2001 Mercruiser 4.3 EFI will not restart video 1

2001 SeaRay Sundeck - Mercruiser 4.3 EFI

UPDATE - 08/18/2019 - Fixed

I installed a hot water side check valve, Mercruiser part number 21-862271A 1, and have not had the problem since then. Apparently hot water can back flow around the fuel pump causing it to vapor lock, and this prevents it. I wish I could insert a picture of it, it's not a common part. The part is about 6 inches long, yellow on both ends, blue in the middle with a drain plug. A section of the water hose will be cut out and this installed with hose clamps. Once installed this drain plug will be a part of winterizing. I hope this helps someone.

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This is an update to the original description below.... 8/5/2012

Everybody I've talked to suggests vapor lock. I wasn't convinced, but what do I know... I've been doing a few things that were recommended, especially to keep the temp down in the engine compartment and avoid vapor lock.

1.) Using gas without ethanol, or using ethanol treatment.
2.) Run the bilge blower while underway.
3.) Do not shut the engine off right away, especially after a long run. Apparently there is some hot water from the engine that dumps down into the fuel cooler when you shut off the engine, thus vaporizing the fuel. Letting the engine run for a few minutes allows for cooler water to cycle into the engine before shutting it down.

So far this year I have not experienced the problem, and we've been out several 100+ degree days. Hopefully we do not have that problem again, time will tell....

ORIGINAL DESCRIPTION BELOW......

Experiencing an intermittent problem where the motor will not restart, usually after turning it off. It is usually when it is hot, but not always. Last year it did it at home with the water muffs on. One time I restarted the motor and it ran for about 2 minutes and had the problem. The engine will turn over and try to start, it will kind of sputter, idle about 100 - 200 rpm's, snort and quit. It will eventually start, after setting for an hour or so. One time it had the problem at the ramp as I was launching the boat (early day, engine not hot), I pulled the boat and took it straight to a mechanic and it started and ran fine. It's been hooked up and checked for error codes, but nothing shows up.

Most mechanics I've talked to believe it is fuel related, ethanol or vapor locking. I have stabil's marine formula with ethanol treatment in the gas and it is still having the problem. From this video you can see it appears to be getting fuel. You can also hear the fuel pump.

[LWDism]

I installed a hot water side check valve, Mercruiser part number 21-862271A 1, and have not had the problem since then. Apparently hot water can back flow around the fuel pump causing it to vapor lock, and this prevents it. I wish I could insert a picture of it, it's not a common part. The part is about 6 inches long, yellow on both ends, blue in the middle with a drain plug. A section of the water hose will be cut out and this installed with hose clamps. Once installed this drain plug will be a part of winterizing.

[diegoforest]

I bought the check valve below for like $150. Waste of money. It does not fit where they say to install it. Better Easy fix. Just pour cold water over the gas line and fuel pump when locked.. Done! In Salt water we carry a gallon jug of fresh water. Nerver used it. Ocean seems not to get hot enough as the lakes here in NC to cause a vapor lock yet.

[learman]

Run the blower for 10 minutes after shut down with the engine hatch open. Mercury did a bulletin on this and there is a Mercury kit that is basically another inline fuel pump etc for $500.

[cclark]

Did you ever figure out what was wrong with it? I am now experiencing the same problem.

[simofran]

Hi, I have the same exact problem with the same engine. Any idea where I can buy the piece? (I’m from Europe)

[corypluta]

i had the same issue last summer. Always happened on hot days and after running the engine for a long time. dealer said it was a vapor lock basically. Always started up after the engine cooled. 3 for 4 hrs later. They couldnt give me a fix other than keeping the engine as cool as possible.

[robertross]

Got the same thing going on. Did you find a fix for it?