2001 Mercruiser 4.3 efi restart problem

dbach

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Jun 4, 2004
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I have a 2001 Sea Ray 280 Sundancer. Initially these engines crank,warm up and run perfectly. Because they are efi's I don't touch the throttles to start them. If I run for an hour and then stop for lunch, etc. they won't restart for a couple of hours. It sounds like vapor lock or no gas or flooding. My dealer can't seem to fix. Anyone heard of this problem?
 

JB

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Re: 2001 Mercruiser 4.3 efi restart problem

Moving to I/O
 

highaltitude

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Re: 2001 Mercruiser 4.3 efi restart problem

i have encouuntered several 4.3 mercruiser that have a vapor lock problem. when the engine shuts down the warm water flows downward-into the cool fuel box-causing a vapor lock condition. mercury sells a brady valve that goes between the thermostat housing and the cool fuel box. basically a one way check valve. money says this solves your prob. p.s. the winterization procedure will change if this valve is installed.
 

vinney

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Oct 29, 2002
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Re: 2001 Mercruiser 4.3 efi restart problem

Vapor lock. Mercruiser has a low pressure fuel pump that is installed in the beginning of the fuel system to keep it from turning to vapor. The vapor lock problem is at the in side of the electric fuel pump. If you keep the fuel under pressure it will not vapor lock. If you are going to install this yourself THE installation had to be done to code. ABYC or USCG. Volvo Penta puts there electric fuel pump at the beginning of there fuel system and They don't have this problem. Holley makes a marine electric low pressure fuel pump and Carter makes two low pressure electric fuel pumps that will work.
 

highaltitude

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Re: 2001 Mercruiser 4.3 efi restart problem

is this a volvo or a mercruiser!! do your homework-contact your local mercury dealer.
 

dbach

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Re: 2001 Mercruiser 4.3 efi restart problem

These are Mercruisers. They have been to the dealer twice to be fixed. The last time they replaced a part in the distributor as per a Mercruiser bulletin from last summer. The problem actually got worse after that. (Initially only the starboard engine wouldn't restart, now neither will!)<br /><br />The gas I use comes from two reputable marinas. <br /><br />This is a hard problem for a dealer to replicate. I am going to give the helpful ideas from this posting to the dealer. I just want to exepidite their efforts to get me going again. <br /><br />Thank you for your time and suggestions. I'm open to as many as I can get.
 

vinney

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Re: 2001 Mercruiser 4.3 efi restart problem

When the problem happeneds you can bleed the vapor out and refire the engine. You need to find the right guy. This is a major problem on this engine. IF you keep the fuel under pressure the problem will go away. Mercruiser put there fuel pump in the middle of there fuel system. The vapor lock problem occurs right where the fuel enters the fuel pump. A heat soak happends from the engine preheating the fuel after you shut down the engine. If you keep the fuel under pressure its much harder to change to the next state Which when you heat fuel its vapor. 2 to 3 psi. will make the problem go away. A hint for You Manufactures NEVER admit they do anything wrong. There is a kit for that engine to install a low pressure fuel pump at the beginning of the fuel system. The part number is an X on the box.
 

dbach

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Re: 2001 Mercruiser 4.3 efi restart problem

Thanks for the feedback(s) Vinney. Interestingly, I have contacted the manufacturer. They regret that I'm having a problem and have suggested that "Vapor lock can be caused by many things: engine compartment ventilation, length of fuel lines, quality of fuel, etc" These problems would be somebody elses fault! Thanks to you I have asked them to comment on the fuel pump issue. We'll see.
 

vinney

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Re: 2001 Mercruiser 4.3 efi restart problem

Mercruiser will make you jump thru the hoops. Its the way they play the game. They will tell you to run the blower all the time. Lift the engine hatch when you sit for any length of time. Ect. Its a bunch of bull You need to stick with it and not give up. I think some times they think you will go away. They know whats wrong. Mercruiser dosen't wan't to admit it. The good thing for you its a SeaRay They are all one company so they can't blame Searay. If you keep the fuel under pressure at the inside of the electric fuel pump your problem will go away. I have personally install 50 plus extra fuel pumps and Have cured every vapor lock issue. I used the Holley Marine electric fuel pump. I used the Carter one now.
 

jb71

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Aug 31, 2003
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Re: 2001 Mercruiser 4.3 efi restart problem

I am having the same problem with my 4.3, I cleaned the carb initially based on a friend's & this forum's input but that did not do the trick. I had finally come to the conclusion (today) to take it to a dealer to look at, after calling the dealer the service guy said it could be a spark plug problem. He said something about problems with the spark plugs used in these engines tending to fail when they get heated up. Once they cool back down they perform just fine. He suggested trying a higher quality spark plug as a first step (he said that is what they would do)...then replace the thermostat...then something about the corrosion on the sensor wheel under the distributor cap. He suggested I try these on my own before shelling out the $$$ for them to do the same thing (how refreshing to hear). I am not sure if he is on the right track with this, but I am willing to give it a try and maybe it might work for you also. (Does this advice make sense???anyone???)
 

pra100

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Nov 1, 2002
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104
Re: 2001 Mercruiser 4.3 efi restart problem

Vinney<br />Which carter electric pump are you using?Are just using as a booster and mounting it right at fuel tank?I was thinking of doing this ahead of a mechanical pump.This interesting to me and thought it might be a cure for a simular problem I am having.
 

vinney

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437
Re: 2001 Mercruiser 4.3 efi restart problem

ABYC code state the fuel pump can't be mounted any futher than a foot from the engine and the power must run thru an oil pressure switch. The Carter fuel pumps you can run are a low pressure. There is a 25 gph and a 45 gph both low pressure. You can buy the pumps thru Sierra. You can buy the fitting for the ends of the pump thru an OEM. I would recommend you put the supply voltage thru a relay. We ran the Holley marine electric pump when we first found Vapor lock problems in boats. The Holley makes a better quality pump but are much larger than the Carter. The Carter pump is alittle less money.
 

dbach

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Jun 4, 2004
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Re: 2001 Mercruiser 4.3 efi restart problem

Final update - I got great advise from your contributors. My problem is now fixed. The dealer installed 2 Brady valves and 2 booster fuel pumps; one at each engine. No more vapor lock. Both "fixes" were suggested by your replys. Thanks!
 
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