Idle problem

[C.Fuller305]

I have a 1994 ford ranger 4.0 v6 4x4. For some reason my truck will sometimes idle at 2200, 1000, or 650 rpm there is nothing that is done different that will cause the weird idle. I have replaced the fuel and air filter, Injectors, cpu, Idle air control valve, Throttle position sensor, and I adjusted everything so that it would idle at 650 rpm. I made sure everything was tight and torqued down but my idle wont stay consistent. I have had a shop rewire my mass airflow sensor and I checked the voltage and ohms going from the cpu to the mass air flow, and found no problem. My 02 sensors have been replaced and are operating properly. I really need to get this fixed because it is eating up my gas and with these prices stuffs not cheap. Any suggestions will be tried

 

[Garth Libre]

You didn't mention the throttle plate and where it intersects with the throttle body. I have not had this problem with modern cars but I have seen it often with older carburator cars where the throttle plate has worn out the holes in the carb where it pivots. As a result the plate gets hung up and causes intermittent sticking. My problem with modern throttle bodies is that you are not supposed to pivot the plate unless it is electronically disconnected as it throws the computer off. I don't fully understand modern throttle bodies but I have seen and heard of worn pivots which caused this exact problem you are describing with your car.

 

[C.Fuller305]

You didn't mention the throttle plate and where it intersects with the throttle body. I have not had this problem with modern cars but I have seen it often with older carburator cars where the throttle plate has worn out the holes in the carb where it pivots. As a result the plate gets hung up and causes intermittent sticking. My problem with modern throttle bodies is that you are not supposed to pivot the plate unless it is electronically disconnected as it throws the computer off. I don't fully understand modern throttle bodies but I have seen and heard of worn pivots which caused this exact problem you are describing with your car.

I have not thought of that ill check it tomorrow and see if thats the problem