rubenz Posted June 2, 2011 Report Share Posted June 2, 2011 Ok guys i had posted a while ago that my truck was having some idling issues so i finally decided to try and figure out why. Well i have narrowed it down the automatic choke. It seems as though the choke stays on and will not turn off by just goosing the throttle like normal. It stays on all the time and makes the truck idle at 2000rpms. Now if i disengaged the automatic choke by hand the truck will idle just fine at around 1000rpms. now i am trying to find out if this is a standard easy fix issue with the 720 or if it is complicated (carb rebuild/ replace) or if i can somehow disengage the auto choke permanently. what do you guys suggest? truck is an 82 4x4 Quote Link to comment
SoCaLKiDz Posted June 2, 2011 Report Share Posted June 2, 2011 Im pretty sure mine was doing the same thing. What i was told to do is look at the plug from the carb to the wire harness. I had to cut those wires and make my own connection. It seemed to work pretty well. Try it and let me know if it helped ~Dillon Quote Link to comment
datzenmike Posted June 2, 2011 Report Share Posted June 2, 2011 It's an external linkage adjustment. More likely the linkage is just dirty and sticking. When the choke is off the fast idle linkage is free to drop down under it's own weight and release the fast idle cam. This is the fast idle cam with set screw . When the choke is on a linkage lifts up and rotates the cam and the throttle closes on a higher step giving a fast idle. Get a can of carb spray and liberally spray this area. Hold the throttle partly open and open and close the choke plate. The cam should be free to rotate. . Quote Link to comment
rubenz Posted June 2, 2011 Author Report Share Posted June 2, 2011 yeah i checked everything for binding issues but it all moves fine. i lubed everything up and it made no difference. I think it is the autochoke...it's the part that is like a little butterfly valve within the carb. it has its own seperate linkage. also another issue is that the idle is unable to be adjusted (most likely becauase of this problem). I also added in some seafoam to help clean out the carb itself to see if that helps any. it's just weird because it was working fine (although the idle was high) and then suddenly it just started acting up and revving to 2k. the truck is driveable but it sure kills the gas mileage!! Quote Link to comment
datzenmike Posted June 3, 2011 Report Share Posted June 3, 2011 Sort of misread the OP. When warmed up look at the choke plate. It should be full open ... not like this: (or partly open) The choke heater is electric and gets it's supply from the auto choke relay. The auto choke relay powers the choke heater only when the motor is running and the alternator is charging. So if checking for power the motor must be running. You could make a small jumper wire and supply the choke heater directly from the battery. If working the choke plate should open fully in about 5-8 min. . Quote Link to comment
rubenz Posted June 3, 2011 Author Report Share Posted June 3, 2011 Yes That is exactly the problem. The choke plate stays fully closed the entire time. So I need to figure out why the auto choke relay is malfunctioning Quote Link to comment
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