Mercruiser 5.7 stalling / restarting issues (1st time post)

P

patrick85048

New Member
Nov 14, 2008
2
Hi. thanks for reading this post.

I have a 1996 Sea Ray 190BR with a 5.7l mercruiser Alpha 1 outdrive. The fuel system is the 2bbl carburetor. I recently picked this boat up from a car dealer and do not have the boats history.

My problem is that if the engine idles for a few minutes and shuts off, I cannot restart it. Last time on the lake I had to be towed off. The next day, the engine starts fine.

I was able to re-create this in my driveway while attaching a residential water source.

I have pulled and replaced all plugs, I checked the timing and it is correct, when I got the boat I drained the fuel tank and replaced the fuel, I have changed the oil and filter, and replaced both batteries.

The on-lake issue occurred when it stalled shifting from forward to reverse. I have the service manual for this engine and have since adjusted the shift linkage to specification. While the linkage was the issue on the lake, it also would not restart in my driveway so I still have the restarting issue.

My family and I have owned boats or PWCs for over 40 years and am very comfortable working on them.

Any advice or help would be greatly appreciated.

Patrick85048
1996 Sea Ray 190BR
5.7l Mercruiser Alpha 1
 
Have you checked and/or replaced your fuel filter and water/fuel separator?
 
When the boat doesn't restart -

1. Pull a plug and attach it to the wire. Ground it on the engine block with a pair of insulated pliers. Have someone crank the engine and observe if there's spark or not. If not, jiggle the shifter back and forth. Try cranking again. If still no spark, look into your ignition system. If spark is present, proceed to step 2.

2. Spray some starting fluid down the carb throat. If it starts, you have isolated the issue to the fuel side of things.

Hope this helps.

Doug
 
I haven't worked on one with a 2 barrel carb but I assume it has an accelerator pump - when it doesn't start does it squirt fuel when the throttle is fully opened?
 
I have this problem occassionally with one engine. It is usually solved by advancing the throttle a bit while cranking. (I intend to resolve this during the spring tune up). Note that this engine idles a bit low. . .I am thinking I need an idle adjustment.
 
Sounds like it could bbe ignition related. Probable could just be a corroded or loose wire harness. I'd at least reset all the harness connections and see if that does not cure your problem Being that old a boat, I would think it is that over a bad fuel pump. It could also be the water/fuel filter too. They would act that way but I have not seen one not be able to restart at all. Good suggestion on the spark. Easy check and that could probably confirm the wire harness issues.
 
What ignition system is it equipped with?

Does it stall after reaching operating temperature?

When you say it wont start back up...does it make an attempt to? or does it just turn over with no hiccups or anything?

Fuel
Compression
Spark
-Check em' all-
 
Hi again and thanks for the replies.

Let me answer all the questions and see if there is a solution:

1. I have replaced the fuel filter and fuel / water seperator
2. I have pulled a plug and checked the spark, it sparks
3. I tried starting fluid and it did not fire.
4. When not starting, if I move the throttle, fuel does spray
5. I have tried strarting with throttle in multiple positions,
none of these positions provide any success
6. I have not checked all the connections but will do so.
7. It has a Thunderbolt ignition and does "hiccup" when trying to refire.

Now to clarify, it always starts cold and runs well. It stalled on the lake once by shifting from forward to reverse while trying to dock. I was able to replicate the situation in my driveway by attaching a hose but I had shut the engine down and it would not restart. The next day, it fired fine.

I'm thinking about sending my carb for a rebuild. If it isn't the issue, it can't hurt since the engine is 12+years old.

Any other ideas?
 
patrick85048 said:
Hi again and thanks for the replies.

Let me answer all the questions and see if there is a solution:

1. I have replaced the fuel filter and fuel / water seperator
2. I have pulled a plug and checked the spark, it sparks
3. I tried starting fluid and it did not fire.
4. When not starting, if I move the throttle, fuel does spray
5. I have tried strarting with throttle in multiple positions,
none of these positions provide any success
6. I have not checked all the connections but will do so.
7. It has a Thunderbolt ignition and does "hiccup" when trying to refire.

Now to clarify, it always starts cold and runs well. It stalled on the lake once by shifting from forward to reverse while trying to dock. I was able to replicate the situation in my driveway by attaching a hose but I had shut the engine down and it would not restart. The next day, it fired fine.

I'm thinking about sending my carb for a rebuild. If it isn't the issue, it can't hurt since the engine is 12+years old.

Any other ideas?
Click to expand...

When you tried starting fluid, did you crack the throttle open to be sure it made its way into the intake? I'm unsure how you could have spark and fuel (your starting fluid was the source in this case), and the engine not start.... unless the plug and wires are bad? You didn't mentioned you changed plugs. I would do that if you haven't already to give yourself a baseline.

Doug
 
Not sure where you are located - does it matter what the outside temperature is? I had a problem with one of my coils which only surfaced when it was really hot and after the engine had run for a bit. I ended up just doing a full tune up - plugs, cap & rotor and wires on both motors and replaced the one coil and haven't had an issue since.
 
douglee25 said:
I'm unsure how you could have spark and fuel (your starting fluid was the source in this case), and the engine not start....
Doug
Click to expand...


Next is compression... I'd test that too. Even if its not the problem you can still see the condition your motors in.

The Thunderbolt 4+5, moslty 4's have had problems with the ICM modules.

Did you only check the spark on one cylinder? Thats kinda what it sounded like to me.

I'd honestly just fork out the money for a complete tune-up and go from there;cap/rotor/plugs/wires. Completely worth it. Carb rebuild isn't going to hurt either. Weber 4Barrel?
 
SR Tech said:
Next is compression... I'd test that too. Even if its not the problem you can still see the condition your motors in.

The Thunderbolt 4+5, moslty 4's have had problems with the ICM modules.

Did you only check the spark on one cylinder? Thats kinda what it sounded like to me.

I'd honestly just fork out the money for a complete tune-up and go from there;cap/rotor/plugs/wires. Completely worth it. Carb rebuild isn't going to hurt either. Weber 4Barrel?
Click to expand...

Well yes, compression would be next, but the OP said it runs when cold. This would lead me to believe it isn't a compression related issue.

I agree with you, go for the tune up and carb rebuild.

Doug
 
If you are tuning it up, replace the coils. I had a similar problem and the coils fixed it.
 
Does it only stall when you are shifting? If so it may be a bad shift cutout switch.
 
Neutral safety switch is a good possibility....
 
I would not risk going rebuilt on the carb. Or anything marine if possible.
Edelbrock makes a nice marine carb.
You can get one at a performance auto parts store.
They have MSD Marine ignition parts also. Dist, Coils, etc.

At least if you are changing parts out trying to find the problem. You are upgrading the boat also.
I left my thunderbolt ignition mounted as a backup.
 
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