Vapor Lock?

[Tige22ityper]

Hello all!

I am leaving on Thursday for a camping trip, taking the boat with us. I went out today on the boat for a few hours with the kids and it ran just like the day I bought it....perfect.

I went down to the dock about an hour ago to take it off the water and put it on the trailer and it wouldn't fire! F**!! I last drove it at 4pm.......so it had only been sitting for about 4 hours or so..........First time I have ever had a problem starting in the 6 years I have had it. It would turn over just fine, all the gauges worked fine, and all lights, etc were ok. The tank has gas.

Could it be vapor lock? I am hoping I can just let it sit overnight. I am going to run down to the dock at 6am tomorrow and try to fire it again. If it starts, great! If not, I don't know what to try............its the 350 FI Merc, 315 hp.

I have to work all day tomorrow and won't have a ton of time in the evening either, maybe a few hours to figure it out if she won't start in the morning. We are supposed to leave at noon Thursday. If this was your boat, and it didn't start in the morning, and you were under the gun, what steps would you take? What would you begin checking? I don't have a ton of experience with FI motors, just carb. motors.

Thanks in advance! Always appreciate the help on this site!

[R&T Babich]

Sounds fuel related.

Check fuel/water seperator for water. Remove a plug at end of the fuel rail - is there any water?

Check the fuel pump fuse next to the relays on top of the engine.

Check for fuel pressure in the fuel rails. Does pump make any sound when ignition switch turned to RUN?

Fuel tank anti-siphon valve may me be stuck. Pull off hose at fuel tank pickup fitting. Hook up a clean hose and blow into the hose, can you hear bubbling in the tank?

[hoopykat]

How hot was it outside when you went to ride? Seems I've seen lots more problems when the ambient temp was higher outside...fuel lines too close to the engine and are affected by the heat? Hell...it happened to our gas ambulances years ago....it might do the same things to boats now....

Mike

[teachercop]

Questions:

What altitude are you at?
What was the ambient temp of the lake?

Couple of recent threads on this or similiar issue.

Whatever the ultimate problem is, if you encounter this again, get a squirt gun, load up with cold water,,,ice chest water works well, shoot the water on the fuel pump cooler assembly once or twice, you should be good to go...

[Tige22ityper]

Whoa! Lots of good reponses! I do appreciate it!

It was about 70-71 degrees on the lake when I went to ride tonight. Water was probably 63-64 or so. Altitude is about 100-200 feet above sea level. Where is the fuel pump cooler assembly?

R&T: Where is the fuel/water separator located? Same with the fuel pump relay as well as the fuel pump pick up fitting? These sound simple enough to check if I know where they are! I just don't have alot of time working on engines like this.

[teachercop]

Port side, probably has a black plastic cover which may be labeled, Mercury Cool Fuel, follow a fuel line from the top of the engine (from the fuel rail).

The cover pops off easy enough, if you encounter this again, squirt it good with some chilly H20....

[Tige22ityper]

sounds good. I will look for it. Sounds easy enough to find.

[dogbert]

BTW, I just had my fuel pressure regulator go out on me. The engine started alarming. Before it did that, I had several occasions where it would be hard to start after running. That symptom went away since I replaced it.

[dogbert]

Port side, probably has a black plastic cover which may be labeled, Mercury Cool Fuel, follow a fuel line from the top of the engine (from the fuel rail).

The cover pops off easy enough, if you encounter this again, squirt it good with some chilly H20....

Anybody know what purpose the plastic cover serves? Is it ok to leave off?

[TeamAllen]

Here are the other two link regarding this problem.

http://www.tigeowners.com/forum/show...ight=fuel+pump
http://www.tigeowners.com/forum/show...ight=fuel+pump

I'm sure you can run it without the cover. It makes it look finished and kind of keeps the fuel pump wires from dangling around.

[dogbert]

I only mentioned the cover because we intentionally left it off in case we had to service the cooler or any of its components again. On a V-Drive (because everything is backwards and compressed), you have to remove the muffler to get the plastic cover off. The way my service manager explained it, these engines were never designed to go into the boat in this manner.

[Tige22ityper]

Is the fuel pump in the normal spot as a fuel pump on a small block chev?

I am going down to the dock right now to check the spark and the water/fuel separator..........I have a feeling the boat will not be going camping this weekend... Luckily I have a reliable mechanic that does my yearly service that I spoke to today and told me if I can get it in on Monday he will have it done in a few days.........doesn't really help me right now though....

[Tige22ityper]

Well, there is no spark. I pulled the cap and the rotor was turning fine. I am going to replace the coil wire (it didn't look good after pulling it from the coil) and see if there is spark and go from there.

If no spark with the new coil wire, should I attempt to replace the coil itself? Or might there be something else I can do? Man this sucks! Less than 24 hours before we are supposed to head out! Anyone have a part number for the coil off the top of your head? Can I just go to the local auto parts store and get a coil or do I have to get a specific marine type coil for a Mercruiser?

[dogbert]

It might be your distributor cap. If you have the 350 Tournament Mag Mercruiser, you need to change your distributor cap as often as your impeller. My neighbor had the same problem on his '02 Tige just a couple of weeks ago. New cap, problem gone. The rotor is probably fine, but those caps just suck for longevity.

[chpthril]

Check for spark from the coil wire first. If no spark, substitute a plug wire and recheck. Still no spark, check for 12v on + side of "coil primary" and ground pulse while cranking on the - side of "coil primary"

Could be bad wire, coil, pick-up, module.