1985 CUCV J Code 6.2 Help/Advice

[48cj2a]

Purchased 1985 CUCV M1009 (Blazer) with 48K from my local Police Dept. They procured it from Ft Carson, CO so there is very little rust and it is in really good condtion. They swapped the 6.2 with another they already had in service that was hydrolocked and then rattled real bad.

I have the engine pulled and on a stand, ready to check it out. This engine also was in the 40Ks mileage rage so I would like to at least see if it is something easily repairable before I go to a different motor.

Where should I begin first and what should I be looking out for?

Any help would be greatly appreciated.

http://www.48cj2a.com/images/cucv/cucv.jpg

[Robyn]

These engines are very basic.

Just about the same as a little mouse motor.

Yank the intake, injector lines and such off to get down to the heads.

Leave your fuel injection lines in the pairs that they are assembled in.
Unhook each set from the injectors and then the PUMP.

Mark the sets 1-3 5-7 and so forth.

Make a little map of the back of the IP as this will really hasten aseembly.

There are two lines that can be mixed up so it helps.

The cyls are numbered as any chevy V8 Number one is front on LH side or engine then 3-5-7 and 2-4-6-8 on the RH side.

Get the heads off next.

Be aware that the head bolts are a one time use on these engines.

Also the push rods are directional and the ball end marked with a copper color goes to the rocker.

This can be tough to see but is mandatory to do. (one ball is hard the other is not)

Once the top is off, flip it over and get the pan off.

Just look everything over real well and check for the obvious stuff.

Take pics and post if you have to. We can help you all the way.

Missy.

[48cj2a]

I began the engine tear down today. Got to the point where I was ready to remove the RH head.

Third pushrod from the front on the # 4 cyl was very rusty.

Got the head off and was very surprised to find #6 and # 8 cyls very rusty and #6 definitely had something in it long enough to beat the heck out of the piston. Even had some indication that something might have had threads on it.

Is this economical enough to pursue or should I look for a replacement motor? Can I assume cracked head with the rust?

[48cj2a]

Here is a picture of the damaged piston:

http://48cj2a.com/images/cucv/6.2/62damage.JPG


Before spending any foolish money is there any value in getting a good used piston for this engine?

Where do you look for prone cracking in the heads to determine if keepers or scrap.

Whats a core 48K miles IP worth?

Whats a core 48K 24v starter worth?

Whats the Gen 1 and 2 with 48K miles worth?

Like to recoupe something from these parts if possible.

[48cj2a]

Sunday I took delivery of an 87 CCLB with a replacement Target 6.2 that sounds pretty good.

I plan to pull this motor and attend to any details needed and replace the CUCV 6.2.

Since this is a complete Civy 6.2 my plan was to unbolt and use the stock civy engine harness in the CUCV and eliminate some of the problem electrical issues the CUCV is known for.

Does anyone know of any issues or should this be plug and play?

Also the 87 has a gauge cluster so would like to also swap this into the CUCV and do away with the GEN 1 and 2 lamps as well as the over sized 4wd lamp and take advantage of the guages. Is this also a plug n play or do I need to swap interior (dash) wire harnesses as well.

Any advantages to any of the CUCV engine parts like intake, and other bolts ons that I should swap during the installation?

Also plan to take advantage of the civy battery brackets.

Anything else I may be missing??

[Robyn]

You are on the right track.

Since you will have the engine out and the dash apart anyway, just swap the complete underhood and underdash harnesses.

If you swap all the stuff you will pretty well be plug and play.

The Mil stuff is slightly different so I would not recommend using any of it.

Just swap all the dash wiring, the cluster and such from the donor vehicle.

The fuse block/electrical junction is easy to remove.

There is a single bolt on the firewall side, right in the cneter of the harness plug at the firewall.

Remove that bolt and the whole unit unplugs and comes out.

Then the bolts on the inside can be removed and the harness taken out as a complete setup.

I have done this. Take PICCY's and mark all the plugs and such as to where they all go.

Once you go to reinstall, it will all fall right back into place and go to work.

You will then be free of the 24V systems and all the stuff on the civvy dash will work too.

Have fun

Missy

[48cj2a]

Missy,

Are there benefits from any of the bolt ons like intake, CDR etc from the Mil J code motor.

Also please read my post before my last one asking about wiring and answer anything if you can.

I want to locate the castings on this replacement motor to see what block I have, can you educate me here as well.

