MAF Problem

[lincolnchuck]

So my car a 1995 4x4 V6 4R was running rough like not idling well when it was cold and would die when put it in to gear. But after it was warmed up it would run like a champ with no problems.
So i felt like it was the MAF sensor so i took the air filter out and disconnect the whole top of the air system and then disconnect the metal part form the plastic and then cleaned the inside of the intake and sensor area. I also messed with the terminal connection like unscrewing it. Not sure what i did but now it wants to start and then die after like 3 seconds of running. please help i have no clue whats up. i even disconnected the battery.

 

[rustyrazor]

Is the check engine light on?

If the check engine light is on you could read what code it puts out.

I know that some parts stores like advanceauto will read the code for free.

I'm almost wondering if it's a fuel delivery problem. Maybe a clogged fuel filter or bad fuel pump.

Often the system can work just well enough to pressurize when you turn the key on but then can't keep up once the engine starts.

 

[Brand X]

Here's a way to check the maf by hand. Take the plastic cover off the top of the maf, then move the needle under the maf cover slightly left and right to see if the idle levels out. If you can't find a good center then it's probably not your maf. check your vaccums and your fuel pressure regulator.

 

[Iroke17]

-- removed by admin --

 

[alerma]

So my car a 1995 4x4 V6 4R was running rough like not idling well when it was cold and would die when put it in to gear. But after it was warmed up it would run like a champ with no problems.
So i felt like it was the MAF sensor so i took the air filter out and disconnect the whole top of the air system and then disconnect the metal part form the plastic and then cleaned the inside of the intake and sensor area. I also messed with the terminal connection like unscrewing it. Not sure what i did but now it wants to start and then die after like 3 seconds of running. please help i have no clue whats up. i even disconnected the battery.

you did what i did today, unscrewed the connection to the MAF, my 95 has been running like a champ...check engine light came on so i figured i would clean the sensor...thought if i unscrewed the sensor from the MAF body it would be so easy, what i did not know is that i ripped out three of the pins soldered to the circuit board...now im trying to find someone to re-solder them to the board or i have to find a junk yard for another MAF body...

 

[runnerhuh]

How where you able to determine you pulled the pins out? I may have done a similiar action recently. I would like to clean the mass air flow sensor but am not seeing the best way to get to it to clean it. Does anyone know the best way to spray it out and clean it? I have the sensor spray but not sure how to access it. Thanks.. :frog:

 

[Bad_Vision]

well the proper way to clean it is to take it apart and clean it, if you dont have the know how to do that you should just buy a replacment.
It is like taking apart a computer you need to be careful and label everything you take off. soke all the parts in the cleaner and wipe with cotten swabs in the hard build up spots.

 

[astynx]

maf issue

So my car a 1995 4x4 V6 4R was running rough like not idling well when it was cold and would die when put it in to gear. But after it was warmed up it would run like a champ with no problems.
So i felt like it was the MAF sensor so i took the air filter out and disconnect the whole top of the air system and then disconnect the metal part form the plastic and then cleaned the inside of the intake and sensor area. I also messed with the terminal connection like unscrewing it. Not sure what i did but now it wants to start and then die after like 3 seconds of running. please help i have no clue whats up. i even disconnected the battery.

This should be a sticky "DO NOT UNSCREW 2 SCREWS OF MAF SENSOR ON TOP OF AIR CLEANER COVER. The maf sensor connection has a fine 'paper clip thickness wire on each vertical side of maf sensor plug.This isn't readily apparent when you look at the plug. You gently push the top of each wire a slight amount (1/8th inch) to each side as you look at maf sensor, then maf sensor plug unattaches very easily. How to actually unconnect this connection is not explained in any repair manuals that I personally researched. To conclude- bad news your truck won't run, good news- trip to salvage yard with top of air cleaner cover and integrated maf sensor and find replacement from any 90-95 4runner. To save time don't bother with separating maf sensor from top of air cleaner cover. Unhook large intake hose, small hose at front of air cleaner cover, unattach maf plug and a few bolts to remove cover and sensor. I learned this from personal experience. I thought it would be a good idea to clean maf sensor. When I bought maf sensor cleaner at auto parts store. I mentioned to person that maf sensor doesn't look like it unplugs but there are 2 little screws though. He said " unscrew screws and pull sensor. DON'T DO THIS!

 

[hotrodz]

Frustrating Mistake

:sadwave:

This should be a sticky "DO NOT UNSCREW 2 SCREWS OF MAF SENSOR ON TOP OF AIR CLEANER COVER. The maf sensor connection has a fine 'paper clip thickness wire on each vertical side of maf sensor plug.This isn't readily apparent when you look at the plug. You gently push the top of each wire a slight amount (1/8th inch) to each side as you look at maf sensor, then maf sensor plug unattaches very easily. How to actually unconnect this connection is not explained in any repair manuals that I personally researched. To conclude- bad news your truck won't run, good news- trip to salvage yard with top of air cleaner cover and integrated maf sensor and find replacement from any 90-95 4runner. To save time don't bother with separating maf sensor from top of air cleaner cover. Unhook large intake hose, small hose at front of air cleaner cover, unattach maf plug and a few bolts to remove cover and sensor. I learned this from personal experience. I thought it would be a good idea to clean maf sensor. When I bought maf sensor cleaner at auto parts store. I mentioned to person that maf sensor doesn't look like it unplugs but there are 2 little screws though. He said " unscrew screws and pull sensor. DON'T DO THIS!

