Not starting after initial run

[coolings]

This week I put my boat back in the water for the first time this season. In December, I did my annual maintenance. I did not fog the engine. I filled up the fuel tank and added some sta-bil. I replaced the fuel filter. The engine starts fine when first launched. I run it for about 45 minutes and then sat for several hours. Enough time for the engine to cool back down all the way. When I go and try and restart the engine, it turns over and then dies. I tried for awhile and it would not start. I had to throttle up to get it started. This happened two days in a row. The first day I burned 14 gallons of fuel and topped the tank off between the two outings. Someone mentioned I might have water in my fuel. After the second time, I added another 14 gallons, but haven't run it since.

My engine is still under warranty. Should I bring it back in for service? Or should I wait until the next outing to see if the new fuel will solve the problem.

 

[BonBini]

Check a few things out first before you haul it in. Start by pulling your fuel filter, dump it into a bucket and check for water.

 

[Dave S]

You didn't mention if the engine will idle after you finally get it restarted. If it won't then it could be the Idle Air Controller or the IAC muffler. Read ths posting to see if it describes your problem especially the part about restarting your engine. http://clubsearay.com/forum/showthread.php?t=27561&highlight=controller The IAC will be covered under warranty.

Dave

 

[coolings]

Initially I could not idle. I had to drop back to the center and then quickly into gear. The idle seemed to be low. It would kind of sputter lowly. Dave I could not go to the link you posted. It said I did not have permission to view that page.

 

[Dave S]

Initially I could not idle. I had to drop back to the center and then quickly into gear. The idle seemed to be low. It would kind of sputter lowly. Dave I could not go to the link you posted. It said I did not have permission to view that page.

I am not sure why you couldn't view it so I have copied my initial posting from that thread:

EDIT NOTE-

I have edited this posting as of 02/22/10 to include some additional information and answer some of the questions brought up in the replies. All new comments are in red.

It should be noted that my comments are based on my own personal experience with my 5.0 and 350 MAG engines that both had Multiport Fuel Injection.Since the 6.2 is the same basic block, then chances are it could experience similar issues. Many folks on CSR have posted about their own similar IAC problems as well and you can search the individual postings for more information if you wish. I cannot tell you if these problems are also routinely encountered with 4 cylinder engines, V6 engines, or V8 big blocks.

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The Idle Air Controller (IAC) on Multi Port Fuel Injected engines maintains the idle at the proper RPM. There are also IAC valves on Throttle Body Injected motors but the IAC valve is different. For purposes of this post I am only dealing with the IAC as it is installed on the MPI versions of the 5.0, 6.2, and 350 MAG engines.

Based on my own personal experience and the many postings I have seen here on CSR and other Boating Boards, the IACs on Multi Port Injected small block V8 motors seem to fail quite frequently.I just had my IAC fail on me yesterday out on the water (more on that later) and I also had two failures on the 5.0 that was in my 240 Sundeck. As a result of this, I have always carried a spare since that first time it happened since it it is very difficult to dock and maneuver a boat whose motor will not idle. :smt101:smt043

So yesterday while I was cruising along, the dreaded alarm went off and “Check Engine” popped up on my Smartcraft display. There was no other information available from Smartcraft (something I think Mercury ought to change:smt013) but as soon as I slowed the boat to an idle the motor stalled. I pretty much suspected that the IAC was the culprit but I wanted to check it out further.

