Fuel Pump replaced, still issues with warm start.

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dwarren

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Posted - May 18 2015 : 10:02:14 Show Profile Email Poster Edit Reply Reply with Quote Delete Reply
Happened again....no issues the whole day, boat ran strong for couple hours. Cruised slow for a bit then opened her up. No issues.....went to dock for an hour. Started both engines, both started, then starboard stalled....I can hear the electronic fuel pump kicking in. When I spray some ether in the injectors, the boat putters so it's not spark related. I just don't see it being a blockage if it ran fine all day just to stall after sitting hot for an hour.

anyone have any ideas where tos tart? I'm not totally familiar with EFI. I believe I have the mechanical fuel pump as well as some other sort of pump between that and the water sep.

I'm pretty confused...

Douglas Warren
"You never get sumthin' for nuthin'"
 
Doug,
You need to rule out the usual stuff and then bring it to someone who can plug in a diagnostic computer. I had trouble like yours for two years until the ECM finally failed drove me crazy and then Chris over at Delmarine finally was able to figure it out.
Rob
 
Did you try starting with throttle WO to shut down injectors?

Maybe try leaving the engine hatch covers open when leaving for an hour or so ?

Maybe check the IAC to see if it is at all sticky, and if so try swapping with the port one?

The diagnostic scan is always a good idea with injected engines but the scan will not reveal anything like an intermittent bad connection at a relay or fuel pump or harness connector , or hot compartment vaporizing fuel to airlock a fuel pump. But even if the scan shows nothing amiss, that helpfully rules OUT the parameter items checked to narrow list of suspects somewhat.
 
Here's a silly idea, but an easy one. Take a 5 gal pail of ice water and a plastic bag. Duplicate the issue and then cover the fuel pump with the plastic bag to keep the wires dry. Then trickle the ice water on the fuel pump only and use up the whole five gallons. Then see if it starts again easily. If so, you know it's a heat related pump issue. Just keep the ice water off of your hot engine block.
 
Great idea Stephen has. An engine, even one of twins, can heat sink...build up engine temps in an enclosed space without the cooling effects of the cooling system. and opening the engine hatch can help.

I've run into the Idle Air Control(IAC) problem of a dead spot.
 
Doug,
If you think it's heat related try running the blowers continuously. I have to run my blowers whenever the engines are running due to a small engine bay with two engines running at 170 degrees. I also let them run for five minutes after shutting down the engines.
Rob
 
I always have blowers on when engines running. Over weekend, same issue but....motor did start after a few minutes. Still had the pit of the stomach feeling again......Replaced the newly discovered filters and ran motors for a bit after at anchor. Very odd still.....runs like a champ thought (as long as it starts :-)).....

I'll keep nosing around and keep everyone posted.
 
The blower venting system is effective only if all ducting is in place/intact.
 
Check to see if you have a relay labelled starter relay. It is a plug in relay. I had a very similar problem for 2 seasons. Boat ran great and out of nowhere would just die. Eventually she would star and run fine for 30 minutes or 4 hours and then die again. Because the relay was labelled starter relay and the starter engaged, I never thought about it. Just as a desperate measure I took the relay off the other motor (as the motor would not start at all any onager) and plugged it in. Motor started right up. This relay actually controls the electric fuel pump when starting and Once engine is running the fuel pump relay takes over. A 29.00 relay caused me all kinds of grief.
Good luck
 
Okay...happened again...now I'm thinking it has to be fuel pump related. Just doesn't make sense. Anyone know the normal price for one of these (1996 Crusader 270 (efi)). There is no mechanical pump for this motor btw....just feed from water sep filter direct to the electronic pump.
 
Doug,
I'm not sure you should start throwing parts at the problem. I suggest you bring to Chris over at Delmarine (631)598-2946 and let him diagnose the problem. I think you will be surprised at how professional he is and in the end your boat will be fixed and you can go and enjoy it.
Rob
 
As Mercruiser says, always start with "an engine condition check". First check every positive connection, from the battery all the way to the extremities. Check and clean every connector. Often times a loose or corroded connection will cause intermittent problems. Check every ground from the battery all the way to the block. After you have checked all the electrical, turn your attention to fuel. Start at the tank and check the flow all the way. Check every connection for leaks and air aspiration all the way to the injectors. After you have done that, then hook up the diagnostic module.

Years ago I had an intermittent which turned out to be a loose battery cable on the starter solenoid.

It is usually the simple stuff.
 
I've been told "KISS" which stands for "keep it simple stupid" as Greg stated it could be something simple but you have to go thru every connection starting with the ground connections. I would look hard at the connections on the back of the engines and also the cables which can corrode inside out of sight. Good luck and let us know if you figure it out.
Rob
 
Something I shoulda' mentioned before, just got reminded. Should help in locating the starting problem.

The starting circuit has it's own ignition circuit apart from the normal 'RUN' circuit. The same idea that BKair mentioned. It may be the starter solenoid/relay or fuel pump relay.

Forgot to ask earlier. Does the engine turn over and not start or the starter just not run.
 
I would be looking at the engines master electrical cable connection, it wouldn't be the 1st time we have had others with strange problems related to this connection point. This cable brings all of the control and gauge wiring to Merc marine motors.
 
If you don't want to do a diagnostic scan or fuel pressure test , you can always start swapping items you suspect between engines , like the solenoid fuel pump, IAC and maybe a crank position sensor if your EFI has that.
Is this the fuel pump for your engines? http://www.amazon.com/Carter-P74022-Solenoid-Electric-Fuel/dp/B000CSXSTA

But a Wiggle Test of all engine harness and ignition switch wires, both with key On/running when engines are running Ok and with key to Start when it won't, could help aim you in the right direction if it stalls or starts.
 
Okay....so....replaced fuel pump and thought all was well. I ran it up for good half hour running at 3500 or so. Let it cool for an hour and started once, twice.....then sputtered and died. I ran cool water over the fuel lines and block and even loosened the connects to relieve any back pressure in the line. It did finally start.

This either has to be vapor lock or a bad "something else". I figure the $300 fuel pump was the most expensive part but where would you suggest I go next? Hard lines from fuel pump to throttle body and vapor return as well. I can't see anywhere where the lines got "closer" to the engine to promote overheating of the fuel. It's exactly the same as on the other motor. ........

What should I look at next....anyone?
 
Your electric fuel pump is in a squarish reservoir called Vapor Separator Tank (VST), correct? What fills that VST? on our MerC (signature) there's a mechanical engine-driven pump on the block below it. We replaced our electric pump thinking that was is, but it actually turned out to be that the mechanical pump was weak and not filling the VST when the engine was warm. That part was about 1/3 the cost of the electric pump AND it solved our problem, which sounds like yours:

1. Started OK cold

2. Started OK hot right after being shut off

2. But after being shut off 30-60 minutes, either would not start or would start, run a couple minutes, and quit. Then not re-start till it cooled 30-60 minutes
 
No VST, this is high powered (25PSI) pump only fed directly from the tanks via the Water/Sep filter.
 
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