CJ7 "missing" at highway speeds or under load - HELP!!
 

I have an 85 CJ7 that has developed a nasty habit of missing extremely
bad at highway speeds or when pulling a utility trailer (when the
engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
and control module - all of which produced nothing except a much
lighter wallet. The fuel filter is only about 1 year old.

NOW for the manifold leak. It has had an exhaust manifold leak for
some time (I know I need to address that issue also). The issue
(missing) started after I drove the jeep 6 hours to the beach, (so I
could run it on the sand) all week at the beach, and did not have a
problem - until 30 minutes into the return trip. It seemed as soon as
I let the engine cool off, I could go about 60 miles until it started
acting up. Since then it has gotten much worse. I can drive it around
town and it seems OK until I hit the highway.

All of this said I started thinking that I might have a burnt valve
caused by the manifold leak, but I wanted some other opinions before I
pulled the head.

Any help would be great, because I would really like to get the "Green
Goblin" back on the road.
Thanks.

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

The cold air from a cracked exhaust manifold can easy warp an exhaust
valve. A compression test with a little oil will find it:
http://www.georgiazclub.com/tips/ztech/comptest.htm
But you're describing an ignition misfire, and I've cooked a set of
plugs in a quarter mile. You didn't say you replaced the ignition wires,
which without the special pliers to pull them are easily damaged.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/


"Shadow" <timstephenson@bellsouth.net> wrote in message
news:1189125658.835943.311810@22g2000hsm.googlegro ups.com...
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>



--
Posted via a free Usenet account from http://www.teranews.com

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

The cold air from a cracked exhaust manifold can easy warp an exhaust
valve. A compression test with a little oil will find it:
http://www.georgiazclub.com/tips/ztech/comptest.htm
But you're describing an ignition misfire, and I've cooked a set of
plugs in a quarter mile. You didn't say you replaced the ignition wires,
which without the special pliers to pull them are easily damaged.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/


"Shadow" <timstephenson@bellsouth.net> wrote in message
news:1189125658.835943.311810@22g2000hsm.googlegro ups.com...
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>



--
Posted via a free Usenet account from http://www.teranews.com

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

The cold air from a cracked exhaust manifold can easy warp an exhaust
valve. A compression test with a little oil will find it:
http://www.georgiazclub.com/tips/ztech/comptest.htm
But you're describing an ignition misfire, and I've cooked a set of
plugs in a quarter mile. You didn't say you replaced the ignition wires,
which without the special pliers to pull them are easily damaged.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/


"Shadow" <timstephenson@bellsouth.net> wrote in message
news:1189125658.835943.311810@22g2000hsm.googlegro ups.com...
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>



--
Posted via a free Usenet account from http://www.teranews.com

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

The cold air from a cracked exhaust manifold can easy warp an exhaust
valve. A compression test with a little oil will find it:
http://www.georgiazclub.com/tips/ztech/comptest.htm
But you're describing an ignition misfire, and I've cooked a set of
plugs in a quarter mile. You didn't say you replaced the ignition wires,
which without the special pliers to pull them are easily damaged.
God Bless America, Bill O|||||||O
mailto:-------------------- http://www.----------.com/


"Shadow" <timstephenson@bellsouth.net> wrote in message
news:1189125658.835943.311810@22g2000hsm.googlegro ups.com...
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>



--
Posted via a free Usenet account from http://www.teranews.com

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

Shadow wrote:
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>

How's your timing chain?

tw

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

Shadow wrote:
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>

How's your timing chain?

tw

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

Shadow wrote:
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>

How's your timing chain?

tw

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

Shadow wrote:
> I have an 85 CJ7 that has developed a nasty habit of missing extremely
> bad at highway speeds or when pulling a utility trailer (when the
> engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> and control module - all of which produced nothing except a much
> lighter wallet. The fuel filter is only about 1 year old.
>
> NOW for the manifold leak. It has had an exhaust manifold leak for
> some time (I know I need to address that issue also). The issue
> (missing) started after I drove the jeep 6 hours to the beach, (so I
> could run it on the sand) all week at the beach, and did not have a
> problem - until 30 minutes into the return trip. It seemed as soon as
> I let the engine cool off, I could go about 60 miles until it started
> acting up. Since then it has gotten much worse. I can drive it around
> town and it seems OK until I hit the highway.
>
> All of this said I started thinking that I might have a burnt valve
> caused by the manifold leak, but I wanted some other opinions before I
> pulled the head.
>
> Any help would be great, because I would really like to get the "Green
> Goblin" back on the road.
> Thanks.
>

How's your timing chain?

tw

Re: CJ7 "missing" at highway speeds or under load - HELP!!
 

On Sep 6, 8:54 pm, "L.W. \(Bill\) ------ III"
<LWBillHug...@------.net> wrote:
> The cold air from a cracked exhaust manifold can easy warp an exhaust
> valve. A compression test with a little oil will find it:http://www.georgiazclub.com/tips/ztech/comptest.htm
> But you're describing an ignition misfire, and I've cooked a set of
> plugs in a quarter mile. You didn't say you replaced the ignition wires,
> which without the special pliers to pull them are easily damaged.
> God Bless America, Bill O|||||||O
> mailto:LW------...@aol.comhttp://www.----------.com/
>
> "Shadow" <timstephen...@bellsouth.net> wrote in message
>
> news:1189125658.835943.311810@22g2000hsm.googlegro ups.com...
>
>
>
>
>
> > I have an 85 CJ7 that has developed a nasty habit of missing extremely
> > bad at highway speeds or when pulling a utility trailer (when the
> > engine is hot). I have replaced the plugs, coil, dist. cap & rotor,
> > and control module - all of which produced nothing except a much
> > lighter wallet. The fuel filter is only about 1 year old.
>
> > NOW for the manifold leak. It has had an exhaust manifold leak for
> > some time (I know I need to address that issue also). The issue
> > (missing) started after I drove the jeep 6 hours to the beach, (so I
> > could run it on the sand) all week at the beach, and did not have a
> > problem - until 30 minutes into the return trip. It seemed as soon as
> > I let the engine cool off, I could go about 60 miles until it started
> > acting up. Since then it has gotten much worse. I can drive it around
> > town and it seems OK until I hit the highway.
>
> > All of this said I started thinking that I might have a burnt valve
> > caused by the manifold leak, but I wanted some other opinions before I
> > pulled the head.
>
> > Any help would be great, because I would really like to get the "Green
> > Goblin" back on the road.
> > Thanks.
>
> --
> Posted via a free Usenet account fromhttp://www.teranews.com- Hide quoted text -
>
> - Show quoted text -

Thanks for the advise on compression check - I'll give that a try;
and I did replace the wires along with the plugs, I just forgot to
mention.
-Shadow