Help! Diagnosis:Timing chain?
Guest
Posts: n/a
Re: Help! Diagnosis:Timing chain?
River Horse did pass the time by typing:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
Any spark?
Take the primary off the coil stick an old spark plug in there then
and hold it about 1" from the block and have someone crank it.
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
Off one notch would make your engine run like hell, but it would start.
Fully broken and your engine would probably not even crank or there would
be one hell of a grinding noise from the chain cover as the chain gets all
wrapped up.
> 2) Fuel pump broke (but it was replaced about 6 months ago)
Pull the fuel line, crank, check for fuel. What your describing could
be the fuel pump. Is it electric? Thought that old they were usually
mechanical.
> 3) Intake manifold gasket
It would still start but run lean or stall
> 4) Head gasket
Would still start but run poorly and you would either get white
smoke out the pipe (sucking coolant) and oil in the coolant.
> 5) Exhaust Manifold gasket
Still would start, but make a "farting" noise. Sorta like a diesel
running.. puffa puffa puffa
Not sure if the 304 is a non interference engine or not.
That just means if the timing chain goes your engine will not
eat itself by tring to comress an open valve. Very ugly.
I wouldn't suspect engine internals yet. Start with the electrical
including the ignition circuit.
--
DougW
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
Any spark?
Take the primary off the coil stick an old spark plug in there then
and hold it about 1" from the block and have someone crank it.
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
Off one notch would make your engine run like hell, but it would start.
Fully broken and your engine would probably not even crank or there would
be one hell of a grinding noise from the chain cover as the chain gets all
wrapped up.
> 2) Fuel pump broke (but it was replaced about 6 months ago)
Pull the fuel line, crank, check for fuel. What your describing could
be the fuel pump. Is it electric? Thought that old they were usually
mechanical.
> 3) Intake manifold gasket
It would still start but run lean or stall
> 4) Head gasket
Would still start but run poorly and you would either get white
smoke out the pipe (sucking coolant) and oil in the coolant.
> 5) Exhaust Manifold gasket
Still would start, but make a "farting" noise. Sorta like a diesel
running.. puffa puffa puffa
Not sure if the 304 is a non interference engine or not.
That just means if the timing chain goes your engine will not
eat itself by tring to comress an open valve. Very ugly.
I wouldn't suspect engine internals yet. Start with the electrical
including the ignition circuit.
--
DougW
Guest
Posts: n/a
Re: Help! Diagnosis:Timing chain?
River Horse did pass the time by typing:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
Any spark?
Take the primary off the coil stick an old spark plug in there then
and hold it about 1" from the block and have someone crank it.
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
Off one notch would make your engine run like hell, but it would start.
Fully broken and your engine would probably not even crank or there would
be one hell of a grinding noise from the chain cover as the chain gets all
wrapped up.
> 2) Fuel pump broke (but it was replaced about 6 months ago)
Pull the fuel line, crank, check for fuel. What your describing could
be the fuel pump. Is it electric? Thought that old they were usually
mechanical.
> 3) Intake manifold gasket
It would still start but run lean or stall
> 4) Head gasket
Would still start but run poorly and you would either get white
smoke out the pipe (sucking coolant) and oil in the coolant.
> 5) Exhaust Manifold gasket
Still would start, but make a "farting" noise. Sorta like a diesel
running.. puffa puffa puffa
Not sure if the 304 is a non interference engine or not.
That just means if the timing chain goes your engine will not
eat itself by tring to comress an open valve. Very ugly.
I wouldn't suspect engine internals yet. Start with the electrical
including the ignition circuit.
--
DougW
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
Any spark?
Take the primary off the coil stick an old spark plug in there then
and hold it about 1" from the block and have someone crank it.
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
Off one notch would make your engine run like hell, but it would start.
Fully broken and your engine would probably not even crank or there would
be one hell of a grinding noise from the chain cover as the chain gets all
wrapped up.
> 2) Fuel pump broke (but it was replaced about 6 months ago)
Pull the fuel line, crank, check for fuel. What your describing could
be the fuel pump. Is it electric? Thought that old they were usually
mechanical.
