Trying to get an old warhorse running again

[Rake]

Alternate title: Adopting a new problem child.

 

Greetings everyone. I'm probably crazy, because I'm jumping into fixing/restoring a Comanche that's been sitting for about 3 years with no care. I've had a 97 Cherokee before with the straight-6 and loved that truck, so this is something I'm looking forward too. Just to state upfront, I'm going into this with a very minimum of automotive knowledge and few tools, and just trying to learn as I go. I'm a gunsmith by trade and already figured out I'm way better at basic diagnosis on those than vehicles. I hate seeing things wasting away, automotive is something I want to learn, and I've presently got a lot of free time so I thought why not?

 

Vehicle details are it's a 1987 Comanche, 4x4, base model I think, with the Straight 6 4.0 and an automatic transmission. I don't own it yet, though I'm almost certainly going to buy it. The owner is a very good friend of mine and has given me carte blanche to try to get it running, in his words 'It's not doing me a damn bit of good just sitting there'. It was running when parked, but he said it had an oil leak, was coming up on a brake job, and most importantly he had a new car that was under warranty so he decided just to park it.

 

When I first went into it the battery was dead as a slow possum on a busy highway, so I swapped it out for a second-hand battery. Smaller than it needs, but it works well enough to turn the starter and let me trace the electrical. The starter cranks, the ignition coil throws a spark, but it doesn't start. I think I figured that out though (I hope). The gauge registers a full tank, and silly me didn't physically confirm until I decided to check the fuel rail and it was bone dry, along with the tank. On that part of it I'm going to add some new fuel, and see if the pump/sender assembly works. It looks like the relays might have had water damage, there's some moisture and corrosion around them so I'm guessing they might need to be changed. I couldn't find any sort of a relay schematic and I don't have access to a service manual, so if anyone could tell me how to tell which from which, and hopefully test them, I would really appreciate it.

 

It's also pretty low on oil, and the oil's been sitting along with the rest of the vehicle. I know it needs changed but should I get it to run and then change it so that whatever detritus hiding in there may be loosened up, or change the oil and filter before I even try to turn it over any more?

 

I also noticed an air line was busted, dry rot maybe. I don't know the technical terms, but it was a large line running between the air filter and the top of the motor. I'll try to get a picture up tomorrow.

 

It's got what I believe is called the closed cooling system (Degas system?), which I am not remotely familiar with. What do I need to know about that?

 

A more general question, but the tires are of course flat from sitting, but they aren't cracked from excessive dry rot. I'm going to try and see if they'll keep air because they were really nice tires when it was parked. Are there any tricks I can use to increase my chances or just cross my fingers?

 

Anything else at all that might help and any other resources I can find to learn more I would love to have. I've read through a few threads on here and I'd just love to have the advice of people with much greater subject knowledge than I.

[aaronbtxnc]

First thing I'd do is get it in your name unless you're willing to do all this work for nothing on your friends truck.

[tugalo]

First thing i would do before turning over the engine is remove the plugs and squirt some oil down in the cylinders. Leave the plugs out and spin it over to lube the cylinders.

 

Schematics and troubleshooting manuals are available on this forum.  They are mostly for an 88, but should work pretty well for your truck.  As you know, if you get it running, these old Renix trucks are pretty much bullet proof........  good luck.

[Green Mesa XJ]

Yeah make sure you're working on your jeep otherwise you're just being generous with your time and money. If the body is good and the frame isn't rusted I'd buy it. But then i would be prepared to throw new motor and electronics in it if I had to and I have most of the parts stored for the some day I need them scenario. So I guess but it low enough you can see putting money into it to fix it.

 

On starting vehicles that have sat for years I like to put fresh oil and filter, pull the relay (or whatever) supplies power to the fuel and crank it to get the oil pressure up. It's a trick for working on a car with a oil fed turbo. We'd crank until we'd see the oil pressure gauge show movement.

 

I've started engines that sat for a long time without priming the oil too and never had a problem. But now I like to try to prime the oil at least a little.

 

Fuel system may be your biggest problem, old gas can varnish and clog. Three years isn't good but might not be as bad as I'm thinking.

 

On reallly old vehicles that have sat for a long time, pulling the tank and replacing it, lines and filters usually works out the best. On this I'd check what is in the tank by siphoning out some gas,

Replace the filter, not sure on the MJ, but on the xj with the filter off I could power the pump and put the fuel line from the tank into a bucket and pump it out.

If you're lucky the gas was low and since evaporated out and you've got an empty tank too add fresh gas and fuel cleaners to.

 

If it were me I'd probably try to work in the engine first, pulling the power to the fuel pump. See if the engine will run (various way to do this without the fuel pump and injectors firing)

 

 

Then get the fuel system up to par when you know the engine will run.

But you're going to have to look for rot and rodent damage. You'll also need to change the fluids for just about everything.

 

Good news is the transmission is a AW4 and was used 87-01 with various changes through the years, so it's pretty stout. Bad news is it's a 30 year old jeep and even if some parts were ok when parked it might not be ok now.

 

You might not be so bad off because it's only sat 3 years . Take some pictures or videos, I'm sure some other people here will have better ideas on what to do getting it running.

 

 

 

 

 

 

 

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[ParadiseMJ]

My truck sat in a barn with the bed off, tank out, interior stripped and wiring a mess for 8 years.  Took me 5 gallons of fresh gas, 6 qts of oil, a weekend, a battery, and a CPS.  Fired up Sunday afternoon.  3 years is really not much with a 4.0L unless it was neglected before that. 

 

 Start with tugalos idea and then go here: www.cruiser54.com

[Rake]

Thanks for all the tips, especially the part about oiling the pistons. I'll be heading over to work on it tomorrow, definitely picking up a T-Handle now for the plugs, I'll clean them up, check the gap and spray some oil down. Figuring that, changing the oil and filter and getting some new gas in the tank then going from there. I'll definitely take some pictures of the engine compartment too.

 

I appreciate the concern over working on a vehicle I don't own yet, but I'm not planning on sinking too much into it before the title changes hands, and if that and some time that I wouldn't have spent doing anything otherwise productive is what it takes to show that someone I trust isn't trustworthy, well that's a lot cheaper than some bills I've had to pay in that respect in the past.

[fiatslug87]

The '88 electrical manual can be downloaded here: http://comancheclub.com/topic/12083-electrical-manual/?hl=electrical+manual

[Green Mesa XJ]

Being what this vehicle is if the fuel pump works it may just fire up.

 

 

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[omega_rugal]

don`t try to star it until you clean up everything, change the oil, prime the oil pump and recheck all fluids, including brakes, you don`t know how many people fire them up, take them for a ride and then realize ther have no brakes...

[Jtrux]

I picked up my Comanche after it sat for 15 years out in the open in a field.  Been daily driving it for a little over a year now but it's going down for some upgrades as we speak.

 

I ended up having to install a whole new fuel system (tank, sending unit, pump, filter, throttle body rebuild) and a few other small things but that was the big one.

 

Runs good after that and I have about 6k miles on it since I picked it up.