Mass Airlflow Sensor Problems

I recently installed a 75mm mass air flow sensor from Mass Air Systems on my '94 X. To begin with, it would constantly stall at start-up and any time I stopped. I could smell gas and it seemed that the engine was running rich. There was also black soot on the tail pipe. I called MAS and talked to one of the guys there. He said that the unit was calbrated to run using a conical filter and my problems were due to the stock air box being used. I found a 3" IFAB cold air intake system on eBay. I installed the cold air system and left the battery disconnected an hour to clear the computer (not sure if this did any good but though it was worth a try.) Initially, I had the same problem with stalls, however over the last month, the engine has been running better, although it feels like I have lost some low end torque. It hardly stalls unless it is very hot outside or I turn on the AC right after I start the engine. There is still soot on the tail pilpe and my mileage has gone down significantly since installing the MAS. Given all this, I am wondering if the MAS is incorrectly calibrated. I called Mass Air Systems again but nobody is returning my phone calls. I am about ready to pull the unit off and put my stock sensor back on. No use using the MAS if all I am doing is running excessively rich. Any ideas or suggestions?

 

[aldive]

First of all a 75mm MAF is too large for your OHV motor. Further, more than likely it is not properly set up for your motor.

Stock Ford MAF electronics are very good. You might want to try a MAF housing from C & L with the stock electronics.

This system works great for me; take a look at http://www.explorerforum.com/forums/showthread.php?t=136883&highlight=maf

Contack James Henson to get one ( http://www.hensonperformance.com/ ).

Good luck ...

 

[luvmonterey]

Thanks for the info. I checked out the website but I could not find a 73mm MAF for the 4.0 OHV, which I have, as my X is a '94. Is it the same unit as 5.0? That does not seem right though. I don't understand why MAS would go to the trouble of building a larger MAF it is too big for the 4.0 OHV and does not work well. They swear up and down it is the right unit and is calibrated properly.

I am wondering if I should swap out the electronics from my stock unit and install them in the MAS unit? Any thoughts on that? Other than that, I'm not sure what to do at this point other than keep trying to reach MAS for assistance.

 

[Turdle]

If this is who you are dealing with--

http://www.massairsystems.com/

Man have I got a story for you--

or-to keep it short--ditch it.

The very first sentence on the page is a lie!!!

 

[aldive]

I was being nice; however, Jon, is correct, avoid these folks.

Contact James for the roper 73 MAF.

 

[luvmonterey]

I removed the 75mm unit this weekend, and left the battery disconnected for about an hour. I left the cold air intake with the cone filter on, and just swapped in the stock MAS. However, now whenever I push down hard on the gas, my engine pings like crazy! I don't know what to do! I have no idea why this is happening. Anyone have any ideas?

Thanks for the heads up regarding Pro-M. I purchased the unit from Explorer Express so I will have to deal with them in order to get my money back. Unfortunately, when I first started having problems with it, Explorer Express told me to call Pro-Mass, but I hope that they will be reasonable and refund my $$.

 

[luvmonterey]

Jon, what is the story with Mass Air Systems (Pro-M)? Sounds sinister....

 

[Turdle]

Well, to shorten it a bit, and not include the burned #4 piston in the first 347

start with post 98

http://www.explorerforum.com/forums/showthread.php?t=167231&page=5&highlight=surging


post 104 might interest you also--

 

[jah81592]

73MM maf

I don't currently list the 73 on my website. It is under construction, not all parts are listed. If you need one then let me know and I can order one for you. I will send you a secure link to order.-james

Calibrated meters are for the birds. And Pro-M is even worse! Stay away from them. Aldive is correct get yourself a C&L and you will be happy. Contact me at hensonperformance@bham.rr.com

 

[luvmonterey]

Thanks James. I need to contact Explorer Express and try to get my $$ back for this piece of junk Pro-M they sold me. I would like to get one of your units though. They are nice people but man, I have had nothing but problems with this Pro-M unit. They sent it to me the first time with a six pin connector and my '94 has a four pin. Just went down hill from there.

Any idea why my engine is pinging under load now that I have swapped the stock MAS back in? I did leave the conical filter and cold air kit on rather than using the stock air box and runner. Could that be the problem? Thanks!

 

[jah81592]

Thanks James. I need to contact Explorer Express and try to get my $$ back for this piece of junk Pro-M they sold me. I would like to get one of your units though. They are nice people but man, I have had nothing but problems with this Pro-M unit. They sent it to me the first time with a six pin connector and my '94 has a four pin. Just went down hill from there.

Any idea why my engine is pinging under load now that I have swapped the stock MAS back in? I did leave the conical filter and cold air kit on rather than using the stock air box and runner. Could that be the problem? Thanks!

I would get some contact cleaner and clean the "resistor" in maf. If it is dirty it will cause problems from funky idle to lean. I will tell you I had a 1991 and I always had to run at least 89 octane. For some reason it just ping all the time.-James

 

[Jakee]

I would get some contact cleaner and clean the "resistor" in maf. If it is dirty it will cause problems from funky idle to lean. I will tell you I had a 1991 and I always had to run at least 89 octane. For some reason it just ping all the time.-James

I can finally say I KNOW WHAT YOU MEAN JAMES!!!!

I had a 91 explorer first, and that thing pinged like a woodpecker. I'm suprised I didn't blow it up...Nice me gave it to my sister and she totaled it.

 

[RickOTR]

That is why Pro-M is out of business... junk! I got a 75mm MAF sensor housing from a Ford Mustang Cobra and used the OEM MAF sensor from my Explorer. I then had a friend of mine reflash the ECM for the MAF and 24lb fuel injectors I installed. The engine purrs like a kitten. 75mm is way to much for 19lb injectors and stock ECM (fuel system will go way to lean). I woud go with a 73mm MAF and get a computer chip burned for the sensor.

 

[luvmonterey]

Rick, When you say "get a chip burned for the sensor", are you talking about the MAF? I have a '94, and have heard that they are much less able to be reprogramed.

I removed my MAF electronics last night and cleaned the filament with electronics cleaner from Radio Shack. The sensor was really dirty. However, now the truck will not idle at all, and will not start and hold an idle unless I keep the gas pedal pressed. After driving for a while, it will hold an idle at about 500 RPM, but frequently stalls. There is no more pinging now on acceleration or hill climbing, so at least one issue is resolved. Anyone have any suggestions? I have not removed the IAC to clean it yet.

 

[aldive]

I would try cleaning the IAC, but I have rarely found it to work; be prepared to purchase a new IAC.

 

[luvmonterey]

I removed the IAC and cleaned it per the instructions from this site. It worked! At least is seems to be running much better. Thanks everyone that responded.