Re: mileage?
 

Ya, we did the timing chain/rotor test and were about 22 deg off. We never
checked the actual TDC by pulling a plug, though and we HAD moved the
distributor slightly beforehand on a previous suggestion by someone so we
might have messed up the alignment. However, it's timed enough to start, so
we will double-check that in the spring again. Will also look into the rotor
pad ...thanks for that tip!

I'll let ya know what happens ...

"Mike Romain" <romainm@sympatico.ca> wrote in message
news:421D1195.54318844@sympatico.ca...
> I think the 85 has a steel gear and chain set like my 86 has so jumping
> is unlikely but possible.
>
> One sneaky timing thing I don't see mentioned. Under the rotor is a
> felt pad that needs to be soaked with oil. This lubs up the timing
> advance plate and it's sleeve that sits on top of the distributor
> shaft. If this goes dry, the timing will seem to change every time you
> check it or it will stick with no timing advance allowed.
>
> To test grab the rotor and see if you can turn it a bunch with a spring
> loaded snap back. If not, that could be the trouble. It should be
> really smooth and free in the movement.
>
> To check the timing chain, you hand turn the engine with the distributor
> cap off until you reach TDC on the timing mark. The rotor should be
> pointing just before #1 or #6 if the chain is on the right tooth, way
> off if jumped. You then turn it back the other way while watching the
> rotor. The second the rotor moves, you look at the timing mark and that
> gives you the 'slop' in the chain. 15 to 17 degrees is normal for new
> to still good. Get higher and you could suspect a jumped chain.
>
> Mike
>
> griffin wrote:
> >
> > Been through the following:
> >
> > The entire electrical system. Then I had the local Jeep mechanic go
through
> > it all and replace almost all the under-the-hood wiring. He managed to
get
> > it running again after trying to retime it over and over but it only ran
> > when the engine was fully warmed up and it would backfire quite a bit if
not
> > driven at the perfect RPM. Replaced about 15 wires, a couple of
connectors,
> > the distributor cap/rotor/plugs/plug wires. Did diagnostics on all the
> > coils/sensors/etc.
> >
> > The ignition system has been checked.
> > The fuel system has been checked.
> >
> > The only thing left that hasn't been opened up is the TChain cover. When
my
> > Jeep stalled during offroading, I'm thinking the dist cap was wet
> > (unbeknownst to me at the time). When I was getting pulled home, we
tried to
> > pull-start it and it backfired something fierce. That *could* slip the
> > timing chain a tooth from the force, could it not? Oh well, when it's
warm
> > out it's only like a 3-4 hour job to check that and it's the only thing
I
> > can think of. If it is the TChain that has to be replaced, is there any
way
> > to do it without taking the Rad out? Not sure it would survive.
> >
> > --
> > griffin
> > '85 Jeep CJ-7
> > '97 Toyota Corolla SD
> >
> > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > news:421C8FA4.9F571B74@sympatico.ca...
> > > You don't likely have timing chain issues. In order for it to jump a
> > > tooth, the gears must be destroyed. Those chains are good for the
life
> > > of the engine and then some usually. One of my CJ steel sets is now
on
> > > it's 3rd engine incarnation with the exact slop as a new on measured
in
> > > degrees.
> > >
> > > I would be suspecting something electrical like a cracked distributor
> > > cap or even a burnt valve for backfiring.
> > >
> > > Have you checked the amount of play in your chain? Stock new they
have
> > > about 15 deg of slop.
> > >
> > > Mike
> > > 86/00 CJ7 Laredo, 33x9.5 BFG Muds, 'glass nose to tail in '00
> > > 88 Cherokee 235 BFG AT's
> > >
> > > griffin wrote:
> > > >
> > > > Ya I'm gonna do that in the spring ...after I replace the timing
chain.
> > I'm
> > > > not a big fan of trying to drive it home with it backfiring all the
time
> > ;p
> > > >
> > > > "Mike Romain" <romainm@sympatico.ca> wrote in message
> > > > news:421BBDB6.24FB3D74@sympatico.ca...
> > > > > I just did a 4 day bush run and gas station to gas station is 200
> > miles
> > > > > so I get an easy check every trip. It was still 10.9L/100km which
is
> > > > > slightly better than 23 US mpg and I still have that beauty of a
> > > > > Weber-Carter BBD in there... LOL!
> > > > >
> > > > > Just amazing what a $20.00 carb kit every 2 years does for them...
> > > > >
> > > > > Mike