Condensation issues leading to crank/no start in 95 Montero?

[WesternMT1]

Picked up an awesome 95 Montero from a fellow member here this spring (thanks @spacecowboy7777 !) and it's been a great truck. But since the snow and cold has started in Montana, I've had intermittent die and/or crank no-start trouble. I was convinced the fuel pump was giving up the ghost, but upon inspection on a 40 degree day, I have a lot of condensation behind the glovebox (pic of part of the sweaty-looking area attached). Guessing when damp this is causing the intermittent issue with some kind of poor connection or creating corrosion somewhere (fuel pump relay?).

Presumably this is snow freeze/thawing in the cabin air intake, as I can't replicate the issue in freezing temps and it starts/runs fine.

Anyone had similar issues or any ideas to mitigate? Silica packets in the glove box? Cover air intake when parked? Truck lives outside so no help from a garage. Thanks in advance!

 

[Salonika]

Crank or cam sensor would be my starting point. Not sure about the condensation, I’ve never noticed that in the years I’ve had my 2.5
Those connections should be immune to a little condensation.

 

[WesternMT1]

Hmm, hadn't considered that. Maybe the condensation is a misdirect?! Thanks for the idea, will investigate!

 

[MummifiedCircuitry]

Your ECU is down near there also, I would remove it, pop the cover off and check for corrosion on the board. Also, try starting the vehicle and lightly wiggle different areas of the engine harness, if there is a short or issue in an area, the vehicle may stumble or stall. If you haven't already, I'd plug a scanner in and check for pending codes.

 

[spacecowboy7777]

Sorry to hear about the trouble! I would think that moisture is condensation forming on the warm side of the cabin intake as cold air comes in. I doubt it is snow getting in there as the intake tract itself follows a convoluted path specifically designed to prevent water/snow intrusion.

Have you tried pulling each connection and making sure each wire connection is tight? (this caused me an intermittent no start issue on a dirt bike a few months ago) Similarly, have you applied any sort of electrical grease that can displace water and prevent corrosion? (This fixed a no start on an old f150 I had years ago) Something like this:

https://www.grainger.com/product/4YPJ9?gucid=N:N:PS:Paid:GGL:CSM-2295:4P7A1P:20501231&gclid=CjwKCAiAh9qdBhAOEiwAvxIok455IJ-xjHFd-PRoTq6U9KIoxqS5uFxL8_GAsVLU4hLl5WiWI0We6BoCZYgQAvD_BwE&gclsrc=aw.ds

 

[plh]

Your ECU is down near there also, I would remove it, pop the cover off and check for corrosion on the board. Also, try starting the vehicle and lightly wiggle different areas of the engine harness, if there is a short or issue in an area, the vehicle may stumble or stall. If you haven't already, I'd plug a scanner in and check for pending codes.

a '95 is pre OBD2 in these, so a standard OBD2 scanner isn't going to work. Old time multi meter with a needle would work, or a MUT.

 

[WesternMT1]

@plh I've heard really conflicting info on the OBD2 situation in these. I know 95 is before the 96 mandate, but I read Mitsubishi started a few years earlier and the port in the truck *appears* to be the 16-pin OBD2. Might trundle over to an Autozone and find out with their scanner!

 

[WesternMT1]

Good call on the grease, a buddy just suggested this too.

At this point have gone through all (reasonably accessible) connections to check solid wire contacts, jiggled, all the things to try to cause the issue, but I can't replicate it on my own. Will continue the chase and see if I can hunt it down. By the time I do it'll be summer again and I won't have to worry about it. Ha!

Sorry to hear about the trouble! I would think that moisture is condensation forming on the warm side of the cabin intake as cold air comes in. I doubt it is snow getting in there as the intake tract itself follows a convoluted path specifically designed to prevent water/snow intrusion.

Have you tried pulling each connection and making sure each wire connection is tight? (this caused me an intermittent no start issue on a dirt bike a few months ago) Similarly, have you applied any sort of electrical grease that can displace water and prevent corrosion? (This fixed a no start on an old f150 I had years ago) Something like this:

https://www.grainger.com/product/4Y...AsVLU4hLl5WiWI0We6BoCZYgQAvD_BwE&gclsrc=aw.ds

 

[djcommie]

@plh I've heard really conflicting info on the OBD2 situation in these. I know 95 is before the 96 mandate, but I read Mitsubishi started a few years earlier and the port in the truck *appears* to be the 16-pin OBD2. Might trundle over to an Autozone and find out with their scanner!

Mitsubishi adopted the connector much earlier than average (the working group ratified it in 1993 I think) but it doesn't have the same pinouts or communications protocols as I've read in a few places as those were decided upon after this ECU model run started.

 

[WesternMT1]

Update: Had it running a couple weeks ago and sitting at idle it died and ... wouldn't restart. No amount of "drying out" (my previous assumption) helped, but definitely no sound from the fuel pump when in "on" position. Towed it to a shop.

Shop ID's the MFI relay as the problem, as the fuel pump was running with 12v applied directly. Relay tested bad once pulled, so that was part of the problem. The bigger concern is that they pulled the ECM to give it a look too and found a burned up bit (pic attached), which they think probably caused the relay to go bad. A remanufactured ECM ain't cheap, but my bigger worry is that it'll just happen again. Any ideas on what to chase to avoid it?

 

[MummifiedCircuitry]

It looks like moisture got into your ecu based on the discoloration of the board itself around the edge. If you fix the issue of moisture getting to the ecu, I don't think you would have an issue blowing MFI relays or frying ecu's again. You also don't need a reman ecu, if you get the exact number printed on the ecu case, you can swap it in without programming, I've done it multiple times before. Try searching ebay with your part# and you'll probably be able to find an ecu for $150+/-

 

[WesternMT1]

Good eye, I didn't even notice the edge of the board but that does look suspicious! Hadn't thought about the ECU reprogramming, and yeah it does seem like there are some units available w/ the exact part #s. Thank you!