MAF low voltage

[NoLimit95]

When I pull codes on my car, it's showing that the MAF is getting low voltage readings. I have swapped the entire MAF box with a completely different CLEAN MAF and I still get this code.

Question is, does the MAF have any kind of relay that would cause this to happen after the car warms up? The cold start is perfect, just put brand new 764's in last night, changed TPS, changed the little box that feeds the EGR valve, I have new (8mm) wires, a new Motorcraft alternator, new 1000 CA battery.

What happens is, when I crank the car, it idles very good and smooth. I can get out on the road and drive and it seems to have full power but after the temp gauge reaches almost the 1/2 way mark, it still runs good until I let off the gas and coast up to a red light or stop sign or to make a turn. That's when it does it the most. The car just starts stalling and acts like it's going to shut down and it has shut down a couple of times and the CE light is coming on now more since I changed the plugs from Motorcraft platinums to copper 764's and the code I'm getting is (157) "Mass Air Flow Sensor - Signal Voltage Is Too Low"

Tommy, the code I was showing before were double digits but now I know that mine reads triple digits and (157) is the code I get. This only happens after it has warmed up and I have unplugged the MAF while the car was setting in the garage in idle and it would stall out and sound the same as if it would while I drive and let off the gas. After I make a turn, it's jumping sometimes like it's starving for gas but the fuel filter is new and the fuel pump has been changed so it's neither of those. After some hesitation, it will pick up and get going until I let off the gas again for the next turn.

Could my third cat be stopped up? When I get back in the garage and shut it down, the exhaust is making all kinds of popping sounds like it is extremely hot and the flow coming out of the tail pipe doesn't seem to be what it should. I am running on a muffler delete also on stock exhaust for now. We thought it was a fowled plug because after I would gas it, it would start the stalling and bogging like it had fuel in the cylinder that needed to be burned away. The MAF code I'm getting is really confusing me and if there is a relay under the hood for this, I have a 93 setting out back full of relays.

Keep in mind, this happens only after it has warmed up so whatever it is, it's only acting up after it gets hot and acts the worse when I let of the gas and coasting. I even done a power brake in the garage and when I let off, it done it again. BTW, I'm loving this transmission but this stalling is ruining everything for me and I need to get it fixed. I have a brand new crank shaft position sensor setting here in the box but if it don't need it, I ain't changing it. Any help would be very much appreciated. Please, if you don't know, don't guess because I have done all the guessing that can be done. Right now, I just want to get rid of the low voltage reading the MAF is showing. If the CE light comes on 2 times, I get the code read out to me 2 times. (157)

 

[XLRVIII]

"sounds" like either the maf is unpluggged, which I'm sure it isnt.. or you have a broken wire in the maf harness..

Doubtful the crank sensor is a contributing factor.

and..remember what I said about eec 4 codes.

The code you get may or may not be the actual issue, sometimes the code you get is a product of another issue that a code isn't set for.
It's stupid.. I know..but it IS eec 4.

Wish I could be of more help, but you seem to always post the "you've stumped the panel" questions...lol

You "say" it cant be the fuel pump, but didn't you say that before..and then you went back inside..and found somethng wrong? (cracked hose?) I cant remember..

this is the part of the story where we start grabbing straws.

Your getting a MAF code
you changed the maf and the code still exists....

if you cat was plugged it wouldn't matter if it was warm or code..plugged is plugged.

Since this began after a plug change, I'd go backwards thru all that..because you had to remove the intake tube..so you might have "jacked a wire" in the maf harness (my straw grab for today)

 

[driller]

Have you tried reading the MAF voltage at the computer?

 

[NoLimit95]

This sounds like it's getting so much closer. The fuel pump issue... and when I say this, it's going to sound crazy but it seriously did happen this way. I had a slight leak on the top of my fuel tank and it was coming from the thin rubber gasket. Before I decided to change it, I wanted to run the car as low on gas as I could and I "thought" that I did because when I pulled into the garage, it started stalling on me. Get that??? lol, this is when the stalling issue really got started and I thought it was running out of gas but it really wasn't.

I changed gaskets and I went ahead and took the pump that came out of the 93 because it looked and appeared to be newer and I knew that nothing was wrong with it. I installed the pump and gasket and fixed my leaking issue. Got in the car and cranked it up and it was not out of gas. When I dropped it, it had at least 2 gallons in the tank, so..... obviously, my stalling was just starting on me when I had pulled it into the garage for the last time before the pump and gasket swap but I didn't know this.

Ok, mow on to the MAF sensor. Yes, the wire is plugged up but, I have the best idle and the best running car that I could ask for when it's cold and then when the right amount of heat finally gets to it, the stalling begins and only after I let of the gas and coasting to a stop and especially after a WOT, 1st to 2nd gear change and let off the gas. It's real bad then. Just coasting to make a turn, it stalls and sounds like it's about to go dead but it doesn't and then it will jerk a few times and almost wanna shut off and then it gets going again and will smooth out until I let off the gas again.

