First of all I know, that there s penty of threds on this topic.

My challenge is, living in Denmark makes it difficult to get spare sparts and almost impossible to get a proffesionel mecanic to look into the problem

My F-150 5,4 l. from 1998 yesterday started running rough when idle. My first oberservation was 1000-1100 rpm when stopping at red lights. It was 5 min. from my home, and in those 5 minutes I experienced variations in idle from 1100 rpm. down to 500 rpm. but without getting the engine to a complete stop. At the same time the "check engine" light in the dashboard turned on

I messed a litte with the engine today after reading threds about Vacum leaks and the iac valve. And today I Also experienced to engine comming to a complete stop after running500-600rpm in neutral for about 10 seconds.

I localised the AIC and knocked carefully on it with a hammer. It had an effect on the rpm for a very short while. But still the engine runs rough.

Taken this effect into consideration, can I be sure that the problem is due to the aic-valve.

If not so, I have read about a vacum leak. What is it, and how do I find it.

Could it by any chance have something to do with the AC. I have noticed that it on, no matter in what position a place the bottom for the ventilationsystem execp the off position. The AC blows lots of could air.

When parking the car I have noticed water comming in drops from a little left of the middle of the car just behind the frontwheels. I keeps dripping for at least one hour, but i am pretty sure that it is plain water hopefuly from the AC.

I hope that some one "Over there" can give me a clue on how to solve my problem.

If spare parts are needed, it is pretty important to me, that it is the right parts, as shipping from US to Denmark can take up to 4 weeks.

If any one should take the effort and answer this thread, please do not use abreviations. The English language is hard enough for me. Tecnical english will probably be more or less impossible for me to understand.

A long story. Thanks for your time.



My

 

could be iac not moving fast enough, and when you tapped it with a hammer it may have broke it free. i'd pull it off and see how dirty it is. that and clean the maf, and the throttle body. then again the iac is like 47 bucks at autozone so you could just change it. to check for a vacuum leak you could just hook a vacuum gauge onto it and it should read between 17 and 22"hg.

 

Hell, I cleaned my IAC once... I was in traffic and the engine went down to about 500 RPMs and ran like junk. I took IAC off, sprayed it with brake cleaner, air dried it off, slapped it back on.... ran mint

 

Thanks, I will try cleaning the IAC this weekend. What is the MAF and where is it located. And you`r right Matt, 47 bucks is no great deal, but again, living in Denmark and ordering in the US make it a bit more complicated.

 

You need to find a OBD-2 scanner and read out your diagnostic codes. If the CEL came on, you will have one or more stored codes. These will help greatly with the diagnosis.

MAF = mass airflow sensor. It's in the intake tube between the air filter and the throttle body. Clean it with spray electronics cleaner if you can't find MAF cleaner.

 

Problem solved

The hose leading to the iac was completly destroyed. A new hose, and it running greater than ever.