn't do anything. Any idea what it could be? The throttle cable is brand new and isn't stretched. Sent from my GT-I9305 using Tapatalk Share this post Link to post Share on other sites
Kiwi-E 731 Posted April 4, 2016 Hows it going mate I had a similar problem however the fast idle was probably only around 1200 ish revs It turned out that inside the chock housing on the side of the carb, that the stop for the fast idle cam had broken off which was allowing it to rotate further than it was meant to and getting jammed in the fastest idle position. Its a terrible photo but it shows the fast idle cam rotated right around anticlockwise until it jammed. The broken off stop And to fix it just bang in some filler of some kind I'm not sure if this is your problem as the fast idle screw would have to be wound in a fair way for it to idle at 2000 revs but it might be worth looking at. Otherwise check that you have some slack in your accelerator cable and that the tranny kick-down cable isn't stopping it. Also i believe some AC fitted cars have a solenoid on the carb to raise the idle when the AC is on but you'd have to ask someone else about that. Shouldn't be too hard to sort out once you find the problem Share this post Link to post Share on other sites
bear351c 10,273 Posted April 4, 2016 Throttle return spring, Sticky needle/seat. Dizzy slipped ? Share this post Link to post Share on other sites