I have a 1997 f150 4.2 L when I run it on the highway FOR A LONG TIME WHEN I COME TO A STOP IT IDLES RUFF AND WANTS TO SHUTOFF IF I PUT IT IN NEUTRAL it stays running but is still ruff . sometimes the engine light comes on will driving I had it check out and it comes up fuel mixer I had it to the shop 2 times they say they can't find anything I have talk to 2other people 1 said its the fuel pump. usely a fuel pump works are it dosen't .the other said it the mass air flo sensor.can anyone help

 

Could be a dirty fuel filter change that out reset your computer and see if that helps.

 

http://www.englishchick.com/grammar/

 

Rould re ra rot r rings.

A rood race ro rart rould re rith ra routine raintenance items rike ra air rilter, rark rugs and rires.

Rit rounds ro re rike ra rair ror ruel row robrem.

Ronridering rat rit's ra '97, rit ray reed ra rot ra rings.

I rolved ry "ruff running" robrem ry reaning ra EGR rysrem rand ra IAC (Idle Air Control Valve)

You rould raro rean re MAF renror.

 

lol DogBoy...

Jack did you happen to run over a dog maybe? Sorry, couldnt resist. I dont eggzactly hav the bset speling iether.

Try a fuel filter first, then get a fuel pressure test done if it doesnt help. Could be, but shouldnt be the MAF. That should have its own code.

Let us know how it turns out.

 

thanks for the responses I tried the fuel filter it diden't work I put in new air filter and pvc valve and it is still running ruff .

 

JP

last i checked didn't wasnt spelled diden't.......did you even go to that grammar website that was given to you?? lol


OK Jack Palmer...welcome to the boards...

5.4

 

Could somebody elaborate a little more on what a "rough idle" means. I think I may have a rough idle problem too. When my 4.6 is at operating temperature and I stop the car and put the transmission into park, the idle seems to vary as much as 300 rpms.

Sometimes when I turn the engine on (doesnt matter if the engine is warm or cold) it will stumble for a few seconds and almost stall. Every 1 out of about 100 starts the engine will stall as soon as I put it into gear. Other than this I have no problems. Should I take it into my dealer or not worry about it?

 

this has almost caused several crashes for me
i have the same problem with my truck and several other guys on here as well ford says there is no problem there but everone else says other wise there is someone on here who has a list to add your name to but i don't remember right now my engine was replaced and i still have this problem and it not the IAC.

because there are so many people that have this problem
i belive that there should be a class action lawsuit to have it fix.

 

My engine was idling rough also, same symptoms as described above. I did everything to fix it. I checked the mass air flow sensor (by pulling out the conector and starting to see if it still ran), replaced the fuel filter, replaced the PVC Valve, and everything in between, so I finally submitted and took to FORD so they could read off the codes from the OBDII system. Turns out my truck's Idle Air Control Valve (IAC) was getting a low voltage. I went to O'Reilly Auto Parts and bought a new one for $44.00 (instead of $75 from the dealer). Installed in 2 minutes (easiest thing ever done), and it was like new. The rough idling was gone and my truck never run better. So, thats how I fixed my delema. Ask about those code readoffs from ford. Sometimes, they might not see a potential problem and not inform you about something. Hope that may help. I've heard FORD say that they get a lot of IAC Valve's "sticking".