> 3) Intake manifold gasket
It would still start but run lean or stall
> 4) Head gasket
Would still start but run poorly and you would either get white
smoke out the pipe (sucking coolant) and oil in the coolant.
> 5) Exhaust Manifold gasket
Still would start, but make a "farting" noise. Sorta like a diesel
running.. puffa puffa puffa
Not sure if the 304 is a non interference engine or not.
That just means if the timing chain goes your engine will not
eat itself by tring to comress an open valve. Very ugly.
I wouldn't suspect engine internals yet. Start with the electrical
including the ignition circuit.
--
DougW
Guest
Posts: n/a
Re: Help! Diagnosis:Timing chain?
River Horse did pass the time by typing:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
Any spark?
Take the primary off the coil stick an old spark plug in there then
and hold it about 1" from the block and have someone crank it.
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
Off one notch would make your engine run like hell, but it would start.
Fully broken and your engine would probably not even crank or there would
be one hell of a grinding noise from the chain cover as the chain gets all
wrapped up.
> 2) Fuel pump broke (but it was replaced about 6 months ago)
Pull the fuel line, crank, check for fuel. What your describing could
be the fuel pump. Is it electric? Thought that old they were usually
mechanical.
> 3) Intake manifold gasket
It would still start but run lean or stall
> 4) Head gasket
Would still start but run poorly and you would either get white
smoke out the pipe (sucking coolant) and oil in the coolant.
> 5) Exhaust Manifold gasket
Still would start, but make a "farting" noise. Sorta like a diesel
running.. puffa puffa puffa
Not sure if the 304 is a non interference engine or not.
That just means if the timing chain goes your engine will not
eat itself by tring to comress an open valve. Very ugly.
I wouldn't suspect engine internals yet. Start with the electrical
including the ignition circuit.
--
DougW
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
Any spark?
Take the primary off the coil stick an old spark plug in there then
and hold it about 1" from the block and have someone crank it.
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
Off one notch would make your engine run like hell, but it would start.
Fully broken and your engine would probably not even crank or there would
be one hell of a grinding noise from the chain cover as the chain gets all
wrapped up.
> 2) Fuel pump broke (but it was replaced about 6 months ago)
Pull the fuel line, crank, check for fuel. What your describing could
be the fuel pump. Is it electric? Thought that old they were usually
mechanical.
> 3) Intake manifold gasket
It would still start but run lean or stall
> 4) Head gasket
Would still start but run poorly and you would either get white
smoke out the pipe (sucking coolant) and oil in the coolant.
> 5) Exhaust Manifold gasket
Still would start, but make a "farting" noise. Sorta like a diesel
running.. puffa puffa puffa
Not sure if the 304 is a non interference engine or not.
That just means if the timing chain goes your engine will not
eat itself by tring to comress an open valve. Very ugly.
I wouldn't suspect engine internals yet. Start with the electrical
including the ignition circuit.
--
DougW
Guest
Posts: n/a
Update: Help! Diagnosis:Timing chain?
Hat in hand I salute you all:
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
Guest
Posts: n/a
Update: Help! Diagnosis:Timing chain?
Hat in hand I salute you all:
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
Guest
Posts: n/a
Update: Help! Diagnosis:Timing chain?
Hat in hand I salute you all:
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
Guest
Posts: n/a
Update: Help! Diagnosis:Timing chain?
Hat in hand I salute you all:
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
When i really dug into it, my 17 year old son had run
the CJ out of gas....
I gotta fix that sending unit...
Thanks for all the ideas.
I learned some good things,
including to check the basics more than once...
Cheers!
~steve
River Horse wrote:
> 1978 CJ with 304 V8, been running fine.
> Starts up from cold this morning.
> Engine is running at ~3,000 rpm to warm up.
> All is normal.
> Take foot off gas pedal.
> RPM drops and POW!
> A single loud POP is heard.
> The starter spins the engine, but the engine does not hit at all. No
> funny sounds, just smooth engine starting, spinning sounds.