[48cj2a]

Took your advice and pulled the dash harness and cluster out of the donor truck.

Got everything ready to give it a test fire today...hooked the engine plug to CUCV harness and got dash lights and buzzer but not iginition.

I pulled it loose and went and grabbed the donor harness, a tilt column I got at a pick n pull, layed it across the brush guard and drivers tire, ran a temp ground, hooked up the cluster and harness for what I think is the glow plug circuit plug for the dash. Engine is turning over now, but not hearing the glow plug relay clicking, and of course not starting. The glow plug light (I think) did cycle and another lamp is staying on.

Any ideas?

[Robyn]

Hmmmmm

Grounds and connections are most likely the culprit as to why the electrical stuff is not quite right.

Install the wiring in the truck and pay close attention to detail on the plugs, grounds and such

The under dash harness has a "Ground Buss" over on the LH side of the "Under dash" right behind the LH AC vent

There is a mulitple plug Buss that several grounds all connect to.

Be sure the Buss is grounded good to the sheet metal with a star washer between the Buss and the body and another star washer between the screw and the buss.

Dielectric grease is a good insurance policy on any of the plugs.

The Military intakes are generally a good item (No EGR)

The engine needs a CDR but either the Civvy version or the Mil ones are fine.
J code stuff is going to be the best parts. There were a few different J code intakes made. One style was a dual plane and the other was a single plane.

I have seen both but, consensus seems to be that the single plane is the best choice.

Anything is better than the Plugged up EGR soot stoker that the C engines had.

The engine block numbers are on the RH rear of the engine block right behind the head on the ledge just ahead of the bellhousing.

The last 3 digits tell us what we need to know.

On the block casting down on the vertical face right by the starter (IIRC) will be a series of numbers/letters, this is the Julian date. (when the thing was cast)


Hope this helps.

Missy

[DieselCrawler]

Great advice I compleatly agree with, Missy...

I have converted my CUCV 1028 truck to civilian wiring...

Complete conversion, dash harnes, motor harness, headlight harness... Changed the starter to a 12v version, with a lifetime warrentee (Replaced at least twice now) and modified the glow plug system. I replaced all glow plugs, I think I used AC-60G (I don't remember, it was the better ones if IRCC, I used some Kennedy's in my blazer) and went with manual glow plugs, due to the dash harness being a gasser harness, and wanting total control of the plugs. Used the factory GP relay, just put a push button on the bottom edge of the dash, it's easy to hit when starting the truck when needed. I also put a 4 headlight core support on, liked the dual headlights better.

All the parts are like legos I played with as a kid, take 'em apart, and put 'em back together. From the 'B' pillers forward, the trucks, blazers, and suburbans are all the same sheet metal, so everything can interchange. I recomend using the complete harness from the donar vehicle, so it's a 'system', less chance of difrent years and diffrent options interfering... a '82 motor harnes might fit into a '86 cab harnes/firewall mount, but the wires might be in a diffrent slot, and nothing will work right. I had to mix mine, and it took HOURS with a volt meter on the garage floor sorting out which harnes would work the best, with the least modifications...

I also ditched the factory Oil Pres, Amp, and Temp gauges, and added boost and EGT while I was there... Due to time constraints, I did a hack job on the dash cover, but have plans to re-do the install neatly someday...

Good luck getting your parts back to one truck, in running condition!!!

[48cj2a]

Its been extremely cold and we've had our fair share of snow but we got a little reprieve this weekend with heavy rain to melt the snow and ice and a couple 40 degree days.

Still too cold to play with swapping in the dash harness so I hooked it all back up again outside the vehicle.

Tilt column and dash harness stretched across the brush guard and driver front tire (frt clip pulled). Dash 6 point ground terminal grounded good to chassis and battery (only has one connection to harness, also grounded 1 cluster wire with an eyelet terminal and the gauges are working during crank. I have good ignition turning over and I think I got the fuel system bled of air now.

It does not want to fire and I've discovered the larger terminal on the Alt and the GP replay is not constant hot. Pulled the GP weather pack and terminal 3 is hot with ign.

Why would I not have a constant hot when these two points (alt and GP relay) get their connection straight from the battery?

I ran a wire from the GP relay hot terminal up to the firewall terminal but I'm not getting GPs side power.

Is there a easy way to check the GP relay. This came out of a running vehicle so I would have assumed is was good.