MAS??????

[Daniel K.]

I read the article about the MAS needing cleaning. I belive that mine needs this done to it. But i don't understand the star security screws?? Before i attempt this Dad wanted me to ask what and where such a thing can be bought? any info is appreciated

 

[murrajm5]

NAPA is where I got mine from but there are probably many others.

 

[Jeff S]

You can buy a security bit/screwdriver at most auto parts stores, but I didn't even need one. I used a pair of pliers to carefully loosen and tighten the screws. Worked just fine!

 

[Daniel K.]

ok i got some of those stars and took apart the air filter box. Mine is a circular box if it makes any diference with the MAS inside one half. I couldn't get to the two screws holding the wiring harness in because i couldn't get it out of the air filter box. The wires run through the box and to the MAS. I'm planning on putting a KKM on and will need to get it out. HOW??? Any advice.
Another question is i cleaned the filaments by taking the plate held by two of those screws off the back and you can then see the filaments. My question is if i leave that plate off would it increase the air flow??

Any advice from passed experiences?? Thanks

 

[wilk1]

Got mine from the 99 cents only store and it came with 5 other bits, works great!

 

[Rhett]

I tell you one thing...I cleaned my MAS today, and it just about cured the ping I was getting at partial throttle. Not completely, but I still have more to do, like new plugs and wires...

And, cleaning the MAS seemed add some muscle when I accelerate. I really noticed the difference on an interstate on-ramp. I used STP O2 safe throttle body/sensor cleaner.

 

[Empty Pockets]

Me too

I've read much about pinging but this is the first time that anyone has mentioned partial throttle. That's what I have, a ping only at light throttle (low rpm's). It usually happens over 30 mph even as high as 60 mph- when the transmission has shifted so that the RPM's are down around 2k and I give is some throttle to get up a hill or to increase the speed it pings. Unless the tranny downshifts and the rpm's go up- then it doesn't ping.

I've also noticed that it pings in "Park" when it is punched from idle (I was under the vehicle looking for another problem when my wife was at the throttle).

It's a '94 with about 100k on it The plugs and wires are pretty new and I recently cleaned the MAF Sensor & the throttle body. I haven't checked the head bolts- the dealer told me that they replaced the head gasket under warranty (when I got it at 70k).

I'm concerned about this now because I think that higher octane gas isn't fixing the problem and I tow a boat.

Should I check the head gasket bolts? Any other Ideas?

Rhett, if you have any success please let me know.

 

[Rhett]

I put some 89 octane in, and it's pinging again under partial throt. I think my O2 sensors are bad, I wonder if that has anything to do with it?

It should be able to run 89 octane. I have reset comp and cleaned MAF and cleaned my K&N. Next thing is new O2s, plugs and wires.

Got my new Jacobs wires in today. I should have enough time to mess with that this weekend. If it helps it I will repost here.

 

[Rhett]

By the way, Empty Pockets, that is exactly the same ping I am getting...partial throt at 30 mph+.

When I pull the 5th plug I'll look for carbon or oil deposits in case the gasket is leaking oil in there...

 

[rednose]

Originally posted by Daniel K.
I read the article about the MAS needing cleaning. I belive that mine needs this done to it. But i don't understand the star security screws?? Before i attempt this Dad wanted me to ask what and where such a thing can be bought? any info is appreciated

I have a 98 sohc and I have cleaned mine a couple of times by just taking the clamps loose and then using a Q-tip and a little rubbing alcohol, look inside the mass tube from the intake side and you will see two wires that look like little siver pins shrouded on three sides by a plastic housing, be very easy with the Q-tip and rub the wires and check to see if you get any black stuff off, I never did and ended up replacing the unit for 250 bucks from ganatelli motorsports, it made cold starts and general driving much better, E-mail me if you need the part number or the web site, make sure that when you do this that you dont get to rough with the connecters the plug into the mas unit.

 

[gene kirkland]

Did you say you cleaned the throttle body? If so I cleaned mine and it ran like crap afterwards! Pinging and loss of power. I replaced the throttle position sensor and the performance is bac to normal

 

[ahughes]

I had been noticing an irregular idle recenly at cold startup. It would go away after warm up. I reset the computer with no positive result. Rough idle continued. We have had the swing in ambient temp. lately +/- 30F. Today my wife calls from about two hours away, the Explorer is stalling. Uh oh'. The truck made it home, thankfully.

I stopped on the way home and bought STP throttle body cleaner. I took the entire air box and tube assebly apart. I did'nt fool with the MAF star bits. I just douced the air molecule elements from teir exposed end with the cleaner fluid leaving the MAS intact in its aluminum housing and let gravity do the rest in draining out the excess fluid.

Next, I douced the throttle body with the cleaner. Out ran the typical brownish varnish and buildup. I would suggest parking on a grade with the front of the truck aiming downward. This will promote any fluid from going past the throttle body and drain outward. I carefully wiped away any loose residue. I let the cleaning fluid do the work, minimum wiping

When I started up the engine I could tell a remarkable difference in the tune of the engine. I raced it around the block and all is well.
I would bet that a lot of runnabilty issues regarding the SOHC can be attributed to a dirty TB and MAF. Finally, I changed the air cleaner. BTY, the truck has 53K on the clock and was past due for this service. I will do this every other oil change from now on. Happy motoring everyone.

 

[Empty Pockets]

Rednose,

I'm glad to see that worked but why did you choose to replace the MAS in the first place?

Gene,

What made you decide to replace the throttle position sensor?

 

[Rick]

Re: Me too

Originally posted by Empty Pockets
I've read much about pinging but this is the first time that anyone has mentioned partial throttle. That's what I have, a ping only at light throttle (low rpm's). It usually happens over 30 mph even as high as 60 mph- when the transmission has shifted so that the RPM's are down around 2k and I give is some throttle to get up a hill or to increase the speed it pings. Unless the tranny downshifts and the rpm's go up- then it doesn't ping.

I've also noticed that it pings in "Park" when it is punched from idle (I was under the vehicle looking for another problem when my wife was at the throttle).

It's a '94 with about 100k on it The plugs and wires are pretty new and I recently cleaned the MAF Sensor & the throttle body. I haven't checked the head bolts- the dealer told me that they replaced the head gasket under warranty (when I got it at 70k).

I'm concerned about this now because I think that higher octane gas isn't fixing the problem and I tow a boat.

Should I check the head gasket bolts? Any other Ideas?

Rhett, if you have any success please let me know.

There is a thread about loose intake manifold bolts causing pinging due to a small amount of oil being drawn into the intake port and building up deposits. The easiest fix is to just try and retorque the bolts of the lower manifold. Beyond that is replacing the gasket.

 

[rednose]

the mass

I chose to replace it because I heard the aftermarket one was not prone to heat problems, mine was having all the symptoms of one the was getting too hot and sending wrong signals, it gives more acurate info to the computer or so they say, I took it in twice before replacement and they couldnt find any codes or any reason for my problems except that it might be sending false signals.