Changed the MAF Sensor and WOW what a difference !!!

[Rjj]

Thanks to all of you that helped me diagnose my Expo problems !!!

F.Y.I. I went to another part's shop yesterday looking for an inexpensive MAF. They had one but after an inspection...it was damaged also. What is it with these parts stores??? Four of them had damage screens and one had a core calling it refurbished and many didn't have them in stock. So I went to Ford... EXPENSIVE !!! But it works purrfectly!!!

The lack of power, surging, poor "first" starts, shifting problems... all are gone!!! When I push the gas lightly the Expo responds. It clearly runs better than ever!!! I would bet the old MAF was defective from the start because it always ran poorly. Until yesterday, I wished I would have kept my 91 Expo because it ran excellent... no more!!! To the poster that told me not to give up my Expo-thanks, you saved me alot of money and potential Durango Blues!!!

What is strange is that my engine light only started coming ON about a month ago but it ran poor the entire time I owned it. I tested the old MAF via the voltage tests and it appeared to work as the repair manual described it. However, the signal voltage would raise as expected but then drop slightly. This was enough to cause the poor performance of my Expo.

Thanks again !!!

ps. Any Expo/Jetboat owners are welcome to come visit my SeaDoo/Merc 240EFI JetBoater's Forum @ Dead Link Removed Threads are alittle thin given the time of year but in Spring... look out!!!

SpeedSter240EFI
Rj

 

[Mats E]

MAF

Where is the MAF sensor and what does it do?
What was the price?

Did you have any changes in mpg as well?

Regards Mats

 

[Rjj]

MAF

The MAF is attached the airbox where the air cleaner is. There are some wires coming out of it with an arrow pointing toward the engine intake.

It cost between $75 and $175. I have no idea why such a range but I studied my original MAF and made certain the new one matched perfectly and wasn't damaged. The screen should not have any damage.

Gas mileage, ahhh, couldn't tell you but I've been flooring it from every light and smiling. I don't care about the mileage right now. Also, I reset my computer after I installed the new MAS. So I would imagine the mileage would be poor. I am more interested in performance than mileage. When it performed poorly I cared about the mileage but now... not!

For $ 175... I have a new car!!!

SpeedSter240EFI
Rj

 

[410Fortune]

Dude I hope you tried cleaning the original MAS first, the drop in voltage is usually because it is dirty, not because it is defective.

I clean mine about every 3 months......

 

[Rjj]

Yes, I did... three times

The core I turned in looked like new it was so clean. There is no chance that dirt played a role. Even the screen material was shiny. The MAF would drop voltage and made the engine run like crap.

It is too cool to buy and install a "part" and the engine runs better than ever!!! It is PFM!!!

Thanks for your help...
SpeedSter240EFI
Rj

 

[98 exploder]

what brand of MAF did you buy? 175 $ seems really cheap beacuse the ones that I have been looking are like 300.
Glad to here that it fixed your perfromance problem

 

[Rjj]

The MAF was 165 plus 75 core charge

The Ford dealer commented as I returned the MAF core about 15-20 minutes after I purchased the refurbished unit. I should have did the repair in their parking lot...LOL and brought the core in about 4 minutes.

It is amazing how critical the function of the MAF is to the engine/tranny performance. A defective MAF can really F#%# up the Expo.

It is a really simple repair. However, I tested most all sensor before I replaced the MAF. There are nine or so sensors on my 4.0L engine, maybe more I haven't found hehe. It would get rather expensive to shotgun/replace the sensors! So take your time to determine the problem before blowing your cash!!!

This forum has been very helpful Coming from a newbie of Expo repair... make certain your tests are performed correctly and trust the results along with the recommendations from this board You will soon be smiling as I am!!!

SpeedSter240EFI
Rj