2004 5.7 Thunderbolt turns over but won't start

[Armstrong77]

Serial number: OM675896
Boat is moored in the water since July. Did about a 30 mile fishing trip on January 23, boat ran fine. Started it up a few times since then, got harder and harder to start each time also didn't stay idling until warmed up.

On Saturday I tried to start it and no go. Turns over but does not fire. Things I've checked:
- Pulled all spark plugs, each of them has a spark (might not be as blue as it should be)
- Replaced Fuel Water separator filter
- Electric choke looks fine
- Putting hand over the carb confirmed suction
- Sprayed Carb Cleaner into the carb and tried to start, didn't fire
- Since the plugs had spark, I assume it's not an issue with the kill switch
- EDIT electric fuel pump buzzes when the key is on, assuming it's priming and works fine

What I'll check next
- replace the spark plugs
- replace the fuel filter
- ?

Could it be the ignition coil? How would I test that. I'm at a loss on what it could be.

Thanks All!
Jeff.

 

[nola mike]

- Replaced Fuel Water separator filter

- Sprayed Carb Cleaner into the carb and tried to start, didn't fire

Could it be the ignition coil?

1. What was in there? Clean gas or other? How old is the gas?
2. Did it cough/catch at all?
3. No

 

[Armstrong77]

1. I did not have a clear jar to see if what was in the fuel. Poured it in a blue bucket. 200 litres was from September, 100 litres new from January
2. No it didn’t. Didn’t respond to it at all.

 

[alldodge]

Its not the coil, run thru this

 

[nola mike]

Its not the coil, run thru this

Says he's got spark

 

[alldodge]

I read that, but also said doesn't look good, like to confirm

 

[Scott06]

Use a spark gap tester to confirm strength, or spray some starting fluid down carb. if there is any spark at all it will cough.

What is condition of cap rotor and plug wires?

 

[QBhoy]

I would try it using a known fresh fuel source, like feeding it fuel from a small tank of fresh fuel.and after draining carb, if possible. Surely the money would be on the issue being fuel related. carb may have to come off, if she has had any crappy fuel even close to it. Otherwise its time for a compression check.

 

[Armstrong77]

I changed the spark plugs yesterday because it was something simple and easy to write off as not the problem. It was not the problem.

I took Friday off this week and will try the following:
1. Compression Test
2. If 1 passes.... Take the fuel line off the carb (or loosen it) and see if fuel is coming out when cranking
3. Check the distributor cap (not sure what I'm looking for at the moment, will do some research)
4. Remove carburetor and clean it

 

[alldodge]

See if the cap contacts are clean and not corroded, and pickup is clean

 

[Scott Danforth]

Assuming carb induction

What is the battery voltage? What RPM are you getting during cranking?

With a bad battery connection or a weak battery, if you do not get to the minimum cranking speed, it wont fire

Test your fuel in a clear container. A blue bucket wont allow you to see if your tank is water or fuel

 

[Armstrong77]

Just got back from the boat.
- removed fuel line to carb and inspected mesh filter, looks good.
- put fuel line back on loosely and cranked it over and fuel came out, good as well
- replaced the ignition coil because it looked bad and the plug wire broke off inside when trying to remove it. Didn’t help.
- checked the compression on the port side, read 150-160 on all
- checked compression on the starboard side starting with the second cylinder from the back, 150, then the rearmost cylinder, 190?? It was slowly rising by 15psi the longer I cranked it, stopped at 190.
- checked the forward most cylinders on the starboard side and it read zero.

I packed up and left after that but now I’m thinking of going back tomorrow to check the port side to ensure it’s not my compression tester that went bad all of a sudden (190 then 0 then 0?)

So if it is in fact 0psi, anyone have this happen on side by side cylinders and have somewhat good news for me? Stuck valves? Head gasket? Worse?

 

[Scott Danforth]

anything over 150 is suspect. the 190 either has water in the cylinder (leaking manifolds) or oil in the cylinders.

is this a salt water boat? have you inspected your manifolds

 

[Armstrong77]

This has been a salt water boat it’s entire life. California now British Columbia. That sides manifolds are coming off tomorrow. Hoping for a head gasket issue.

 

[Scott Danforth]

This has been a salt water boat it’s entire life. California now British Columbia. That sides manifolds are coming off tomorrow. Hoping for a head gasket issue.

Its almost never a head gasket issue