Adventure Driven Talk

Tech Questions and How-To Articles => Mitsubishi Related => Gen 2 Montero => Topic started by: AK-Clay on April 16, 2018, 06:45:49 PM

Title: Engine code 41 (main throttle solenoid valve system)
Post by: AK-Clay on April 16, 2018, 06:45:49 PM
Alright so I am low on time, I have this 1995 Montero 3.0 24L that I have been trying to get right for our eldest boy, and I am now in a pinch.
I was on my way to get the emissions tested and all excited, but yet nervous... While almost there I noticed the truck was running rough almost as if it was misfiring, or had a dead cylinder and the check engine light came on...

Turned around got it home and started pulling plug wires from the coil packs and noticed that all but #1 cylinder made a change in RPMs...
There was spark from the coil pack, plugged the plug wire back in and got spark from the end of that, swapped out the spark plug (which I noticed needed to be replaced anyway and felt hopeful that was the issue) still no better. Pulled the spark plug out and connected the plug wire to it and was getting spark, so that lead me to think there was no fuel getting into the cylinder...

However in pulling the codes I originally pulled a ton, but cleared them as they were probably false positives from my earlier troubleshooting. But the one that remained was code 41 (main throttle solenoid valve system)

I have never dealt with this one, and looking it up on the googles it seems that it is one of those little solenoids that no one pays attention to mounted on the fender or on the side of the battery tray.

Anyone had to deal with code 41? Code 41 seemed more like an emissions thing than am engine issue. Maybe I miss diagnosed the dead cylinder?
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: AK-Clay on April 16, 2018, 07:12:00 PM
Update.. Just swapped out the Idle Speed motor from my 98 blister fender... started, idles good, and no check engine light.
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Crumb on April 16, 2018, 07:13:26 PM
 SOLID!
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Crumb on April 16, 2018, 07:14:03 PM
 Now go drive and get those readiness codes. Also fix your '98 now.
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: AK-Clay on April 16, 2018, 08:16:07 PM
Never mind, once you put it in gear it throws code 41 again.
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: IncorpoRatedX on April 16, 2018, 08:50:30 PM
I've never experience such a code. I've got nothin, googled around some and came up with more for diesel trucks than anything.
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Shovel on April 16, 2018, 08:58:38 PM
I googled.. (yeah I know anyone can google...)   Mitsubishi code 41  and came up with a lot of results from pre-OBD eclipse guys pointing at injectors. 

Since you said you tried pulling spark from one cylinder at a time and #1 made no change when you  pulled it,  maybe check the connector for the #1 injector?    and check the dc resistance of that injector too if you can?   FSM says 13-16 ohms.

All I got for now.
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: AK-Clay on April 16, 2018, 09:35:58 PM
Yea I just pulled the fuel rail.
That was my first thought was no fuel to the cylinder cause I was getting spark all the way to the spark plug. But I decided to pull codes in hopes of finding a more direct answer.

That really lead no where and yea I found the same stuff; diesel and a one that supported my theory. So I was going to swap fuel injectors in from my 98 but the 3.5L is different. I took the #1 injector off the rail and jumped the pins w/ 12 volts and got it to click off and on. so that portion works I guess.

Maybe I can just clean them... I just hate the idea of putting something that is known to be bad back in with the hopes of it working again... But maybe I'll get lucky and it was just stuck and me beating it upside down dislodged some garbage lol
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Shovel on April 16, 2018, 09:38:21 PM



Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Shovel on April 16, 2018, 09:40:37 PM


I guess even if these don't help you they may help in the future if someone else is searching. 
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Shovel on April 16, 2018, 09:46:48 PM
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Shovel on April 16, 2018, 09:50:48 PM
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: AK-Clay on April 16, 2018, 10:50:22 PM
I'll have to look these over tomorrow.

I just got done running mineral spirits through 3 of the injectors one being the one I think was the issue and it does work now out of the truck. So tomorrow I'll finish cleaning the injectors and put it back together and see what happens. If the problem persists then I know its an electrical issue somewhere.

Thanks for the help guys!
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: AK-Clay on April 17, 2018, 07:25:28 PM
Well now it seems all 6 cylinders are firing.

But now there is a lot of fuel coming from the exhaust flange.
Anyone know what would cause an excessive amount of fuel to be delivered to the cylinders?
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: Shovel on April 17, 2018, 08:01:55 PM
Well now it seems all 6 cylinders are firing.

But now there is a lot of fuel coming from the exhaust flange.
Anyone know what would cause an excessive amount of fuel to be delivered to the cylinders?

Injectors can leak (like between firing) if they're all crusty,  or it could still be in open loop mode from when it thought it was running lean and hasn't adjusted back yet - but that would be a little bit rich not like huge volumes of fuel coming out unburned from the exhaust.   

Disconnect the battery and try to get it in closed loop again? 
Title: Re: Engine code 41 (main throttle solenoid valve system)
Post by: AK-Clay on April 17, 2018, 08:10:23 PM
I shall try!