'85 CJ7 4cyl Rebuild

Hey all,

I haven't posted on here in a few years since my Jeep died and I just parked
it. Anywho, I've decided to pull the engine and with the help of my dad and
Jeeping buddies, hopefully do my first successful rebuild. With the
condition of the Jeep, it probably isn't worth the time and money but it'll
be a learning experience for me and I'd rather mess up on this P.O.S. and
have a better idea how to fix the next Jeep I buy (which hopefully is
better). My first problem with this Jeep is the fact that there have been
more hands touching this baby than a cheap prostitute. The engine bay is,
needless to say, a mess. There are wires that go nowhere, throw-together
connectors to bypass stuff, and all these hoses and smog controls that are
just plain silly. I'm looking for help from you guys as to how to strip this
thing down to its bare essentials. Keep in mind I want NOTHING extra in
terms of smog controls and stuff as the laws here are very lax.

The background on the Jeep:
'85 CJ7 4cyl 150cid, 5spd, pretty much stock from what I can tell. The back
cylinder has really low compression (the front 3 are around 120 if I
remember correctly and the back one is like 80 however I'd have to do
another test to remember exactly). It's also blowing a lot of blue smoke out
the back so I'm guessing it's burning oil somewhere inside but I haven't
taken the top off yet to see where the problem is.
A quick review of what happened when it died - I was offroading and it just
"died". A Jeep mechanic here managed to get it running but it kept
backfiring. With the help of you guys we ended up replacing the timing chain
and a bunch of misc electrical parts were replaced or tested (electrical
coil, plugs, plug wires, fuel filter, etc) as well as bypassing the ignition
module, and then it was tuned (a very half-ass job). Now it at least runs.
I'm wondering if all that backfiring didn't damage the cylinder?

Anyways, like I said - once the engine is out and down to the bare
essentials, my dad can walk me through a rebuild. However, he has no idea
what all the hoses, wires, and extra parts inside are for or if any of it
even needs to be there. We want to get rid of the fuel recovery unit,
solenoid, auto choke, breather system & air filter, pollution controls, etc
if at all possible as well as anything else that doesn't need to be there
just to clean it up and make the job simpler.

Since I'm guessing none of you live in Winnipeg and feel like coming over to
help, I'm wondering if I were to post pictures if you guys would be able to
use them to guide me by either explaining what's in a picture or labelling
it, etc. I have the Haynes manual and the AMC Jeep: Super Shop Manual by
Clymer to assist with naming stuff and finding out where it belongs or how
to remove/install it.

Here's a link to a page with the pictures I've taken so far:
http://members.shaw.ca/thegryffy/

or a zip file with all 14 pictures:
http://members.shaw.ca/thegryffy/jeep/allpics.zip

Thank you to anyone who can help at all or direct me to a place that can.

It is easier to live with most of this stuff, than to try to get rid of it.
'85 was the heyday of smog control "insanity", but some of this stuff, like
"breather system & air filter" makes the engine last more than 10,000 miles,
and some of it, like "ignition module" and "auto choke" make it easier to
start those cold Canadian mornings. I would base my decision on whether to
keep this Jeep or not, on amount of body and frame rust. Is that a bird's
nest in one of the pictures?

I am guessing a broken ring from your description, although it could be a
burnt valve and leaky valve guide seals. You want to take the cylinder head
off, and look at that back cylinder wall. If there is a vertical groove in
it, you can get your thumb nail into, that engine is junk.

