MAF Sensor 95 Explorer At my wits end!

[Randymann]

Hey, I have read many posts on here and this is my first post. Thanks in advance for reading!
I have a 95 Explorer XLT 4.0 auto trans. and am at my wits end trying to figure this out.

My truck was running like a Swiss watch. I got some fuel, drove a mile or two and it started to run so badly, I thought it was maybe some bad fuel. Drained the fuel and put in a new fuel filter. It barely runs, black smoke spewing out the exhaust, sulpher smell, coughing stalling etc.
I unplugged the Maf sensor and this is what has boggled my mind as I thought it would run without the maf well enough to get it to the shop.

With the maf unplugged, the engine runs great... but ONLY in PARK.
Within a half second of putting in any drive gear or even neutral, it will shut down just like you turned off the key. No sputtering stumbling, idling rough or nothing.
It will not start in neutral.
Put it back in PARK and it fires up instantly. Idles great. Revs up and down perfectly. No black smoke, missing etc.
Put it in drive and instantly shuts down.
I thought a vehicle would run with the maf sensor unplugged in a limp mode?
I have spent a week searching this forum and google searches and have found no-one with the same issue.
What the heck is going on?? I am literally at my wits end.

I feel like the only guy in the world whos vehicle will run fine with the maf unplugged only until you take it out of PARK.
Is there a way around this so I can get it to the shop short of trying a new maf sensor?
Any and all advise will be greatly appreciated!!

 

[swshawaii]

Trouble codes?

This should work on 1st Gen 91-94 Explorers and also 95 2nd Gen.
The 95 got a face lift but uses the same 1st Gen brain.

How To: Pull Trouble Codes on a 1st Gen Explorer (paperclip method)
http://www.explorerforum.com/forums/showthread.php?t=255962

 

[Randymann]

Trouble codes?

How To: Pull Trouble Codes on a 1st Gen Explorer (paperclip method)
http://www.explorerforum.com/forums/showthread.php?t=255962

Thank you for your reply. I will try and pull the codes tomorrow and post them.

 

[koda2000]

It makes me wonder if you got some diesel in your tank. I few months ago I was replacing a fuel pump, in my '00 XLT 5.0, and ran out of empty containers to put gasoline in when siphoning out a full tank of gas. I had a empty 5 gal jug that had diesel in it. It had been emptied, but a tiny bit of diesel must have remained in it. It couldn't have been much because I'd shaken the container before using it and didn't hear anything.

After replacing the fuel pump I refilled the tank and started the engine. It didn't want to start but eventually did. It ran like crap, smoked and didn't want to idle. I eventually got it to idle and tried taking it around the block. It ran like crap and pinged like crazy anytime you tried to give it any throttle. The more I drove it the better it would run, but the next morning it was back to not wanting to start or idle and smoking. I knew it couldn't be anything except fuel related, as the engine had been running perfectly (albeit intermittently) that morning before chaining the fuel pump and filters.

I deduced that that tiny bit of diesel fuel was messing things up more than I could have imagined. Cetain lowers octane and diesel is heavier than gasoline, so it sinks to the bottom of the tank (where the fuel pickup is).

I drove it this way until the tank was empty (carrying 2 1/2 gallons of premium gasoline with me). Once it was totally out of gas I put in the 2 1/2 gallons of gasoline and drove to the local BP/Amoco and filled the tank with premium fuel. It was fine after that.

You can't siphon all the bad gasoline out of your tank. There's always about 2 gals remaining in the bottom of the tank you can't reach with a siphon hose and, as the diesel settles to the bottom, you can't get at it.

I was amazed how a tiny bit of diesel could make the engine run so badly. It has to have been less than an ounce in 20 gals of gasoline. I'll never make that mistake again.

 

[J_C]

I wouldn't have thought it would cause black smoke, but I wonder if there was water in the fuel, with it also being heavier than gas so it sank to the botttom, and so I would put a container of drygas in the tank. You might also call the gas station and tell them your suspicions and ask if anyone else had a problem.

