1995 3.0
Engine will start, but idle very rough and try to die. Once warm, the engine will idle, but it's very rough. In "PARK" and holding the gas pedal/RPM at typical highway speed the engine has a bad miss. The exhaust stinks.

Unplugging the MAF sensor will make the check engine light come on, but the engine will then run very smoothly. As soon as I plug the MAF back in it will idle rough and try to die.

What am I doing when I unplug the MAF? Where should I start looking for the problem?

 

MAF element is dirty or broken
try cleaning first, search Aero forum for MAF cleaning

http://www.muscularmustangs.com/maf.php

pull codes and please post
http://fordfuelinjection.com/?p=13

MAF sensor element or heater may be broken or burned out.

 

When you unplug the MAF, the computer resorts to default settings for the air/fuel mix. Since it runs well in this condition, it is safe to assume the engine is mechanically sound.

When connected, the MAF sensor is reporting incorrect airflow into the engine. The computer adds the amount of fuel it expects the engine will need, but it is sufficiently off that the engine runs poorly and the exhaust stinks (sulphur/rotten eggs?).

The hot wire in the MAF sensor is probably dirty. There have been many threads in this forum which detail how to clean the MAF sensor. Use the search function to look for these. If cleaning doesn't make an improvement, you may need to replace the MAF sensor.

If cleaning does help, you should check to make sure the air filter is clean and sitting in the housing properly. Also note that the oiled gauze air filters (K&N, etc.) are known to contaminate the hot wire.

 

Ok... my brother put a new alternator on this van a couple months ago, and it hasn't ran right since. Now, fast forward to tonight... per advice given in this thread, I started to inspect the MAF for a possible problem. The first problem is the clamp that holds the rubber intake tube to the MAF wasn't tight at all... making a nice air leak. Now is when it gets good... he put a shop towel in the MAF sensor to "keep mice out" while replacing the alternator and forgot to remove it when he was done!!! Lol, the aggravation that someone else's silly mistake has caused me! Anyway, my Dad is glad his van is running right again, and thanks to all who replied

 

a mouse thru the engine air intake and out the exhaust is far worse than a cat thru the fan

cat quits howling after a few minutes, mouse pellets just keep rattling

 

... accept that the maf has a built in screen on it to keep mousies out?

 

How much is MAF? Just replace and that is all, forget about it for next 10 years (if you replace air filter in time)....

 

The MAF on my 4.0L actually went bad a few months back. I tried cleaning it several times but without luck. I bought a used one on Ebay for about $30 and that worked great. You just have to make sure it has the same part number and the correct version number.

 

The MAF on my 4.0L actually went bad a few months back. I tried cleaning it several times but without luck. I bought a used one on Ebay for about $30 and that worked great. You just have to make sure it has the same part number and the correct version number.
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Yeah, there are different versions of MAF, with small film inside ore with nicel-chrom hair ore othe type....

ECM is parametrized for relevant MAF.

 

Man I love this forum!!!

I need a MAF sensor for my 89 4.0 aerstar.
Long story: I broke while cleaning it!!!!!!!!!!!

I think found one on ebay out of a 4.0 explorer:
Does anyone know if this would fit:
Here are the numbers on the MAF:
PBT-GF30
F57F-12B579-AA
5E25

and here are the numbers on mine:
ABCD
F07F-128579-AA
AFH55-05
9D28

Thanks

 

the first year the 4.0L V6 was avail in the Aero was 1990
you sure you have a 89 with 4L? may be a DIYer changeout?

go to RockAuto. com site sponsor for the best service and exact part for your MAF, best prices also. super fast service and shipment

don't use the Ranger MAF, for an OBDII EEC-V system

 

Oh YES it is a DIYer.. I bought it from a friend of mine in 1997 and everytime I see him he tells me something that has been changed out on the van.. I forgot that the engine was swapped.. but I got it for a good price and it still runs well..

MAF I list was suppose to be from a 4.0 explorer.....

Could it be possible that the MAF on my van is from the 3.0 engine????

I was hopping to get a used one, cash it tight right now..
But I will check out rockauto.com

Thanks

 

the pre 96 Aero 4Ls call for a F07F-12B579A2B
any MAF from 4L ranger, explorer or aero pre '95 should be fine.

used MAFs are a shot in the dark. if left out exposed at junke yarde partse emporium, they often corrode electrically. air flow rate calibration may be wrong from corrosion

from cross reference use same MAF
FORD AEROSTAR (1990 - 1995)
FORD EXPLORER (1992 - 1994)
FORD RANGER (1990 - 1994)
FORD RANGER SUPER (1990 - 1994)
LINCOLN TOWN CAR CARTIER (1991 - 1992)
LINCOLN TOWN CAR EXECUTIVE (1991 - 1992)
LINCOLN TOWN CAR SIGNATURE (1991 - 1992)

 

I would just buy a new one.
At RockAuto, they have rebuilt units ranging from $104-$166 depending upon brand.

All the choices they list would be good, though I would lean towards Cardone or ACDelco.

In any case, don't buy a used one.

 

Guys:

Thanks for the cross references and all the advice....