Earle

"griffin" > wrote in message
news:1NXlg.64993$iF6.4462@pd7tw2no...
> Hey all,
>
> I haven't posted on here in a few years since my Jeep died and I just
parked
> it. Anywho, I've decided to pull the engine and with the help of my dad
and
> Jeeping buddies, hopefully do my first successful rebuild. With the
> condition of the Jeep, it probably isn't worth the time and money but
it'll
> be a learning experience for me and I'd rather mess up on this P.O.S. and
> have a better idea how to fix the next Jeep I buy (which hopefully is
> better). My first problem with this Jeep is the fact that there have been
> more hands touching this baby than a cheap prostitute. The engine bay is,
> needless to say, a mess. There are wires that go nowhere, throw-together
> connectors to bypass stuff, and all these hoses and smog controls that are
> just plain silly. I'm looking for help from you guys as to how to strip
this
> thing down to its bare essentials. Keep in mind I want NOTHING extra in
> terms of smog controls and stuff as the laws here are very lax.
>
> The background on the Jeep:
> '85 CJ7 4cyl 150cid, 5spd, pretty much stock from what I can tell. The
back
> cylinder has really low compression (the front 3 are around 120 if I
> remember correctly and the back one is like 80 however I'd have to do
> another test to remember exactly). It's also blowing a lot of blue smoke
out
> the back so I'm guessing it's burning oil somewhere inside but I haven't
> taken the top off yet to see where the problem is.
> A quick review of what happened when it died - I was offroading and it
just
> "died". A Jeep mechanic here managed to get it running but it kept
> backfiring. With the help of you guys we ended up replacing the timing
chain
> and a bunch of misc electrical parts were replaced or tested (electrical
> coil, plugs, plug wires, fuel filter, etc) as well as bypassing the
ignition
> module, and then it was tuned (a very half-ass job). Now it at least runs.
> I'm wondering if all that backfiring didn't damage the cylinder?
>
> Anyways, like I said - once the engine is out and down to the bare
> essentials, my dad can walk me through a rebuild. However, he has no idea
> what all the hoses, wires, and extra parts inside are for or if any of it
> even needs to be there. We want to get rid of the fuel recovery unit,
> solenoid, auto choke, breather system & air filter, pollution controls,
etc
> if at all possible as well as anything else that doesn't need to be there
> just to clean it up and make the job simpler.
>
> Since I'm guessing none of you live in Winnipeg and feel like coming over
to
> help, I'm wondering if I were to post pictures if you guys would be able
to
> use them to guide me by either explaining what's in a picture or labelling
> it, etc. I have the Haynes manual and the AMC Jeep: Super Shop Manual by
> Clymer to assist with naming stuff and finding out where it belongs or how
> to remove/install it.
>
> Here's a link to a page with the pictures I've taken so far:
> http://members.shaw.ca/thegryffy/
>
> or a zip file with all 14 pictures:
> http://members.shaw.ca/thegryffy/jeep/allpics.zip
>
> Thank you to anyone who can help at all or direct me to a place that can.
>
>

Sounds like a fun project. I have lots of spare time and don't mind
helping, but you are a bit far away to drive to....

For starters, the wiring schematic in the Haynes manual is spot on for
the 85 CJ7. I have rewired burned harnesses using it. You can also get
kits like the painless wiring harness to replace yours or even get one
from a dead Jeep. The harness all comes apart in modules at the fuse
panel. There is one main bolt in the center you take apart and the
different sections just unplug.

I have tossed most of my emissions crap except for the parts that make
it run better.

I kept the PCV system which includes the charcoal canister. The
canister is the vent for the gas tank and carb float bowl and is really
needed or you will have nasty gas fumes all the time. There is a
solenoid thing at the back of the carb where the PCV line mates up with
the line to the canister before they go into the manifold. This can be
tossed and a straight 'T' Fitting can replace it.

The canister gets turned on via a ported vacuum signal that goes through
the CTO valve just below the carb and it can go through the thermostat
inside the air filter that also feeds the EGR valve. That way the
canister only turns on when you are at speed and fully warmed up so you
can just take a T off the line right at the EGR to go to the canister
purge signal. If you are dumping the air filter, then just feed it
ported vacuum through the CTO.

I also kept the air filter and it's hot air flaps with the heat tube
because I drive in winter and having a carb turn into a block of ice at
60 mph on the Yellowhead Highway only needs to happen once to convince
me they need warmed air in the winter.... This requires a manifold
vacuum line to feed it and that shiny flexible heat tube down to the box
on the exhaust manifold. Canadian tire sells replacement tubes.

Canadian tire sells a heavy duty manual choke kit that has all the parts
to replace yours. They have a regular kit too, but you want the heavy
one. They also sell carb kits. Kits are cheap.

