My wifes Montero Sport has a periodic miss on the 3/6 coil pack. It is a 3.5L with 149,000 miles. I took it to the parts store and the code reader could not connect to read the code. I checked fuses but to no avail, no connection could be established. I was gonna try a new coil pack and when I went to put it on, decided to crank her up and see if it was still missing. Guess what no miss. Took the coil pack back and went to leave the parts store and the miss was back.. Always on 3/6 pack.

I bought a timing belt because it has never been changed, spark plugs, cam seals, crank seal, water pump, valve cover gaskets, intake gaskets, just to do a much overdue tune up.

I have it tore down to the timing belt currently and the belt is tight everywhere except on the water pump. I took the belt off without loosening the tensioner. Would this cause the periodic miss? The tensioner also is oriented 180deg from how the book picture has it. My 2 small holes are on the bottom. Isnt that upside down?

Also, when I went to put in the Timken oil seals on the cams, they would easily push in by hand. After sitting a bit, they are hard to push any further so do you think they are good or should I put some sealant on them?

Anyway, I need some expert help on whether or not the timing belt will resolve my problem? What else should I look for while I have it tore down?

I tried the cruise control code read trick and got a 11 for the code. At least 1 long flash and 1 short flash. I think its a 11. The book said something about a vacuum leak but the "generic" code reader book said camshaft sensor fault. Which code is correct?

Whooo. Sorry for the long story. I need some help. We dont have a Mitsubishi dealer anywhere near here so I hope you all can help. Nothing like the help you can get on topic specific forums.

Thanks,

Dusty

 

Yes, that could definitely cause a periodic miss!

Good thing you caught it in time too.

 

I just finished with the install of all of my components and when I fired her up, it had a little pecking of the lifters but ran great. Took it down the road and had more power than ever. Came back home from about a mile trip to check the fluids and she started missing AGAIN. 3/6 coil pack no fire at all.

Im at a loss. I dont know where to look now.

Any help?

 

All I can think of from here is an ECU malfunction.

 

Can you tell if the coil is getting power, or is the trouble in the coil itself? Could you swap out the coil and see if it happens on another bank?

 

the coil pack is fine. after the vehicle warms up, it stop getting fire to that one pack. i tested my ignition control module and its fine. im thinking of trying a ecu if I can find one. MR578044 is the part number.

 

This symptom reminds me a problem I had on an old Audi Fox. It would start fine in the morning but after it warmed up, it wouldn't start again unless you jumped the starter solenoid or simply let it cool off for awhile. After many new parts later, the problem turned out to be a loose electrical connector that ran over the engine. Once it got hot; it shorted out.

Intermittent electrical troubles might well be your ECU, but I'd first look at your wires. You could have an internal fault that would only show up when hot. It's worth a try and certainly cheaper than a new electronic brain.

Either way, let us know what happens.

 

well during the warm up stage you can actually have the coil pack still connected and a plug wire off and see the fire jumping across, but once its stops it does not even have fire to the coil pack anymore. The ignition control module still has connectivity between the post so its loosing signal somewhere. This signal comes directly from the ECU. So that is why I think I need to change it out. I cant think of anything else.

IS there a way to monitor the signal from the ECU like with a multimeter to see if it actually loses signal at that point? Not sure which wires control that coil pack.

Anyone have a wiring diagram? My workshop manual doesnt have diagrams.

 

OK, from the misty past of 1995-era vehicles comes this tidbit of probably useless information:

Between the ECU and the coils is a power transistor. The wires from the ECU to this transistor are WHT, BLK/GRN, WHT & RED/BLU. One of the WHT wires splits to feed the tach and the engine speed detection connector.

Just a thought. There's a BLK ground wire on the power transistor; it might be worth checking that this ground is solid. As far as hooking up some kind of way to monitor the ECU's output, I don't know about that.

You mentioned your output code ~ one long and one short. Way back in 1995 my manual says it's either:

• harness & connectors
• fuel pressure
• injectors
• intake air leaks
• oxygen sensor

None of which would seem to directly bear on your problem. Hope this will help you in some small way.....

Now go out and get a manual with a wiring diagram in it

 

Buying a manual its not worth it to me. As soon as I get it fixed I'm unloading this thing on some other poor soul. Mitsubishi is a terrible brand. I married into this vehicle so its not my choice. We are die hard American motor only. I know most of everything today its not American made but at least their roots are.


Thanks for all the help. Will post when I get it fixed.