>
> Hit the carb with a little starting fluid and it will hit a few times
> and a distint 'whoosh' is heard intermittantly as the right front
> cylinder hits.
>
> My diagnosis guesses:
> 1) Timing chain broke or skipped a notch
> 2) Fuel pump broke (but it was replaced about 6 months ago)
> 3) Intake manifold gasket
> 4) Head gasket
> 5) Exhaust Manifold gasket
>
> More serious engine problems (broken piston, head, crank, etc) don't
> seem likely since there are no funning sound when cranking.
>
> Oh great jeep wizards,
> What is it?
> What are the next things to do to diagnose it??
>
> Thanks ever so much for the suggestions,
> ~steve
>
Guest
Posts: n/a
Re: Update: Help! Diagnosis:Timing chain?
"River Horse" <hippo@comcast.net> wrote in message
news:NtydnZxSJ7mlKOrdRVn-gw@comcast.com...
: Hat in hand I salute you all:
:
: When i really dug into it, my 17 year old son had run
: the CJ out of gas....
:
: I gotta fix that sending unit...
:
: Thanks for all the ideas.
: I learned some good things,
: including to check the basics more than once...
:
: Cheers!
: ~steve
:
I'd swallow my pride for a cheap fix (adding gas) anyday! I never seem to
get off that lucky. LOL
-Brian
news:NtydnZxSJ7mlKOrdRVn-gw@comcast.com...
: Hat in hand I salute you all:
:
: When i really dug into it, my 17 year old son had run
: the CJ out of gas....
:
: I gotta fix that sending unit...
:
: Thanks for all the ideas.
: I learned some good things,
: including to check the basics more than once...
:
: Cheers!
: ~steve
:
I'd swallow my pride for a cheap fix (adding gas) anyday! I never seem to
get off that lucky. LOL
-Brian
Guest
Posts: n/a
Re: Update: Help! Diagnosis:Timing chain?
"River Horse" <hippo@comcast.net> wrote in message
news:NtydnZxSJ7mlKOrdRVn-gw@comcast.com...
: Hat in hand I salute you all:
:
: When i really dug into it, my 17 year old son had run
: the CJ out of gas....
:
: I gotta fix that sending unit...
:
: Thanks for all the ideas.
: I learned some good things,
: including to check the basics more than once...
:
: Cheers!
: ~steve
:
I'd swallow my pride for a cheap fix (adding gas) anyday! I never seem to
get off that lucky. LOL
-Brian
news:NtydnZxSJ7mlKOrdRVn-gw@comcast.com...
: Hat in hand I salute you all:
:
: When i really dug into it, my 17 year old son had run
: the CJ out of gas....
:
: I gotta fix that sending unit...
:
: Thanks for all the ideas.
: I learned some good things,
: including to check the basics more than once...
:
: Cheers!
: ~steve
:
I'd swallow my pride for a cheap fix (adding gas) anyday! I never seem to
get off that lucky. LOL
-Brian
Guest
Posts: n/a
Re: Update: Help! Diagnosis:Timing chain?
"River Horse" <hippo@comcast.net> wrote in message
news:NtydnZxSJ7mlKOrdRVn-gw@comcast.com...
: Hat in hand I salute you all:
:
: When i really dug into it, my 17 year old son had run
: the CJ out of gas....
:
: I gotta fix that sending unit...
:
: Thanks for all the ideas.
: I learned some good things,
: including to check the basics more than once...
:
: Cheers!
: ~steve
:
I'd swallow my pride for a cheap fix (adding gas) anyday! I never seem to
get off that lucky. LOL
-Brian
news:NtydnZxSJ7mlKOrdRVn-gw@comcast.com...
: Hat in hand I salute you all:
:
: When i really dug into it, my 17 year old son had run
: the CJ out of gas....
:
: I gotta fix that sending unit...
:
: Thanks for all the ideas.
: I learned some good things,
: including to check the basics more than once...
:
: Cheers!
: ~steve
:
I'd swallow my pride for a cheap fix (adding gas) anyday! I never seem to
get off that lucky. LOL
-Brian