I need help i own a 1999 F-250SD 5.4 5speed and i have replaced the aic valve and vaccume lines and other things, but my truck still doesnt like to start after it has sat for a while weather its hot or cold it doesnt like to start. when it starts it has a low idle arround 500 RPM and wont kick up till after like 15min or so. Could this be my Mass air flow sensor? Oh yeah and i have crappy fuel milage too.

 

It may be dirty. You can try spraying the filiments with brake parts cleaner to see if that helps. Just don't touch them. A bad MAF will usually throw a code. You may also have a bad injector that is leaking into the engine causing the plug to foul untill it cleans itself off after running for awhile.

 

Don't guess, pull the codes so you don't waste money changing parts at random.

 

yes u can use brake/parts cleaner on it but it's got to be non chlorinated kind

 

I always use the AutoZone brand. It leaves no residue.

 

I've read you can't/shouldn't use brake cleaner on the MAF.... Can anyone explain or confirm???? Thanks.

 

You don't want to use carb cleaner because it leaves a residue when it dries. Either use brake parts cleaner or electrical contact cleaner.
I've never had a problem with brake parts cleaner.

 

I rarely use carb cleaner for anything, lol. Brake cleaner is like duct tape.... 1000's of uses.

Ok, I usually stock up on the $2 brake cleaner from walmart or the dollar store. I have about 10 cans of AutoGuard Non-Chlorinated Brake Parts Cleaner. Its essentially Acetone 67-64-1, Methanol 67-56-1, Tolulene 108-88-3, and Carbon Dioxide 124-38-9. (All those numbers makes it look fancy!) Is this ok to use??? Thanks Man!

 

Ok, I cleaned it with the brake cleaner and gently hit it with compressed air. I guess it worked. It really didn't look dirty to start with.

 

Just for future reference, CRC makes a product specificaly for this task. I know that oreilly's carries it.

 

How about using MAF cleaner on it. That's what I use.

 

Update. CEL came on a number of days ago. I finally made it to autozone for a diagnosis. Of course, 1443 came up,,,, again. And this time bank 1 and 2 O2 sensors as well. So, all the autozone guys agreed that anytime you have bank 1 and 2 at the same time it means the MAF sensor is bad or dirty. Well, I just cleaned it per instructions on this thread! Are you sure brake cleaner will not hurt MAF sensors?

 

CRC makes a cleaner specifically made for that job. You don't want to leave any residue on the sensor. Same problem like over oiling some air filters.

 

I did buy a can of MAF cleaner while I was at autozone that cost the price of 3.5 cans of brake cleaner..... and it was ON SALE, lol.

But I had already used the brake cleaner I described above. Kinda funny I that it makes trouble now after I cleaned it. I'm in the dark because I don't know what it is, what makes it fail, what can damage it, etc....

 

It sounds like a bad MAF. With the engine cold, start and confirm that the problem still exists. Then shut the engine off and disconnect the MAF. If the engine seems to run better right away with the MAF unplugged, there is a good chance that it is the culprit. This doesn't always work, and is just kind of an old trick. NEVER UNPLUG A SENSOR WITH THE IGNITION ON.

Have you done a fuel pressure test, or a vacuum test? Other than the evap code you stated, were the O2 codes lean or rich?