Ok I have a V6 3.0l V6 with new engine all new sensors. Some timea the truck idles fine at 800RPM but more often then not it will go down to 400 RPM and sometimes die. But heres the kicker if I turn on the AC it will idle fine it brings the idle up. I have taken it to a shop 3 time for this and all 3 time they say they fixed it but low and behold the next day. Any Idea. You advise and ideas will be greatly appreciated. It is also for sale 4999 if anyone is intrested.

 

have you checked the idle control sensor? i'm not even sure if yotas have these, but my ford did the same thing and thats what the problem was. it may be worth looking into

 

vacuum hoses may be hooked up wrong, clogged passages or have a leak.

 

I talked to the mechanic that worked on it last time just now and he said there is a bolt a flat head and to follow the intake hose hose toward the throttle body and I will see it, and turn it to the left little by little. I am at work and the truck is at home so I am not sure what bolt he is talking about.

 

[QUOTE=cmoney79;51051387]I talked to the mechanic that worked on it last time just now and he said there is a bolt a flat head and to follow the intake hose hose toward the throttle body and I will see it, and turn it to the left little by little. QUOTE]


He's talking about the idle adjusting screw; I'm not sure I could find it from that description, but the FSM picture isn't a whole lot better.

So maybe if you turn the idle way up, you'll stop bothering him.

Unfortunately, there are about 100 possible causes of an idle drop. But since the A/C idle-up seems to be working, it sounds like your basic idle speed is set with your throttle plate closed too far. (the good news is that turning the idle speed control up may actually compensate for that.) The throttle plate position at idle is set by a whole bunch of things, including the TPS, the dashpot, VTV, and how tight your cruise control and transmission cables are.

So give setting the idle a try. I would next look at the testing sequence for the TPS; along the way, you'll have to carefully set each of several stop screws, and you may get to the bottom of your problem.