Yes, I do agree that the MAF code could be coming from another reason. Maybe the idle gets so low and the car almost dies while the sensor is powered that it causes it to throw the code, I'm not sure. Now on a side note. I did change out the drivers side coil pack or done a swap with a known good one from the 93 and no change. The other night, I had the car running in the garage and loosened each wire one at a time on the coil pack to check for spark and all 8 wires were giving off good spark but.... the #8 wire did give off spark and when I plugged it back in, the idle jumped back to normal again. That very plug that I took out, didn't look fowled from the outside but the little pin above the resistor was crooked and only came over the top, covering about 1/2 of the resistor and all the others were fully covered and none crooked.

Now I have someone saying to swap out the other coil pack. I can do this because it's setting right there in the garage on the other engine and it's an easy quick swap. He also heard it and was there when I tried the spark and wire test on each boot of the coils. Friend of mine seen when I pulled the #8 plug wire enough to see a spark and then plug it back in and the idle went to normal without anymore stall. I rode him in it and he had the feeling that it might be a fowled plug and this was before the coil test. His thoughts were either there was a fowled plug or that coil needed to be swapped out. So now I'm down to looking for a broken or loose wire on the MAF and changing out the passenger side coil pack. I do not trust these flashing code lights either because it's not helping pinpoint the issue.

All I know is that since I changed the plugs last night, the CE light is coming on like it's disco now. Stalling worse and more hesitant when pressing the gas during a stall. Oh yeah, did I mention that I love this transmission?

This is almost like someone giving a kid a new X-Box 360 or Playstation and "the best game out" but the TV it's being played on keeps cutting off and on just enough to keep you from enjoying the game. Make sense?

This is why I asked if there was a relay for the MAF. I thought maybe it could be getting hot and acting up. What you said about the cats makes me happy. At cold start, it runs like a million dollars and the first 5 to 10 min of driving is top notch and then you let off the gas and then it's on!! It's really annoying the living :q:q:q:q out of me because it's something that I can't find. If I could find it, I would fix it or have it fixed.

I'll check the wire real good and if possible, I will get the wire off the 93 outside and swap them out and I'm going to swap the coils out and give that a try too. I will post the good or the bad update.

 

[NoLimit95]

Have you tried reading the MAF voltage at the computer?

Have not done this and wouldn't know where to start with that.

 

[NoLimit95]

Swapped coils out with known good ones and it is still doing the same thing. Sometimes I can unplug the MAF while it is running and the idle does not change but if I shut the car off and then crank it back up, I can unplug the MAF and it acts like it wants to die until I plug it back in.

 

[XLRVIII]

man this is starting to sound like a goofy injector hanging open..

especially the part about it acting stupid right after wot.

maybe a bad injector or injector harness?

you could swap them over, hell.. before long you will have swapped the 94 engine with the 93..one part at a time

 

[NoLimit95]

man this is starting to sound like a goofy injector hanging open..

especially the part about it acting stupid right after wot.

maybe a bad injector or injector harness?

you could swap them over, hell.. before long you will have swapped the 94 engine with the 93..one part at a time

It seems like I have taken mine apart and swapped everything over. This is making me crazy. A fuel injector has crossed my mind. I would have to change all 8 of them because I don't know which one would be bad. Remember, this only happens when it gets warmed up. After the coil swap, I backed out of the driveway and had O/D off. I stomped it down and both tires were roasting up the hill and then it hit 2nd gear and the ass end jumped over (just like I like it) and then I let off the gas and it sounded like it was about to die out. I turned around to come back and it sputtered a little and then it was ready again but as I cam down the hill, it bogged a little and I pulled back into the garage.

 

[XLRVIII]

I would have to change all 8 of them because I don't know which one would be bad. Remember, this only happens when it gets warmed up..

yes swap all 8..

and remember an injector is an electromagnetic solenoid, subject to heat issues along w/ most all electronics.

wouldnt take long to swap em out.

another heat affected electronic part...VCRM which does contain high speed fuel pump relay AND injector drivers

 

[XLRVIII]

another thing... disturbing spark plug wires usually created a missfire for me.

the first plug change or two (50K miles) they were fine.
but on the third or 4th plug change it seemed the core of the wires had gotten brittle and would break.

MSD wires I replaced every other plug change or before the 1 year warranty expired.
Ford Racing wires I never had that problem with.
the stock motorcrafts after 100K would go :q:q:q:q up if you messed with them very much

 

[XLRVIII]

you cant say :q:q:q:q?
T1TS???

WTF?

 

[NoLimit95]

Ok, when you say not long, how long "round about" figure because I have never changed an injector before but I'll go right out here now and do all 8 of them. I have the garage at about 74 degrees so it's not a problem to go do this.