I just did the same yesterday on my 95 runner, unscrewing those two screws appears to be a forbidden act.

It was running fine except for a bit of shaking at idle when in gear, but the check eng. lt. came on and the lean code 25 diagnosed. I inspected all the hoses, replaced the PCV/ hose, but the same condition remained. Thought of cleaning the MAF and when I got to the connector terminal screws, unscrewed, pulled a bit thinking it would unplug but to my surprise I then realized that what I did was ripped off a couple of pins from the electronic board after deciding to break the plastic cover silicone seal. I had a friend solder the pins back on but it dies 2 or 3 seconds after it starts. The slider travels only about halfway during this attempt to start. I checked for voltage at the connector and it is feeding the 5 volts to one end and 12 volts on the other. I guess that the answer is MAF replacement.:sadwave::sadwave:

 

[monkphish]

95 'runner MAF

My 4runner started fine, idled great, but when i got up to 3 gear or so the check engine light would come on and the engine would just bog down with loss of power. I ran through everything- changed fuel filter, SP wires, D-cap- no improvement. Did a visual inspection of the MAF sensor and it looked fine. Like everyone here i took the 2 screws of the housing and ripped the terminals out of the board. Luckily, i do electronics and PC repair so no biggie. I ended up leaving the sensor (2black wires with terminal connectors) off and it is back to running like a champ!

Anyone know of the disadvantages of leaving the MAF sensor disconnected if any? I was getting about 10 mpg, now i'm back to 18+, doesn't seem to be hurting anything. I figure i would put a resistor of the same ohm reading as a good MAF sensor to keep the check engine light off if there is no harm. Thanks y'all!!

 

[aj884runner]

Always wondered what would happen if I removed those screws. I have a couple of spare sensors to try this.

 

[PHeff89]

MAF Swap out

Anyone know if there is a way to swap out the MAF on a 1994 Runner 3.0l 3VZE engine? I can hear a horrible noise coming from mine like its sucking air and want to replace it before it goes kaput but the ones for a 94 are like 140-150 $$ but the one for a 1998, which is much smaller by the way and would look alot nicer with my CAI, are like 40-50$$??????? Help???:ballchain:fftopic:

 

[flyinhawaiian01]

Short answer, no.

They don't have the same electronics, and will not mate up even if you rewired it to work.

Not sure what you mean by it sounding like its sucking air, as that's sort of its job; the engine pulls air through the flapper door, which in turn tells the ecu how much air volume is being passed through at that moment. It also tells the fuel pump to turn on when there's air passing through the door.

I would pull the stock maf apart, clean it up and see if something like a leaf or plastic bag is stuck inside of it. They don't normally go bad, even though they have moving parts and electronics in them.

 

[Dean2]

:sadwave:

I just did the same yesterday on my 95 runner, unscrewing those two screws appears to be a forbidden act.

It was running fine except for a bit of shaking at idle when in gear, but the check eng. lt. came on and the lean code 25 diagnosed. I inspected all the hoses, replaced the PCV/ hose, but the same condition remained. Thought of cleaning the MAF and when I got to the connector terminal screws, unscrewed, pulled a bit thinking it would unplug but to my surprise I then realized that what I did was ripped off a couple of pins from the electronic board after deciding to break the plastic cover silicone seal. I had a friend solder the pins back on but it dies 2 or 3 seconds after it starts. The slider travels only about halfway during this attempt to start. I checked for voltage at the connector and it is feeding the 5 volts to one end and 12 volts on the other. I guess that the answer is MAF replacement.:sadwave::sadwave:

I know this is an old thread but the problem keeps coming up. To disconnect the AFM look VERY closely and you will see two fine wire bits on the plug BEFORE the two screws holding it to the housing. Use a fine bladed screw driver and push the wire clip out on both sides. Once it is free of its grooves the pug will come off very easily with no damage to the AFM.

If you did take off the two screws and now the truck just cranks and won't start, you aren't completely screwed. The connections inside this housing are very fine and easily moved causing them to contact where they shouldn't or not contact where they should. Take off the plastic cover to the AFM by cutting through the silicone and GENTLY prying the cover off. First step, turn key to on, move large rehostat counterclockwise, door starting to open, so the fine needle connected to terminal FC contacts E1, ist and second terminals,on the far left. As sonon as it makes contact, you should hear the fuel pump fire up. So far so good. TURN OFF AND REMOVE KEY.

Now use a good magnifying glass and make sure that none of the little soldered on tips are touching each other and that they are resting only on their part of the circuit board.

You can also tell using a Ohm meter. If the reading between terminals E2 and VC or VS is zero, whereas they should be 200 or more ohms, you have two parts touching that shouldn't be. Carefully pull the sensor clips part way out, you can disconnect the three spade clips to remove it completely but you need to have a gentle touch and use only your finger, this is no place for piers, Align the very fine and easily movable soldered tips so they rest directly under their terminal and do NOT touch the terminal or circuit board for the terminal beside it. You should be back to having the proper ohm readings.

With the terminals partly or completely removed so they don't touch the circuit board, you can also test the circuit board itself by touching the appropriate landing pad under each terminal. As long as the circuit board is giving you the right ohms between terminals it is just a matter of delicately getting each terminal to completely rest on its pad and its pad only. Voila, back to a working AFM.

Hope this helps all of you that removed the screws before realising that isn't how you unclip the AFM