rough idle, overfueling, no codes

[stevek1873]

hello my name is steve i have 94 explorer i tried that ect sensor it helped but that wasnt exactly it .now it stays running instead of dieing write off ,but it stell running like crap an dieing,a freind told me to try the sensor on top of the fuel injection caseing something to do with oxygen sensor i think it is aic sensor , but it is stell spitting an sputtering an dieing like it is fireing backwards or jump time ,plugs ,egr valve , map sensor ,an ect sensor has been changed an coil has a pretty blue fire to it any more sudjestions ,im up for anything you have

 

[stevek1873]

hello!

I had the same problem on my 93 ranger (4.0l ohv). Same poor idle and running conditions. I cleaned the maf and replaced the ect sensor. No luck. So it turns out, even though the maf was sparkly clean, it wasn't sending the proper air information the the computer. The computer thought more air was entering the engine, hence the insanely rich mixture.

Imo, if its not the ect, change the maf. What do others think?

Good luck!

Erush

where is the maf located at ,i was told to try the sensor on top of the injection system

 

[mhallack]

I have a problem with the MAF, at least according to the shop that I bought my 94 Explorer at (they hooked it up to their monitor and it showed it was the MAF) I took it off and cleaned it, well it didn't really need much in the way of cleaning, but I still get the check engine light coming on after about 2 minutes or so of driving. It runs a bit rough and mileage sucks hardcore. It did have a bit of a problem when it would lose power when you kicked it into overdrive, though when they checked the code at the shop, it stopped the power loss, it will act normal when overdrive is kicked in. When I get the money I'll get it replaced, and get the other sensors eventually replaced too.

The MAF sensor is located up near the where you would replace the air filter.

 

[Dre]

Check your MAF to make sure it "belongs" to your truck - it might of been replaced at some point. MAF sensors are year specific.

 

[ERUSH97XLT]

Your MAF (Mass Airflow) sensor is located in-line with your intake tube, in front of the filter/airbox. There are multiple wires at the electrical connection (four I think?). All the others (i.e.: IAT) have only two. I don't have an image for you now, but I'm sure this forum has plenty if you do a search.

ERUSH

 

[doonze]

Check your MAF to make sure it "belongs" to your truck - it might of been replaced at some point. MAF sensors are year specific.

Not exactly year specific...but I would say model specific or at least engine specific....

When I found my junk one, I poured through a bunch of different ford vehicles looking for one that matched my part #, and from other's I've seen post on here I can tell you that at least they have the same part # stamped in the top of the sensor. 91-94 at least seem to be the same. In the end I finally found one on an explorer they had hidden in the back and seemed to have forgotten about (at least it wasn't with the others, was in pretty good condition, hope it wasn't one of the employee's daily drivers!!! LOL)

Anyway, it does seem it needs to come from a 4.0L at least, I think the one I pulled it from was a later model then a 94, different body. But the part # match excactly, and it works without a glitch!

 

[Rganther]

93 explorer eddie bauer

I kind of have the same problem as the original post. ROugh idle strong exhaust smell ,light black smoke, At times when trying to accelerate above 35 like there is nothing there,push the pedal and nothing let off pedal and power resumes, awfulsputtering coming from exhaust. Than sometimes you will hear this pop and it will idle and run fine than pop and back to same old crap.Replaced oxygen sensor today 65 bucks,not the problem,cleaned MAFS, not the problem, unplugged MAFS, idle went to normal, nasty exhaust dissapeared plugged in while running back to crappy, Went up and bought MAFS, 99 bucks, not the problemHELPPPPPP!!!!).Check engine light is not coming on.

Thanks for any help,

 

[mhallack]

Well I would say keep it unplugged, but I don't know if that will help permanently, or what would happen. I thought about doing that too, but figured the engine wouldn't run with the MAFS unplugged. Sucks you had to spend all that money and those items weren't the answer.

The shop were I bought my 94 XLT hooked up (for free) the computer and it said my issue was the MAFS. A local wrecking yard and parts place has a used one for $35 which I'm gonna get once I have the $$. I will be crossing my fingers that it's the only issue.

 

[doonze]

I had a MAF issue as well, ran with the MAF unplugged for almost a month, and it didn't catch on fire or anything.

I have a used one now from the junk yard, and problems solved. But yeah, you can run it unplugged.

I don't think we really know for sure, but I'm about 80% sure when the MAF is unplugged it goes into "open-loop" or default values for almost all sensors (I know for sure it does for the MAF at least). So what that means, in short, is if/when you unplug the MAF, and the problems stop, and you've replaced the MAF. Well, then, it's another sensor causing your problems.... Question is, which one? (Also keep in mind, just becuase it's a NEW MAF doesn't mean it's a GOOD MAF. I've read reports of people going through 3-4 MAF's new from the auto parts store until they found a good one.)

I would like to see someone who knows the PCM better (like a ford engineer, anyone know one?) post up with exacly what goes into "open-loop/limp home/failsafe" when MAF is disconnected and what doesn't. I don't think everything does, like crankPS. But I'm pretty sure eveything fuel related does (like O2 sensors)

Think of "open-loop" as fail-safe default guesses. Mostly on the rich side, to prevent engine damage. It's not good for MPG (mine didn't change much though) and it's not as good for the enviroment, but your not going to cause the next ice age by unplugging it.

EDIT:
Oh, also, it cuts the balls out of these things when you disconnect the MAF. Don't expect to win any drag races, and the throttle will seem a bit unresonsive, like you have to push the gas more to get a reaction. But other then that, it ran perfect.

 

[mhallack]

Earlier this morning I unplugged my MAF and drove around to see what if anything would happen. The idle went down to the point that I thought it was going to conk out and the check engine light came on almost immedetly. It drove like normal once I was moving, but just didn't seem right. So I have it plugged back and it's back to how it was running earlier. So once I have the money will get a used one.

 

[doonze]

Earlier this morning I unplugged my MAF and drove around to see what if anything would happen. The idle went down to the point that I thought it was going to conk out and the check engine light came on almost immedetly. It drove like normal once I was moving, but just didn't seem right. So I have it plugged back and it's back to how it was running earlier. So once I have the money will get a used one.

I forgot about the dying thing, yeah, mine died 2x while it was unplugged. And the CEL will come on seconds after turing the truck on, becuase the MAF is unplugged...

But it ran much better for me unplugged then plugged in, so I didn't complain about the dying too much. Course I have a standard, so the auto maybe worse about dying then the M5, don't know.

 

[Machine7]

Need Help

I have a 93 Ford Explorer will start but once I put in gear shuts off. Need help.

 

[physh]

thanks to the folks who gave advice in this thread, it has been very helpful.

 

[bispy]

I have a 93 ford explorer. The engine light comes on and off. It idles rough gets horrible gas mileage and no power. I took it to the only shop in town to have codes checked, three test later no codes. I cleaned the MAF with MAF cleaner. It still runs like crap. I'm sure it is over fueling for some reason. I'm getting alot of smoke, and exhaust smells like gas. any ideas. MY only idea left involves a cliff.

Ok my mate cliff will take it off your hands