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New Member Bringing a '91 Monty Back to Life

Posted By: Boilermaker4

New Member Bringing a '91 Monty Back to Life - 12/27/19 09:23 PM

Hi everyone!

New user here. I purchased a ’91 Montero (Gen 1) on the spur of the moment a few years ago. I bought her for pennies, but she wasn’t running. I was aware that the timing belt was broke, but not much else. I, quite literally, had no clue what I was getting into. I’ve never really done major auto repair, but I have overhauled plane engines so I have some translatable experience. After parking her for the last two years, I’ve finally decided to dig in during the long, cold winter months up here in Northern MN. Note: this vehicle comes from Georgia and is virtually rust-free.

Vehicle info:
1991 Mitsubishi Montero LS, LWB
3.0L V6, 12 valve, SOHC, 6G72
190k miles

I have been working towards timing belt and water pump replacement over the last few nights (following Haynes manual). Some of the parts had to be removed due to damage. I have removed the following (order of removal may not be exact):
[*]Air intake, cleaner cover, filter
[*]Battery (has not been installed since purchase)
[*]Spark plug wires & plugs
[*]Distributor cap & rotor
[*]Splash pans
[*]Radiator shrouds & radiator
[*]Cooling fan, clutch, & pulley
[*]Drive belts
[*]A/C compressor & bracket (without removing lines)
[*]P/S pump (without removing lines)
[*]Timing belt covers
[*]Water pump (both halves)
[*]Crankshaft bolt & washer
[*]Harmonic balancer, crankshaft flange, crankshaft sprocket, & front crankshaft seal

I am now at the point that I am ready to begin installing the new parts. Pretty much everything mentioned above is being replaced with new parts except for the covers, shrouds, pans…I also intend to replace all fluids in the vehicle. Let's be honest, I don't think a full engine overhaul is out of the question. I'll just be happy if I can get it running for the first time since I've owned it.
So far I’ve learned a lot and have used the manual and this forum to resolve several issues. Before I begin reassembly, there are two issues that I’d like to resolve that I have not been able to find answers to.

1) Vacuum line attached to the bottom of the canister is broken and I don’t know where it is supposed to connect to and what this affects. Conveniently, this is the one vacuum line not fully depicted in the Haynes manual.

2) Ground wire attached to lower LH frame (looks like it may have originally connected to A/C compressor bracket) was found disconnected. I cannot locate where this should properly attach to in the manual.

Here's an image showing these issues:

Here's an album with some other pictures of the Montero.

Thanks for taking the time to read this post. Any assistance provided would be greatly appreciated. Also open to any comments, recommendations, or criticism you may have.

As the greenhorn that I am, any insight is welcomed.

Posted By: chadzeilenga

Re: New Member Bringing a '91 Monty Back to Life - 12/27/19 10:12 PM

Welcome to the forum and glad to see you are keeping another GEN1 on the road. I recently went through the same process when I replaced the motor in my 89 LWB 3.0L. These forums, especially the archives are an excellent source of information. Be sure to check out www.mitsubishilinks.com for access to the full GEN1 Service Manuals which are much more detailed than the Haynes (plus you can reprint them often...)

To answer your questions:
1 - I don't believe that the vacuum line at the bottom of the canister attaches to anything. I believe it is a drain, but I will check when I leave work tonight. From what I recall, there is only (1) hose that crosses over from the inner fender to the intake and that connects to the metal lines on the side of the upper intake.
2 - I believe that the ground wire you are referencing attaches to the block at the mount for the AC compressor.

Be sure to replace the crank bolt and washer with the updated one from dealer. They were problematic.

I've been working through my GEN1 as it is my daily driver. I still have some work to do on the suspension and driveline, but it is getting there slowly. I should get a Google Drive setup so I can document & share pictures easier.
Posted By: Boilermaker4

Re: New Member Bringing a '91 Monty Back to Life - 12/27/19 11:04 PM

Hi Chad,

Thanks for your response!

I've read through a good chunk of the archives so far, and pretty much every article that shows up when searching crank or timing. There is a ton of good info indeed!! Also, I've been taking advantage of www.mitsubishilinks.com. I appreciate the recommendations. Reading through these materials really helped me familiarize myself before I started and continues to do so.

The hardest part SO FAR has been tracking down certain replacement parts that can't be found on RockAuto or mitsu warehouses (e.g. A/C compressor bracket which had been worn through by the pulley...it looked like a lot of driving had taken place after the tension setting bolt had fallen out). Granted, I haven't even begun reassembly...

Thanks for your answers to my questions. If you do get a chance to take a look at the vac line I really would appreciate it!

As for the crank bolt and washer...these are two of the very few parts that I ordered from the dealership since I stumbled across a related Service Bulletin on mitsu-links and wanted to make sure I got exactly what I needed.

Slowly but surely, so it goes. Good luck with yours!

Also, I highly recommend google drive due to it's simplicity and support for google docs, however, as with any free-of-charge cloud-based storage, you should pretty much expect that somewhere in the fine print you're giving google (or other host) full access to anything uploaded.
Posted By: chadzeilenga

Re: New Member Bringing a '91 Monty Back to Life - 12/27/19 11:07 PM

I may have an AC bracket if you need one
Posted By: Boilermaker4

Re: New Member Bringing a '91 Monty Back to Life - 12/27/19 11:17 PM

Thanks for the offer! I managed to find one for sale on eBay at a reasonable cost.

Also, while I'm here, I'm wondering if the thermocouple line that is threaded into the thermostat housing is OEM? It's shown in the picture below. Not sure if it is actually called a thermocouple line, but it's wrapped in a steel spring-like cable and shows a bit of rust. The line runs to a temperature gauge installed in the cab, beneath the steering wheel.


Posted By: chadzeilenga

Re: New Member Bringing a '91 Monty Back to Life - 12/28/19 04:52 PM

That's an interesting temp line, but I'd be willing to guess that it is aftermarket along with the gauge. Check the manual on what reading that specific temperature sensor supports as it may now be disabled to support the new temp gauge.

I checked my 89 and confirmed that the line coming off the vac canister is only a drain and is alongside the overflow tank drain for the radiator.

The ground cable routes from the frame connection to the lower rear bolt on the AC bracket. I'm not 100% that is the factory configuration, but it was on mine when I removed the motor.
Posted By: Boilermaker4

Re: New Member Bringing a '91 Monty Back to Life - 12/28/19 05:57 PM

Thanks Chad! I'll dig a bit deeper into the the function of that temp sensor. Appreciate you taking the time to look at the vac line and ground strap for me. That is the info I was hoping for prior to beginning reassembly.
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