Any special tool that I might need for this? I have just about everything needed but like I said, never changed one before. Have a feeling I will learn something new tonight.

 

[XLRVIII]

i can call you a douchebag, but I cannot tell you that your plug wires have gone T!TS up.

LVCEEEEEEEEEEEEEEEEEEEEEEEEEEEEEEE

 

[NoLimit95]

another thing... disturbing spark plug wires usually created a missfire for me.

the first plug change or two (50K miles) they were fine.
but on the third or 4th plug change it seemed the core of the wires had gotten brittle and would break.

MSD wires I replaced every other plug change or before the 1 year warranty expired.
Ford Racing wires I never had that problem with.
the stock motorcrafts after 100K would go :q:q:q:q up if you messed with them very much

The plug wires are less than a year old and only on their 2nd plug change as of the other night. Last plug change was when the wires were also changed. All plugs were gapped at .054 and the 764's I just put in the other night are also gapped at .054

 

[XLRVIII]

relieve fuel pressure at the scrader
remove the feul rail hold down bolts..do not drop any into the bolt eating chasm first gen intake.

:q:q:q:q its a 30 minute job tops..

practice removing them from the 93 motor..lol
that'll tell you if youve gotten in over your head

 

[NoLimit95]

Thanks Tommy, I got work to go do. If this works and you have PayPal, you will be paid just for putting in your 2 t i t s cents.

Letchya know what happens by morning.

 

[XLRVIII]

The plug wires are less than a year old and only on their 2nd plug change as of the other night. Last plug change was when the wires were also changed. All plugs were gapped at .054 and the 764's I just put in the other night are also gapped at .054

im jus sayin..

you right on the verge of that window..the timeframe and miles i mentioned above are not set in stone..

 

[XLRVIII]

if the injector harness is on the 93, swap it as well..
might as well kill two birds with one stone
G'nite and G'luck bro

 

[NoLimit95]

if the injector harness is on the 93, swap it as well..
might as well kill two birds with one stone
G'nite and G'luck bro

Tommy, the whole damn car blew up and don't ask me how because I have no idea. I only changed 4 injectors on the drivers side and put everything back together just as it came out and bolted it all back just as it was.

Cranked it up and it died. Cranked it again and it died. I thought maybe it needed to build some pressure in the rail so I kept trying and then finally it started. It was a rough idle but I still thought it needed to build pressure. I ran it up to 1500 to 2000 rpm's but I could tell that something still wasn't right. I decided to just turn it off and shut the garage door back. When I pressed the door button inside the car, it got down about 1/2 way and then I reached to turn the car off but before I could, the whole front end exploded into a ball of flames and fire came inside with me.

I'm ok, just got cut and burned a little but lived through it and don't know how. All I can say is that the car is now history. I don't see how this could be rebuilt and I have an entire front end for it but it's seriously not worth it. I'll get pics of it tomorrow.

 

[kustomizingkid]

Wow... fuel must have leaked somewhere... that really sucks...

 

[NoLimit95]

Wow... fuel must have leaked somewhere... that really sucks...

Yeah, some came out but it was only a few drops from the rail where each injector goes in. I almost started it with the hood up and checked but I didn't. I thought all was good but apparently not. Fuggit, I'm just glad I made it out alive. People have already been here and don't know how I made it and neither do I. I was being looked upon, big time!

 

[XLRVIII]

HolyF*CK...you're kidding me..

I dont know what to say bro...dammit.

 

[XLRVIII]

Go back and see if the fuel rail hasn't lifted..
Sounds like it wasn't secure and blew off the top of the injector.

either way, it's a moot point...glad your still among the living bro.
Sorry bout the car, Yes someone was looking out for you, and I think that same person is trying to tell you to "give up" on that car...sorry to say

 

[Aquabrit]

I bought myself an extinguisher for such a situation... Think I'm gonna go and buy me another pretty soon!

Well Terry, you've taught me something that I wasn't even considering - when my car is back together, I'm gonna push it outside before I first start it!

 

[NoLimit95]

Go back and see if the fuel rail hasn't lifted..
Sounds like it wasn't secure and blew off the top of the injector.

either way, it's a moot point...glad your still among the living bro.
Sorry bout the car, Yes someone was looking out for you, and I think that same person is trying to tell you to "give up" on that car...sorry to say

lol Tommy, I think after that, everything lifted. I promise it was more than secure. I checked it three times and made sure all plugs were plugged. As for giving up on it, I have no choice now. I'm about to go get pics of it. The investigator just left from his picture taking so now I'll go get mine. Might be a little while though because my right leg is F'd up.


Martin, I had one and I emptied it on the car and under it. No match for that fire and yes, do put it outside before starting because this was SUDDEN!