Dripper

Wether or not i had a full tank of gas or barely just enough to reach the gas station,either way i def put $5 bucks worth in.Few miles down the road it starts acting up like it doesn't have any gas.Both the fuel pump and filter are good to go.Drove it 1/8 of a mile to my cousins auto shop.I told him what happened and he knew exactly where to look.It was the MAP sensor giving out (he calls it the vacuum sensor).The one he put in was used but worked for 1 1/2 weeks until today.

I started it up today and it stalled.Started it again,no issues until i drove down a cpl streets and it started doing the same thing it did last week.Went home messed with the MAP sensor lil bit,waited and took off again.2 miles down the road i broke down.waited 10 mins and fiddled with it again and drove back home by sheer luck.def sounds as if it has no gas going through.

Is it the MAP sensor or something else giving way? i mean exactly what could it be? The sensor he put in was used but worked.....only for a short time unless it still works but it's another sensor going out, a valve giving away,injectors are clogged or possibly the pump dying on me already? (which i doubt its the pump).....

I'm clueless from this point on,out of ideas

sylver91

Well you shouldn't run your truck on 5$ of gas too often, you'l burn the pump out in no time.

I'd test for fuel pressure on the fuel rail, you should get 45-60 psi.

I would also pull codes to see if its the MAP giving you trouble.

Clean your IAC and check for vaccum leaks too, even around the MAF.

Dripper

i dont normally run on very little gas,only on desperate occasions.The reason i mentioned $5 bucks worth is to give details on that day,at the moment in time for better explanation to what's going on.It was a better way of saying that I knew i had gas in that sucker,no question about it lol.

tomorrow i'll check for pressure on the rail.Which one should i check on the rail? I dont know how to pull codes.Ive came across "codes" here and there on here and word of mouth,but actually doing it? someone would have to show me in person to do that.hands on experience type deal.

I've heard about the IAC but where its at? I dont know.Where's the MAF located? at this point in time after all the work ive put into my truck,I'm become more and more "into it" and further experienced with things,but i dont know everything theres to know.

My stepdad mentioned the spark plugs.It never crossed my mind to check those.Just like an oil change,the plugs may run ever after due date but they eventually need changed.tomm ill check all 6 plugs and go from there and check the spark plug wirings.

If i check the pressure and it's low,would it be coming from there fuel pump or MAP? or MAF? how to tell?

tkx in advance for all the help

MEDF150

Here's how to get the codes. Read the whole web page articles to tell you everything about EFI on our trucks.

http://oldfuelinjection.com/?p=13
http://oldfuelinjection.com

Dripper

Here's what i did.....I hooked a wire on the negative terminal battery and other end on the STI,not the STO.I did this 6x's in a row making sure i counted all pauses and number of diff codes flashing.

STI - 522 522 11 26 126.....

then i checked the fuel pump for codes once and when i did i got this code....

STI - 522 522 1 1 26 542 126 542

522 is vehicle is in neutral,11 is system pass,26 is VAF/MAF out of self test range,542 is fuel pump secondary circuit failure:pcm to ground and 126 is BP or MAP sensor higher or lower than expected.

I'm pretty sure it's the MAP sensor going out cause it did the same thing cpl weeks when it went out on me.putting a used one back in,prob went away until yest.However,I got one bad reading on that fuel pump.

Think maybe the fuel pump is ok and it's just the MAP sensor? or perhaps that BP sensor is bad and the map sensor is good? what's your intake on this? I'll be getting a new MAP today within a few hours unless you think it may be something else other than that.

I haven't cleaned the IAC yet,not sure how,never got that far into it.

The ford book i used for testing has 3 diff set ups combined into one page.i got lost and confused so i chose only one and got all those results up above.

Not to mention that website you gave me def helped out big time! def appreciate it.

Dripper

Advanced auto said BP/MAP sensor are the same thing.We installed a brand new MAP tonight.Drove it for about 4 miles and came back home and it drove just fine,but after rechecking the codes seeing if the MAP was still there.sure enough,the code was still there! VAF/MAF sensor code is still showing,as well as the fuel pump failure code.I'll do my best to find the MAF and clean it.If my truck stalls again as if it has no gas,i'm gona highly guess the pump is giving out already.

Plus,the code 26 popped up stating "VAF/MAF out of self test range" is that a good or bad thing?

Dripper

I still have another problem.The first time it starts up for the day,it stalls on me,but any time i start it up there after,it runs fine.It always stalls on me when i start it up for the first time on a daily basis.Been doing this for a few days.I think the pump is going out.whats your thoughts? anyone?

I'm still having issues locating the IAC sensor and MAF sensor.I know in a round-about-kinda-way where they're at,but precisely I don't. (called autozone.They stated my truck was NOT equipped with a MAF,which is prob why i cant find it)

I made a short vid clip of my engine.check it out.if anyone can spot either IAC or MAF sensor...let me know

(I'm having issues uploading my short vid.I can only have up to 117kb.My vid is 12,000kb but its only 1 min long.Can someone out there help me on this.)

sylver91

The MAP is on the passenger side near the firewall under the hood.

The IAC is on the throttle body.

edit: 92 MAF will be on the intake near the air box, I was reading it wrong lol

f150cam

the MAF should be right next to the air box on the air intake going to the throttle body.

but does his truck have MAF or MAP? it cant have both lol.

sylver91

Whoops I trying to say MAP sensor

I read it wrong