Starts then stops - Help

[piper]

My 2002 Explorer gave me grief today for the first time since I've owned it and I'm stumped.

It starts and idles for about 3 seconds then shuts off. I've check fuel pressure and its a consistant 65-70psig at the fuel rail. If I press the gas peddle when it is about to quit, it will rev up with no significant loss in fuel pressure.

I other other words, I've rule out it being a fuel problem...what else could I check? There is no check engine light codes. Would a bad MAP or MAF cause this?

Thanks for your help.

Piper

 

[410Fortune]

65-70 psi? wow this may be accurate for yuor truck but the first gens are at about 32#

is 70# correct for the later model returnless style fuel systems?

First off what engine do you have? 4.0L SOHC or 4.6L V8?

 

[piper]

60-70psig is correct for the 2002. I have a V8 (4.6l). I've made some progress in diagnosing this problem. If I unplug the MAF, the truck idles fine, as soon as I plug it back in, the truck quits.

Should I just replace the MAF or could there still be other problems?

Piper

 

[Turdle]

I would try cleaning the maf

do you use a reusable type air filter by chance?

 

[piper]

Yep, one month ago, I put in a K&N cold air intake system. How do I clean the MAF, looks very sensitive, it also looks very clean???

Is there a way I can test it...Haynes gives me no proceedure.

Are K&N style filters known for damaging the MAF?

Piper

 

[Turdle]

I have read on this forum of the filter oil causing contamination of the element in the sampling tube of the maf
This is what you want to clean, you should be able to find the procedure if you search for it

good luck, and let us know what you find out

 

[410Fortune]

excessive oil from teh K&N filter can get on the MAF sensor wires and then dirt sticks to it, etc.
the sensor wires are very delicate, basically how it works is power is sent through them and as the air passes over them it cools them off, thus giving the computer a reading of how much air is flowing.
When you clean them you dont touch them you spray them with MAS cleaner or electrical contact cleaner and let dry.

Also when you install a free flow filter or complete cold air intake it is necessary to reset the computer, clear allcodes so it is ready to learn and adjust for the increased air flow.

Cleaning the MAS is simple, it is also covered on this forum in detail frequently.
YTou can try a search for the proceedure.

Do not I repeat do not go buy a new MAS, I clean mine once a year or so as part of preventive maintenence.

 

[piper]

OK, let's consider this the most successful post for me ever on the internet!!! You guys rock. I just got in from cleaning the MAF (I used brake clean, it's all I had), I then blew it dry with some gentle compressed air.

I installed everything back together, turned the key, and it purred like a kitten, settling down into a smooth idle.....PROBLEM SOLVED.

Thank you very very much for your help, now how often should I be cleaning this thing? Consider it took 1 month from my K&N install to act up, I say it'll need cleaned every three weeks or so.

Piper

 

[410Fortune]

oh my brake cleaner is awful harsh, but it sounds like it did the trick, nice work!

once a year should do it.
I am guessing all the oil thats gonna come off that filter already has, the key is to NOT over oil the filter after cleaning