Maf issues - keep having to replace -

[B2Mann]

Maybe someone here can give me some advise as to how to fix the issue i'm having. 91 ranger 4x4 4.0 5 speed. I've replaced the MAF 4 times in the last 6 months. Will run fine and get the usual gas mileage when the MAF has just been replaced. After about a month, the mileage begins to suffer and the truck will run poorly. I then run codes on said vehicle, and code 66 (MAF) pops up, unplug battery and replace MAF, and all is well. Swapped to a few different air filters with no change. Any help is some help. Really dont want to sell it, but this is becoming a pain.....

Any possibility putting a MAP sensor instead of having MAF? There is a MAP hookup for it. Thanks All

 

[cmequestionu]

How do all the wires and connectors look? Those kind of things might wear out after 20 years.

 

[B2Mann]

Why would the wires or connectors have anything to do with the MAF sensor being good at one point and time and going bad the next? I'll check them.

 

[alwaysFlOoReD]

Have you tried cleaning the maf with a sensor cleaner rather than replace? The first thing that popped into my head was the air filter, if you are using an aftermarket oil impregnated filter, over oiling can contaminate the maf.
Good luck,

Richard

 

[B2Mann]

Every time i've ever cleaned the MAF with MAF cleaner, code 66 still popped up. Just replaced MAF again(under warranty). Running fine as of now. Ran codes and states all clear. Not using an oil covered filter. No crappy K&N or similar products.

 

[shane96ranger]

I was going through some notes I have on some info I found for a Mustang of my buddies when we were trying to trace a surging idle.

It may be a bad ground, or like cmequestionu said, a bad connection in the harness. You can test things with a voltmeter to get an idea as to what it's doing. The pinout directly on the top of the sensor itself says A, B, C, D (at least the factory units do).

A: Power (12 Volts)
B: Ground
C: MAF Return Signal
D: MAF's Signal to the ECU

Unplug the sensor and do the following: Be sure the ground is a really good connection. Check and see if you are getting at least 11 volts to the sensor (voltage on A & B). I also believe the measurement should be 10,000 ohms or greater across C & D for yours as well.

If this stuff checks out, you may just be getting crap MAF's. What brand are you getting, not OEM I assume? Are they new or remanufactured?

 

[B2Mann]

I'll have to check the harness. The MAF is just one you can buy at Checkers or autozone. Not sure on the brand. Are there any other MAF's that are better?

 

[shane96ranger]

I'll have to check the harness. The MAF is just one you can buy at Checkers or autozone. Not sure on the brand. Are there any other MAF's that are better?

OEM is best, and a new unit would be much better than a reman. If you paid under $100 for it, the unit is most likely a reman.

EDIT: I just looked up Rock Auto's price on a Motorcraft unit: $105.79 + $75.00 refundable core = $180.79 - not bad for factory. (Check weezl's thread for a 5% off discount code too).

Check that harness out first and see what you come up with.

 

[shane96ranger]

One more question. Just for better understanding, is all of your intake set-up factory, and in the factory location?

I ask because a guy at work had some MAF issues on a 3.8 V6 Mustang with a professionally installed supercharger. He asked me to look at it, and I found the place had put the crankcase breather before the MAF, so it was caking it with oil. Not saying you did this, just throwing out ideas.

 

[B2Mann]

Intake tube is all OE. Crankcase breather tuber is after the MAF. It was a reman that I bought. I even had it switched with a new. I guess it just depends on the MAF. Right now, there is a reman on it, and it's working fine, no code 66. The MAF housing is bigger than the stock one that was originally on it. All wires going to MAF connector look fine.

 

[shane96ranger]

That's interesting the housing is larger. Do you know if the sampling tube (the tube the wires are in) is the same size?

 

[B2Mann]

Yup, sampling tube is the same size.