 

[Randymann]

I wouldn't have thought it would cause black smoke, but I wonder if there was water in the fuel, with it also being heavier than gas so it sank to the botttom, and so I would put a container of drygas in the tank. You might also call the gas station and tell them your suspicions and ask if anyone else had a problem.

There was a tiny bit of water so I put in some gas line antifreeze and the gas station said they had no others mention anything.

 

[Randymann]

Trouble codes?

How To: Pull Trouble Codes on a 1st Gen Explorer (paperclip method)
http://www.explorerforum.com/forums/showthread.php?t=255962

I couldn't even warm the engine up and had to pull the codes cold engine. There were so many codes, I will re pull them when I can actually warm it up first. So many codes, maybe the pcm is haywire? In any case, here are all the codes it came out with.

121
122
157
159
214
335
543
556

How the heck can a vehicle run great one day and all this the next. I still cannot understand this business of running only in PARK with the maf sensor unplugged? I've read 101 or more posts of people driving around with the maf sensor unplugged for days,weeks,months,years.
I could sit there and run through a full tank as long as sits there in the Park position??
I am looking up all these codes and my brain is now on overload. I cannot do too much right now as I had my Aerostar stolen with all my tools. I have not so much as a spark plug socket. No multi meter, nothing. The van was recovered, written off and no contents recovered. All I got back was the licence plates. Anyway, sorry for rambling on and on and getting off the subject. Like I said, my brain is on overload.

I forgot to mention, those codes were pulled KOEO.
I am almost afraid to get get the thing running and pull codes KOER.
I have only had the car about a month and a half. It can't be ready for the boneyard yet.

 

[swshawaii]

Start at the top (121-122) by testing your TPS. Borrow a voltmeter?

Ford Explorer - Ranger TPS Test Procedure
http://www.explorerforum.com/forums/showthread.php?p=2349296

 

[koda2000]

For what it's worth, I had unplugged the MAF sensor on my daughter's '00 Mountaineer 5.0L a few months ago (for the life of me I can't remember why... The only thing I remember it having a problem with was the cam synchronizer) but whatever the reason, I wanted to run the truck up on my ramps. While it as idling fine there was no way I could give it throttle and drive up my ramps with the MAF disconnected. I had to plug it back in to do so.

Keep in mind that when you get a slew of codes, like you're getting, it's often just one problem the will trigger all the other codes. Go through them logically and don't spend money on parts until you figure it out. I know it feels overwhelming, but try not to panic. I'm going to go lookup up the codes you're getting and see if I have any suggestions for you.

Edit:
You seem, to be having a lot of electrical related problems related to sensors being out of range. I agree with swhawaii. Get yourself a VOM and start testing stuff. As so many things are popping up, I'd also carefully examine your wiring harness. If all these sensors are part of the same harness maybe a rat or squirrel chewed up the harness. Seems odd it happened driving home right after buying fuel though.

 

[Randymann]

Start at the top (121-122) by testing your TPS. Borrow a voltmeter?

Ford Explorer - Ranger TPS Test Procedure
http://www.explorerforum.com/forums/showthread.php?p=2349296

I downloaded a lot of info regarding testing sensors. I live in a remote area and only have a couple of neighbors, Of course neither of them has a multi meter. I have to make a trip into civilization in about 9 days and will purchase a meter and like you said, start at the top with the TPS. I did swap the fuel pump relay with the a/c relay and tried pulling the codes again. Maybe because I pulled the codes on a cold engine would possibly account for the "voltage out of range" readings?( I am a newbie at this pulling codes business so I'm sure I am doing something wrong.) (And I do realize that the engine is supposed to be at operating temp, but it wouldn't run.)

These are the codes that came up after swapping the relays.
159
121
335
543
(repeated)
then after a pause:
111
111
then no more codes.

It then fired right up, but after having drained the fuel previously suspecting bad fuel and finding a bit of water, I was afraid to warm it up as it is almost right out of gas and didn't want to risk running it dry and possibly creating more problems. No gas stations around here, so fuel will also have to wait till the trip to town.Then I can do a KOEO and KOER with a properly warmed up engine. ( It does actually run now. ) In the mean time, thank you to everyone for your reply's, advice and patience with me. It is all very much appreciated!