How do you restart one of these motors that won't idle? On an outdrive boat you have to first depress the throttle neutral lock out on your throttle control and that allows you to advance the throttle part way past the neutral point so you can crank the engine and the motor will start. (Be very careful you don't over-rev the engine:smt009). (Edit Note......also check out FLFLRATE's comments about starting an engine with a bad IAC a few replies down as well). Once I restarted the engine I double checked all my gauges and looked at all the Smartcraft displays and everything looked normal to me. So I decided to see if I could still drive the boat. Now realizing you cant return the throttle to idle or it will stall, you quickly have to bring it back to the neutral spot and then just as quickly put it into forward and give it some throttle before it stalls. Once underway at about 2000 RPMS, the Check Engine warning did not re-appear. But I was getting two short alarm beeps about every minute and as soon as I sped up the one long beep sounded along with another Check Engine warning. So I shut the motor down, deployed the anchor, and went to work changing the IAC out on the water. Once it was changed, the motor started fine and idlled fine and did not sound an alarm or display the Check Engine warning either. PROBLEM SOLVED!:thumbsup:

This brings me to the other part of my post and that is how to change the IAC. It is very easy to change one, but there are a few caveats to mention so I though I would post this “how to” along with some pictures. First off the IAC is located directly under the intake decorative cover.

Remove the cover and the IAC is easy to spot. In this picture the new one is in place and it is the unpainted silver unit you see here right behind the flame arrestor cover.

First unplug the connector on the unit shown here.

Then use a 3/16th allen wrench to remove the two bolts on either side of the IAC. The IAC shoud lift off but if you have the original unit on your motor the IAC may not want to come loose because the engine paint is holding it together (which was my case). Directly below the valve itself is a mounting body with two air hoses attached to it. If you cant get the IAC valve loose from the bottom mounting plate, my recommendation is to loosen up the hose clamps on the side of the mounting plate and remove the air hoses which will allow you to take the whole assembly off. (The picture below shows this mounting plate and the two hoses I mentioned.)

Then you can use a screw driver or putty knife to separate the IAC itself from this mounting plate. Be aware you may damage the gasket and you need to carry a spare gasket as well. I slightly damaged my gasket but not badly enough that I couldn’t re-use it to get back to the dock ao I could bring a gasket scraper from home to remove the old gasket and install my new one.

Edit note..........There is an IAC "muffler" in a slotted area just inside the throttle body under the flame arrestor. I do not have a picture to show you but I have included this parts explosion diagram to explain where to find it.

It may be difficult to see the part reference numbers but the muffler is just a small rectangular piece of foam and is shown as reference number 6 just sbove the round opening to the throttle body intake above. If you cant see the numbers you can probably see that block in the diagram and that is the muffler. That muffler goes into a slot (just above the butterfly) inside the throttle body opening. If the muffler is dirty you may not even know it is there because it just kind of blends in with everything. You can remove it with a pair of needle nose pliers. Here is a picture of the one that came out of mine and it is sitting on a piece of letter size paper so you can get an idea of how small it is.

This piece of foam is called a muffler because that is what it is designed to do. Without it your engine could have an audible whistling noise from the IAC air vacuum. After talking with our Merc techs today, they also confirmed these mufflers shoud be changed regularly because if they plug up they can cause the IAC to fail. The part number for the muffler is 35-863829


So just be aware that this problem may strand you on the water if you don’t have a spare IAC and Gasket or don’t know how to deal with the problem.

 

[Lazy Daze]

Start with the easy stuff like Ron said. I'll only add that it may help to see what you've got if you pour it in a clear container like a pickle jar. You may want to remove the pickles, first.... :wink:

Dave - he's got a carb'd 5.0 - no IAC. Unless I'm missing something?

 

[coolings]

I do have a carb. I will check the fuel filter. Thanks, Mike

 

[Dave S]

Dave - he's got a carb'd 5.0 - no IAC. Unless I'm missing something?

Hmmmmmmmmmmm...........a 2008 model with a 5.0 V8 and a Carb? :wow: I didn't know such a variant existed. :smt017:smt017:smt017

 

[Lazy Daze]

Hmmmmmmmmmmm...........a 2008 model with a 5.0 V8 and a Carb? :wow: I didn't know such a variant existed. :smt017:smt017:smt017

Only in the "Sport" line - the Selects and Sundecks have the MPI as standard issue. 'Course, that's all changed with the wonderful addition of ECT... yippie. Can you tell how excited I am? Except for the V-6, that will still be available as carb'd.