4.3 not running like it should...where to start?

[alldodge]

Sure glad to hear there was no issue with it running. Right now I would figure your timing is good. As for the black, that can be the engine was running rich and its just spitting the carbon out. Run it and see how it performs. My guess your plugs are pretty black and being set at 0 instead of 8 BTDC could be the issue

 

[CurrentObsession]

Oh man.....
​Just did the compression test. Started out at cylinder that had the plug with no electrode (furthest back post side) If numbers on intake mean anything it was # 5. Pull plug out and it looks real bad, electrode wasn't fried off but lots of carbon. Hook up the hose remove lead from coil, turn over the engine, nothing registers on the gauge. Must have done something wrong, switch to the opposite side back plug (# 6 I think) as its the second easiest to access. Hook up meter like before get a reading of 180PSI. Go back to #5 and no reading............What am I looking at now? I have a bad feeling about this......

 

[alldodge]

Oh man.....
​Just did the compression test. Started out at cylinder that had the plug with no electrode (furthest back post side) If numbers on intake mean anything it was # 5. Pull plug out and it looks real bad, electrode wasn't fried off but lots of carbon. Hook up the hose remove lead from coil, turn over the engine, nothing registers on the gauge. Must have done something wrong, switch to the opposite side back plug (# 6 I think) as its the second easiest to access. Hook up meter like before get a reading of 180PSI. Go back to #5 and no reading............What am I looking at now? I have a bad feeling about this......

I think you burned a hole in a piston, its overhaul or another block. Need to pull the head

 

[CurrentObsession]

I think you burned a hole in a piston, its overhaul or another block. Need to pull the head

Okay

​That's what I figured...... The needle didn't even move, if it where the valvetrain it would have at least moved right?

Could a not properly tightened up spark plug be the cause of a hole in the piston? Reason I ask is I am trying to access what the likelihood of my issues all being resolved with a rebuild are, or whether that is just the start of the trouble shooting again.

Thanks

 

[alldodge]

Just guessing, but IMO I see it as running lean. If the plugs are kind of brown or gray with maybe some black then its just the one cylinder. What do the other plugs look like?

If could be a bent exhaust valve but if that happens there is usually some back firing from hot gasses passing by from the other cylinders when the fuel is coming in.

 

[Fun Times]

Sorry to hear of your no compression in that cylinder. The damage could be either or 'Or both. And like mentioned by AllDodge, if it's a valve issue you may get backfire type sounds but definitely a performance loss that could happen slowly or all of sudden depending on damage.

If you're going to wait to remove the head but are interested in knowing what things look like inside the cylinder then if you happen to own, or know of someone who owns an inspection camera then you could have a better look around to see what the issue may be. I believe you could rent one form either a auto parts store or home depot. The Inspection Camera For Android Phones seem pretty neat too.

http://www.ebay.com/sch/i.html?_odkw...meras&_sacat=0

 

[CurrentObsession]

Sorry to hear of your no compression in that cylinder. The damage could be either or 'Or both. And like mentioned by AllDodge, if it's a valve issue you may get backfire type sounds but definitely a performance loss that could happen slowly or all of sudden depending on damage.

If you're going to wait to remove the head but are interested in knowing what things look like inside the cylinder then if you happen to own, or know of someone who owns an inspection camera then you could have a better look around to see what the issue may be. I believe you could rent one form either a auto parts store or home depot. The Inspection Camera For Android Phones seem pretty neat too.

http://www.ebay.com/sch/i.html?_odkw...meras&_sacat=0

​Great idea about the camera and as luck would have it I have a mini Ridgid plumbing one. I assume I would simply insert it into the spark plug hole?

​BTW I took off the valve cover (surprised it was plastic...lol) and cranked the engine over to see if the valves went up and down and it looks like I think it should. I did notice something that may mean something....Looked like gas was shooting out of the exhaust on the front 2 cylinders but nothing out of the #5....Does that help with the diagnosis?

 

[alldodge]

Don't change anything from my side

 

[alldodge]

What does the other plugs look like

 

[CurrentObsession]

What does the other plugs look like

​I haven't pulled them yet, how hard is it to pull the head off? Looks like I have to take intake off.

 

[alldodge]

​I haven't pulled them yet, how hard is it to pull the head off? Looks like I have to take intake off.

You have the exhaust off but no plugs, sure hope you don't put the plugs in before the exhaust is back on

Yes, the intake needs to come off first, then just remove the head bolts

 

[CurrentObsession]

You have the exhaust off but no plugs, sure hope you don't put the plugs in before the exhaust is back on

Yes, the intake needs to come off first, then just remove the head bolts

​I took the exhaust manifold off mainly to get the valve cover off, it didn't look like it would come off otherwise.

To clarify......what I believed to be fuel coming out of the exhaust was coming out of the heads with the x manifold off. I didn't have the plug in #5 though.

 

[CurrentObsession]

I'm trying to get the head off now. I have the coil mount and 3 bolts that come from the front that attached the oil filter, drive oil container and the front belt tensioner brackets out, looks like I need to get the intake off next.

Does the distributor come out first?

 

[alldodge]

Does the distributor come out first?

Yes, remove before the intake

 

[CurrentObsession]

Thanks to everyone that chimed in on my situation......This site is the best!

​I have decided its too much for me to handle so I took the boat in to have a reman engine swap done locally at MichiganMotorz. Should be done by next week. $2300 for motor, $1250 labor including a new impeller.

​I just hope it wasn't a part like a bad distributor that caused my piston hole that will be going into the new engine. They said they will check it all one while swaping over.

 

[Bondo]

​I just hope it wasn't a part like a bad distributor that caused my piston hole that will be going into the new engine. They said they will check it all one while swaping over.

Ayuh,.... Probably the Most common cause of detonation in boats is bad fuel, 'n bad fuel delivery,.....

Make darn Sure the boat's side of the fuel system is up to snuff, so ya don't smoke the new motor,.....

 

[CurrentObsession]

Ayuh,.... Probably the Most common cause of detonation in boats is bad fuel, 'n bad fuel delivery,.....

Make darn Sure the boat's side of the fuel system is up to snuff, so ya don't smoke the new motor,.....

​I was thinking the same thing after researching causes.

Other than checking the fuel filter for water what would you recommend?

 

[Bondo]

The boat's side includes the vent, the fill hose, the tank, the fuel in it, the diptube, the anti-siphon vale, 'n the hose to the fuel filter,.....

All of it needs to be A-Ok, 100% up to it's task,.....

 

[Boisebiker]

I feel like I just read a book and the last 10 pages are missing. Is there an end to this story or has it not been written yet?

 

[Bondo]

I feel like I just read a book and the last 10 pages are missing. Is there an end to this story or has it not been written yet?

Ayuh,.... Please read rule 12,.... sorry, thread closed,.....