Pretty sure my MAF is pooched on my VR4. Got in it to grab a friend and touched the throttle and it died. Start it up, put it in drive, touch throttle and it dies. Won't rev in neutral, drive or park. Pulled the plug on the MAF and it ran kinda like crap but it revved fine. Good thing it didn't do this after I got to the airport 30km away.
MAF shot?
- Thread starter Tempast
- Start date
naughtika
OzVR4 Stalker
Pretty sure few members here do sell 2nd hands
Try cleaning it with this if you can
http://www.carmodsaustralia.com.au/upper-engine-cleaner.html
http://www.carmodsaustralia.com.au/upper-engine-cleaner.html
- Thread starter
- #5
So I plugged it in, drove it home and it drove fine. I took my Subi to work and grabbed a can of MAF sensor cleaner and cleaned the MAF and haven't had another issue in the last few days. Not sure if it was a little hiccup or what. MAF looks in good shape, no damage, connector isn't damaged and from what I can see the pins are in good shape. I'll post again if it acts up. Hopefully not.
Sorry to hijack this thread but apparently I dont have enough privilege to start a topic?
I wanted to know if MAF sensors are interchangeable between galants? I have a VR4 1999, would I be able to use a MAF from a 1.8L? Or what alternatives do I have? Ta.
I wanted to know if MAF sensors are interchangeable between galants? I have a VR4 1999, would I be able to use a MAF from a 1.8L? Or what alternatives do I have? Ta.
Post an intro thread and go from there i.e. follow-up with a WTB post... I'm sure someone will help you out
Tony_T
Leaving Skid Marks
Cleaning won't fix it.
The MAF is easy to repair if you have any soldering skills. I posted a full description of what fails and how to fix it somewhere here but now can't find it, so if you don't mind the read, here it is again in all its glory:
The hardest part of the repair is getting the top lid off without breaking any of the four little plastic tabs which hold it on. In my case it seemed that there could have been a bit of silicone sealant also keeping the lid on which made it harder so I ended up breaking two of the tabs and having to improvise some clips to take their place. So, remove the MAF from the car and if you like, dismantle it from the plastic airway parts to make it easier to handle. Then remove the lid. Under the lid you'll see a metal shield which is held in place by springy tabs. Just ease the shield out, try not to bend it so it will fit back nicely later.
NOTE: the purpose of the shield is to prevent any radio frequency signals nearby from affecting the operation of the MAF. Test at idle with it removed but DO NOT take the car onto the road without it in place: I do not accept responsibility for any crashes caused by sudden changes to the car's operation while driving due to some nearby radio emission e.g. your cellphone!!!!!
Our MAF works by the incoming air which has had turbulence caused by the special inlet and shaping passing over two heated wires causing their temperature to vary. As with most metals the electrical resistance of these wires is temperature dependent so we have a variation of resistance in response to the airflow. To allow this resistance change to be measured accurately the current which flows through the wires to heat them must be carefully regulated. This is accomplished by having a precision resistor in series with each wire, the voltage which appears across this resistor is compared with a reference voltage in some simple electronics and the resulting error signal is used as feedback to the current control transistors. This means that when the car is switched on these resistors also heat slightly due to the current flowing through them, and when the car is switched off again they cool. As with most things they expand and contract slightly with this heating and cooling. They are soldered to copper tracks on a fibreglass based circuit board which has a different amount of thermal variation and this causes stress to be applied to the solder joints at each end of these resistors, eventually causing the solder to crystallize and become an intermittent connection which is very susceptible to vibration. In my case the car would often idle but when any throttle was applied the vibration caused the contact to make and break rapidly giving extra pulses from the MAF to the ECU. The ECU saw this as heaps more airflow and ramped up the fuel to the point where the mixture would not ignite stopping the engine and producing rather a lot of black smoke occasionally.
The repair:
I'm assuming you or someone you'll get to do this for you is confident with soldering of electronic components:
Locate the two larger resistors which are flat rectangular items on the circuit board towards the top right of the board if the socket which connects to the car loom is on your left. Mine had the value 6R2 written on them, I expect all MAF's will have the same value resistors, it could be written 6E2 by some manufacturers. Using a small soldering iron somewhere around 30 to 50 watts power and preferably temperature controlled carefully melt the solder on both ends of one resistor and lift it away from the PC board. A pair of fine tweezers may be helpful but don't damage the resistor. You may have to keep heating the ends alternately a few times to get it off (don't force it) unless you have one of the special soldering tools which heats both ends at once.
Don't do both resistors at once as all resistors have some production spread of actual resistance and this has been accurately compensated for at the factory (you'll see some tubular resistors on stand-off legs which have been chosen for exact calibration) so you don't want to mix them up.