I 'think' you have the same Ford emissions computer that screws with the
timing advance as the 6 has so you can easily disable it by wiring the
ignition module directly to the distributor. If you do have this, you
can look at the ignition module that is Waaayyy down on the drivers side
fender below the washer bottle to see where the purple wire that comes
out of it goes. Stock, the purple stops at the plug. The orange goes
to the computer and the computer sends an orange and purple to the
distributor. If the computer has been bypassed, then the purple wire
will be connected to an added in wire that goes directly to the purple
wire at the distributor. When I do the bypass, I add 2 new wires into
the loom rather than mess with the mess that is already there. Here is
a good link on doing this:

http://home.sprynet.com/~dale02/ignmods.htm

You also should brows around Dale's site, it is excellent:
http://home.sprynet.com/~dale02/list.htm

Then Backfiring, means firing on the back side of a valve which usually
shoots a shot of fire either down the exhaust tube or out the carb. It
doesn't usually hurt pistons. You should do a valve job anyway or send
the head out for one. It isn't too expensive.

A digital camera is your friend when taking things apart. So is some
masking tape you can put on wire ends so you know where they go back to.

Be 'very' careful to put parts back in the exact place they came from.
Things like pushrods should be stuck into cardboard in order. Some are
hollow, so don't use foam to stick them in. If the rod caps and bearing
journal caps aren't numbered, number them before you take them apart.
They all were machined in place, so they must go back in exactly the
same place.

There is a start for you anyway.

Mike
86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
88 Cherokee 235 BFG AT's
Canadian Off Road Trips Photos: Non members can still view!
Jan/06 http://www.imagestation.com/album/pi...?id=2115147590
(More Off Road album links at bottom of the view page)

griffin wrote:
>
> Hey all,
>
> I haven't posted on here in a few years since my Jeep died and I just parked
> it. Anywho, I've decided to pull the engine and with the help of my dad and
> Jeeping buddies, hopefully do my first successful rebuild. With the
> condition of the Jeep, it probably isn't worth the time and money but it'll
> be a learning experience for me and I'd rather mess up on this P.O.S. and
> have a better idea how to fix the next Jeep I buy (which hopefully is
> better). My first problem with this Jeep is the fact that there have been
> more hands touching this baby than a cheap prostitute. The engine bay is,
> needless to say, a mess. There are wires that go nowhere, throw-together
> connectors to bypass stuff, and all these hoses and smog controls that are
> just plain silly. I'm looking for help from you guys as to how to strip this
> thing down to its bare essentials. Keep in mind I want NOTHING extra in
> terms of smog controls and stuff as the laws here are very lax.
>
> The background on the Jeep:
> '85 CJ7 4cyl 150cid, 5spd, pretty much stock from what I can tell. The back
> cylinder has really low compression (the front 3 are around 120 if I
> remember correctly and the back one is like 80 however I'd have to do
> another test to remember exactly). It's also blowing a lot of blue smoke out
> the back so I'm guessing it's burning oil somewhere inside but I haven't
> taken the top off yet to see where the problem is.
> A quick review of what happened when it died - I was offroading and it just
> "died". A Jeep mechanic here managed to get it running but it kept
> backfiring. With the help of you guys we ended up replacing the timing chain
> and a bunch of misc electrical parts were replaced or tested (electrical
> coil, plugs, plug wires, fuel filter, etc) as well as bypassing the ignition
> module, and then it was tuned (a very half-ass job). Now it at least runs.
> I'm wondering if all that backfiring didn't damage the cylinder?
>
> Anyways, like I said - once the engine is out and down to the bare
> essentials, my dad can walk me through a rebuild. However, he has no idea
> what all the hoses, wires, and extra parts inside are for or if any of it
> even needs to be there. We want to get rid of the fuel recovery unit,
> solenoid, auto choke, breather system & air filter, pollution controls, etc
> if at all possible as well as anything else that doesn't need to be there
> just to clean it up and make the job simpler.
>
> Since I'm guessing none of you live in Winnipeg and feel like coming over to
> help, I'm wondering if I were to post pictures if you guys would be able to
> use them to guide me by either explaining what's in a picture or labelling
> it, etc. I have the Haynes manual and the AMC Jeep: Super Shop Manual by
> Clymer to assist with naming stuff and finding out where it belongs or how
> to remove/install it.
>
> Here's a link to a page with the pictures I've taken so far:
> http://members.shaw.ca/thegryffy/
>
> or a zip file with all 14 pictures:
> http://members.shaw.ca/thegryffy/jeep/allpics.zip
>
> Thank you to anyone who can help at all or direct me to a place that can.