Hey guys I am new to the Form / Thread I bought this truck back in May of 2020 from as a graduation gift It's a 1996 Ford F150 with a 5.0 It has 222000 Miles Has been running great since... But a couple days ago I started having problems with the idle It was running rough at first Maybe 500 rpm on the tachometer And I decided to clean out the idle control valve since I know that's a common issue when cars have idol problem I took off the throttle BodyAnd cleaned it out and took out the idol control about and cleaned out toI put everything back togetherAnd I turned on the truck And now it was idling high at about 1800 RPM Today I decided to go to orileys and go get a new idle air control which was about 50 bucks And I install it back and went to take the truck on a test drive It is it about 1500 rpm I know the truck has a idle set screw So I set that back a couple turns But the rpm is still high at about 1000 rpm Warmed up My old idol was set at about 750-850 rpm But I am not comfortable with the idol set screw all the way back... What should I do next should I check for vacuum leaks or was there a problem with me cleaning the throttle body and there was a sticker that is not to clean throttle body because it has a special coating What should I do next And a truck gave me a Error code It is P1506 which is the idle too high code... what should i do??

 

Look for something binding your accelerator pedal.... Linkage, cable ?... Perhaps the throttle body is sticking and may just need to be cleaned. Look for that coating to be pealing off after you cleaned it.

Hobo

Added: engine coolant temperature (ECT) sensor..... You may need to get this tested.

 

I cleaned the tb yesterday with carb cleaner... alot of gunk came out but the throttle nor the pedal seem to be sticking... and the code went away after i replaced the idle control valve... but that code is now pending on my scanner... you think it might be a vac leak??

 

The idle set screw is not to adjust idle. Idle is controlled by the computer. At least for the 4.9 and I am pretty sure for your truck as well. There is a procedure how to reset and idle screw that has been messed with. I am not enough off a mechanic to explain it but I am sure google is your friend here as well. For your high idle I would check for vacuum leaks first.

Finally, not sure where you graduated from but please use punctuation and paragraphs. It will make it much easier for other people to follow your thoughts and what you are trying to explain.

 

Yeah thats what a figured... I set it back. But oh ok do u have a link or what the article is called by any chance?. And about the vac leak I'm going to do that tmw... its about 635 here in Dallas and it is darker now, but i don't know where to start or what equipment i need... i will be needing help. I might call a older friend tmw that has a '95. Maybe he knows... and for my grammer part I'm sorry haha, i was using text- to- speech everyone, it doesn't do grammer/pronunciation, I was too lazy to type it out haha... but thats for the heads up i didnt realize my paragraph was that bad 😹

 

Sorry for being the grammar police. I'm not a native speaker and make plenty of mistakes myself but some of the resumes I get from college grades are just unbelievably bad. Hence my comment.

Anyway, there are different ways to check for vacuum leaks. From carb cleaner to smoke. I am not a trained mechanic so I'd recommend watching some youtube videos. In the past I have found leaks with a cigar and blowing the smoke into one of the tubes at the vacuum tree on the manifold. Spraying a flamable liquid on a running engine never seemed save to me but plenty of people have done it without issue.

Do you know if the vacuum lines have ever been replaced? Are they hard plastic? I think the original ones are different colors.

 

you could use water in a spray bottle, to find leaks, and start around throttle body, and IAC, you replaced, make sure gaskets(did you use new) didnt get pinched, or move on you when tightened back up, as for running rough, have you done a tune up, plugs, wires, cap & rotor, if you just got it, you dont know how good/bad, or how long they've been in, did you also clean your MAF, they make a cleaner for it and the throttle body, that dont harm them.