Once it is removed, use the iron and some fresh electronics grade resin cored solder (preferably 60/40 leaded not lead-free as it cracks too easily) to reflow and clean the lands on the PCB where the resistor attaches. Then do likewise with the terminations on the actual resistor. When fully satisfied that all is clean and good to go, solder one end of the resistor back onto the PCB, leaving the resistor sticking up at a small angle so the other end is clear of its land on the board (if you're not too familiar with these things, they're not directional so can face either way). Now take a piece of scrap automotive electrical wire and strip it down to get some fairly thin single strands of copper and cut a strand about 5 or 6 mm long. Solder one end of this flat to the free land on the PCB and then curve the other end around to meet the resistor end flat-on. Now solder it. This provides a bit of 'give' by movement of the wire for the expansion and contraction so should help to prevent the problem from happening again. (I didn't do this when I fixed mine, I just soldered them back as they had been on the board and thought of this idea later so I will do it sometime).
Repeat for the second resistor.
Don't be tempted to just reflow the solder on the resistors in place: you won't get to the solder under them and it will be a very short term fix if it fixes it at all.
When you're happy that everything is connected correctly (it's possibly worth gently pulling on the curved wires to be sure they're really soldered properly) then refit the MAF to the car and test with the car stationary and tapping on the circuit board (not too hard that you break something though) with something insulating like a plastic pen to see that there's no change in engine operation at higher revs due to some other problem. All going well, fit the shield in place and go for a test drive (it won't pop out if you got it out without bending the metal fingers). If it passes the drive test then refit the plastic cover, putting some silicone sealant on if you wish (that may also hold it OK if you broke some tabs!) but use neutral cure silicone not RTV as RTV has an acid solvent which will corrode electronics.
I hope this helps you, and feel free to have it set somewhere else on this board where it can be readily found.
The MAF is easy to repair if you have any soldering skills. I posted a full description of what fails and how to fix it somewhere here but now can't find it, so if you don't mind the read, here it is again in all its glory:
The hardest part of the repair is getting the top lid off without breaking any of the four little plastic tabs which hold it on. In my case it seemed that there could have been a bit of silicone sealant also keeping the lid on which made it harder so I ended up breaking two of the tabs and having to improvise some clips to take their place. So, remove the MAF from the car and if you like, dismantle it from the plastic airway parts to make it easier to handle. Then remove the lid. Under the lid you'll see a metal shield which is held in place by springy tabs. Just ease the shield out, try not to bend it so it will fit back nicely later.
NOTE: the purpose of the shield is to prevent any radio frequency signals nearby from affecting the operation of the MAF. Test at idle with it removed but DO NOT take the car onto the road without it in place: I do not accept responsibility for any crashes caused by sudden changes to the car's operation while driving due to some nearby radio emission e.g. your cellphone!!!!!
Our MAF works by the incoming air which has had turbulence caused by the special inlet and shaping passing over two heated wires causing their temperature to vary. As with most metals the electrical resistance of these wires is temperature dependent so we have a variation of resistance in response to the airflow. To allow this resistance change to be measured accurately the current which flows through the wires to heat them must be carefully regulated. This is accomplished by having a precision resistor in series with each wire, the voltage which appears across this resistor is compared with a reference voltage in some simple electronics and the resulting error signal is used as feedback to the current control transistors. This means that when the car is switched on these resistors also heat slightly due to the current flowing through them, and when the car is switched off again they cool. As with most things they expand and contract slightly with this heating and cooling. They are soldered to copper tracks on a fibreglass based circuit board which has a different amount of thermal variation and this causes stress to be applied to the solder joints at each end of these resistors, eventually causing the solder to crystallize and become an intermittent connection which is very susceptible to vibration. In my case the car would often idle but when any throttle was applied the vibration caused the contact to make and break rapidly giving extra pulses from the MAF to the ECU. The ECU saw this as heaps more airflow and ramped up the fuel to the point where the mixture would not ignite stopping the engine and producing rather a lot of black smoke occasionally.
The repair:
I'm assuming you or someone you'll get to do this for you is confident with soldering of electronic components:
Locate the two larger resistors which are flat rectangular items on the circuit board towards the top right of the board if the socket which connects to the car loom is on your left. Mine had the value 6R2 written on them, I expect all MAF's will have the same value resistors, it could be written 6E2 by some manufacturers. Using a small soldering iron somewhere around 30 to 50 watts power and preferably temperature controlled carefully melt the solder on both ends of one resistor and lift it away from the PC board. A pair of fine tweezers may be helpful but don't damage the resistor. You may have to keep heating the ends alternately a few times to get it off (don't force it) unless you have one of the special soldering tools which heats both ends at once.
