Truck jerks and lunges violently no rpm or speed change?? Mk2 v6 mm

[Chyrio]

my truck would kind of lunge when the ecm went bad but i have a 4cylinder. try checking the ecm and post some picks of the inside. sometimes the caps inside go bad.

I already checked and replaced the caps with better newer ones. The ones on there where not bad but I replaced them anyway.

[Jeff V.]

are your real brakes locking up? i dont know if you can do this but remove the rear drums and put the tires on and take it for a quick spin and see what it does.

I hope nobody ever, ever does this. If the pistons don't pop out of the rear wheel cylinders completely, you'll still have a massive loss of brake pressure and thus, inoperative front brakes. Please do not ever suggest this again.

[Jeff V.]

This PDF is a little ghetto, but it's the best I could do with the software I had. This is the 92-95 MFI wiring for both the 2.4L and 3.0L.

http://xtreme3s.net/Max50/92-95%20Max50%20MFI.pdf

The 3.0 MAF is on the bottom right of the last page.

The pinout for the sensor is:

1 - GY - 5v input from ECU
2 - O - Barometric signal to ECU
3 - LY - Airflow signal to ECU
4 - R - 12v from MFI relay
5 - B - Sensor ground
6 - RL - Intake air temp signal to ECU
7 - RW - MAF sensor reset signal
8 - NC - No connection

GY = Green/yellow
O = Orange
LY = Blue/yellow
R = Red
B = Black
RL = Red/blue
RW = Red/white
NC = No connection


Fortunately the 91+ 3.0 trucks used the same MAF as the 91-93 Diamante, the 91-94 3.0 Montero, and NA 91-93 3000GT (both DOHC and SOHC). MD151055 is a direct swap. The silver label on top of the MAF will just say '055'. Later MAFs will work for coarse testing, but the sensor calibrations are different and they're not a 'correct' match to the ECU.

[finalfighter]

i cant believe i suggested that. wasnt exactly sober when i wrote that either. thanks jeff V for catching that. my deepest apology for recommending that to you. it truly was a dumb ass suggestion. sorry again.

[Chyrio]

This PDF is a little ghetto, but it's the best I could do with the software I had. This is the 92-95 MFI wiring for both the 2.4L and 3.0L.

http://xtreme3s.net/Max50/92-95%20Max50%20MFI.pdf

The 3.0 MAF is on the bottom right of the last page.

The pinout for the sensor is:

1 - GY - 5v input from ECU
2 - O - Barometric signal to ECU
3 - LY - Airflow signal to ECU
4 - R - 12v from MFI relay
5 - B - Sensor ground
6 - RL - Intake air temp signal to ECU
7 - RW - MAF sensor reset signal
8 - NC - No connection

GY = Green/yellow
O = Orange
LY = Blue/yellow
R = Red
B = Black
RL = Red/blue
RW = Red/white
NC = No connection


Fortunately the 91+ 3.0 trucks used the same MAF as the 91-93 Diamante, the 91-94 3.0 Montero, and NA 91-93 3000GT (both DOHC and SOHC). MD151055 is a direct swap. The silver label on top of the MAF will just say '055'. Later MAFs will work for coarse testing, but the sensor calibrations are different and they're not a 'correct' match to the ECU.

So I'm assuming pins 4 and 5 should not ohm out? Cause they do ha ha

[Jeff V.]

5 should have continuity to ground. I think 4 will show continuity to ground with the ignition switched off.

Put a multimeter on 4 and 5, then turn the ignition on. You should see battery voltage.

Hell, just unplug the MAF entirely and try to drive it. It'll be slugish because it'll be in limp mode, but it should still drive.

That reminds me...it's probably worth checking your throttle position sensor too. There's procedures all over the internet for that.

[Chyrio]

Found the issue. no idea how this happened but after we replaced it. problem vanished. this is the pinion bearing.

[Chyrio]

Hell, just unplug the MAF entirely and try to drive it. It'll be slugish because it'll be in limp mode, but it should still drive.

Today after i replace the pinion bearing i drove it around with no MAF and it honestly didnt run any different than it has been. plenty of power doesnt feel like its in limp mode it just runs rich and idles higher than normal.

[geezer101]

Hell dude, I've never seen a bearing in that condition before. It would be interesting to know what the actual cause of the damage was.

[Chyrio]

Hell dude, I've never seen a bearing in that condition before. It would be interesting to know what the actual cause of the damage was.

Guy at Auto Zone says it had to of been done during installation.

[geezer101]

Guy at Auto Zone says it had to of been done during installation.

Why do some people have poseable thumbs...