guys i realy realy dont know what the heck is going on.. Fuel (or something problem)

[F 150Cobra]

question?

why is it when in D or R and idling at 500 the volt meter slowly decreases.. then immedetly when i start running again it goes back to normal.. but does this only when the headlights are on.. any ideas? maybe dirty IAC ?

 

[jbish28]

Mr fixit is one the right track. Remember the basics here. The Kiss rule (keep it simple stupid). Any engine needs the basics, air fuel spark and compression. Whenever I run into a deal where I am told to replace the pcm I go back through my tests and make sure that is the correct conclusion. Then I call tech line and see what they have. You do not have that luxury. So go through what information you have again before jumping to conclusions. Do not ever throw parts at your truck to fix a problem, you will end up broke.

 

[jr32560]

I have done it and seen it many times-people over analyze things-i agree with jbish28 -KISS-has always worked for me and a lot less money-may take more time but it saves money and a box full of used still good parts laying around