Don't do both resistors at once as all resistors have some production spread of actual resistance and this has been accurately compensated for at the factory (you'll see some tubular resistors on stand-off legs which have been chosen for exact calibration) so you don't want to mix them up.
Once it is removed, use the iron and some fresh electronics grade resin cored solder (preferably 60/40 leaded not lead-free as it cracks too easily) to reflow and clean the lands on the PCB where the resistor attaches. Then do likewise with the terminations on the actual resistor. When fully satisfied that all is clean and good to go, solder one end of the resistor back onto the PCB, leaving the resistor sticking up at a small angle so the other end is clear of its land on the board (if you're not too familiar with these things, they're not directional so can face either way). Now take a piece of scrap automotive electrical wire and strip it down to get some fairly thin single strands of copper and cut a strand about 5 or 6 mm long. Solder one end of this flat to the free land on the PCB and then curve the other end around to meet the resistor end flat-on. Now solder it. This provides a bit of 'give' by movement of the wire for the expansion and contraction so should help to prevent the problem from happening again. (I didn't do this when I fixed mine, I just soldered them back as they had been on the board and thought of this idea later so I will do it sometime).
Repeat for the second resistor.
Don't be tempted to just reflow the solder on the resistors in place: you won't get to the solder under them and it will be a very short term fix if it fixes it at all.
When you're happy that everything is connected correctly (it's possibly worth gently pulling on the curved wires to be sure they're really soldered properly) then refit the MAF to the car and test with the car stationary and tapping on the circuit board (not too hard that you break something though) with something insulating like a plastic pen to see that there's no change in engine operation at higher revs due to some other problem. All going well, fit the shield in place and go for a test drive (it won't pop out if you got it out without bending the metal fingers). If it passes the drive test then refit the plastic cover, putting some silicone sealant on if you wish (that may also hold it OK if you broke some tabs!) but use neutral cure silicone not RTV as RTV has an acid solvent which will corrode electronics.
I hope this helps you, and feel free to have it set somewhere else on this board where it can be readily found.
- Thread starter
- #11
Very informative! I'll give that a shot next month when my insurance is up. That way if I royally screw it I can get another MAF ordered and not be freaking out about waiting for shipping to Canada
Tony_T
Leaving Skid Marks
It's really easy so you shouldn't screw it up! Are you up to doing it yourself, or know someone who is handy with fine soldering?
I'm an electronics / radio comms tech so when mine played up I decided to reverse engineer it and find out what failed. I was very pleasantly surprised when I discovered the fault and noted that I have come across the same problem in some radio transmitter modules I see for repair because they heat up when transmitting and cool again between transmissions which can be many times per hour.
I'm an electronics / radio comms tech so when mine played up I decided to reverse engineer it and find out what failed. I was very pleasantly surprised when I discovered the fault and noted that I have come across the same problem in some radio transmitter modules I see for repair because they heat up when transmitting and cool again between transmissions which can be many times per hour.
- Thread starter
- #13
I'll be doing the work myself. I don't know these cars extensively yet but so far no one has worked on any of my cars but me. Now that I'm not at a shop I'll have to have my tires installed by someone which sucks, but as long as they don't damage my wheels I'm good 
When I bought this car I immediately had to do lower control arms, a hub, and a timing belt. I feel like every vehicle is a chance to learn.
When I bought this car I immediately had to do lower control arms, a hub, and a timing belt. I feel like every vehicle is a chance to learn.
Tony_T
Leaving Skid Marks
Let me know how you go. I'll be interested if you can get the lid off without any of those four little plastic tabs breaking as they're so brittle now due to the heat and age.
- Thread starter
- #15
MAF finally kicked the bucket for good. Haven't pulled it apart yet but I'm looking for a replacement so I have a spare.
Do any MAF's from any other Mitsu's work or are they specific to these vehicles?
I have a bunch of MAF's at my shop that basically look identical off EVO's and other Mitsu's but the P/N's are different.
Do any MAF's from any other Mitsu's work or are they specific to these vehicles?
I have a bunch of MAF's at my shop that basically look identical off EVO's and other Mitsu's but the P/N's are different.
Mr Smurfington
Idling at the Lights
way way into the future here. I was curious if an Evo MAF was able to get you running while sourcing/repairing the VR4 MAF. My 97 is experiencing the same exact issue you are describing here. I've not been successful through my searches of a solid answer on whether or not the Evo MAF is a sufficient stopgap.