I will post what I find out after I acquire a test meter and some fresh fuel.

 

[Randymann]

For what it's worth, I had unplugged the MAF sensor on my daughter's '00 Mountaineer 5.0L a few months ago (for the life of me I can't remember why... The only thing I remember it having a problem with was the cam synchronizer) but whatever the reason, I wanted to run the truck up on my ramps. While it as idling fine there was no way I could give it throttle and drive up my ramps with the MAF disconnected. I had to plug it back in to do so.

Keep in mind that when you get a slew of codes, like you're getting, it's often just one problem the will trigger all the other codes. Go through them logically and don't spend money on parts until you figure it out. I know it feels overwhelming, but try not to panic. I'm going to go lookup up the codes you're getting and see if I have any suggestions for you.

Edit:
You seem, to be having a lot of electrical related problems related to sensors being out of range. I agree with swhawaii. Get yourself a VOM and start testing stuff. As so many things are popping up, I'd also carefully examine your wiring harness. If all these sensors are part of the same harness maybe a rat or squirrel chewed up the harness. Seems odd it happened driving home right after buying fuel though.

Thank you for the post and I am thinking it must be just a coincidence that things went south right after getting fuel. As far as checking the harness, I think I had better do a very close inspection as when you mentioned a rat or a squirrel, it made me smile, as out in the boonies where I live, my closest neighbors are squirrels, chipmunks, raccoons, mice and yes, I have even seen a couple of rats that one of my cats insisted on bring home as a gift. And thanks to yours and other peoples posts, I don't feel as overwhelmed or in a state of panic like I was experiencing yesterday. Also, I just posted a reply to another post with some more info, ( It was a post originally Posted by swshawaii ) My post had a relay swap and some more codes in it.

 

[koda2000]

As I recall, getting codes from pre-ODBII Fords was quite involved (having to turn the steering wheel from lock to lock multiple times and other weird stuff).

As most ALL ODB codes are related to emissions problems, and you had so many codes related to multiple sensor readings, is what got me wondering about possible wire harness problems. Another thing that is known to cause problems is a bad alternator. Your's may seem to be charging okay, but they can sometimes cause spurious sensor readings.

Get that VOM and get to testing. Let us know what you find.

 

[96eb96]

I never really heard of a TPS going bad in modern cars (80s ones was common). Not to say it can't happen. Only a meter can test it.

What happens if you disconnect the Idle air control valve? Or just take it off a bit to let some air in . (tough to do without tools)
How old is your air filter? Plugs and wires?
Can you get MAF cleaner when you go to town?

The silver EGR dpfe controller or the solenoid could be shot too with those codes. It is on the left side with an electrical connector and two black hose lines.

Finally, like others said random codes could be a wiring problem or even a bad PCM.

I would go over all the vacuum connections as well. PCV, etc. You could have an intake manifold leak too.

Remove the EGR vac control line, plug it with something, start it up and see what happens.

How is fuel pressure? If you are near a harbor freight you could get an inexpensive gauge.

If you can get a cheap MT2500 red brick snap on scanner on ebay I believe you can read data streams on this car. The kits with older years are inexpensive. What ever it cost will probably be less than bringing it in. (100-200). Test the parts first.

 

[Harpua216]

have you checked your fluids? any antifreeze in the oil (looks like a coffee soda milkshake) or vice versa?

do you have spark on all cylinders? maybe you have good compression while in park but once you put a load on the engine, thing go wrong.

do you have propane or starter fluid, maybe carb cleaner? there are a lot of vacuum hoses and if i remember correctly, one that goes bad in the drivers side front, maybe to the brake booster or something, i cant remember but i put me bucking home and stalling a few times. for $3 in hose and some starter fluid to find it i was on the road...

.....and on to the next thing...mwah....

 

[koda2000]

Just an example of how common rodent damage is...

https://www.explorerforum.com/forums/showthread.php?t=445646