Re: Mercruiser still ideling after shut off?
Re: Mercruiser still ideling after shut off?
Hey guys I've got a question for you. I have an 06' Tahoe Q4 with a 4.3L Mercruiser 190hp. I purchased it last October and have only ran it about 5 times. I took it out for the 2nd time this season yesterday and it cranked right up after we unloaded it and it ran across the lake just fine. I then turned the key to shut it off and it kept idling kinda rough for about 10 seconds and then died. Well, when I tried to crank it again it would idle for about 5 seconds and then die. The idle was very low, almost like it wasn't getting enough fuel? After about 20 minutes of this I turned it over and while it was idling low I put it in gear and it took off and ran okay. I then adjusted the idle screw b/c it seemed to be idling lower than normal. Then I ran it for a while and it just seemed like it wasn't running right? Sounded a bit different and just felt different all around? Kind of hard to explain exactly what was different, but all you boat owners know what I mean when your boat just doesn't seem right. When loading it up I killed it and it took a good ten seconds again for it to stop idling and die? Anyone have any idea what this could be? I did put stabil in it over the winter.
It sounds like you have too problems to start with one is the fuel may be old or it has water in it at the fuel filter you could remove it and check it for water or varnish it will look like a oil filter but it will read water seperater fuel filter and it should be down on the lower left side at the front of the engine as you sit on your knees looking at the engine, It will unscrew like a oil filter just have a few rags and I use a clean coffey can to poor it into And look at and smell it. Have you ever boughten fuel from a fuel dock marinea while on the water? the other thing that will make it stay running after shuting it off is the idle is to hi, That engine should idle smooth at 640RPMS you will nee to aujust the idle when warm to 640rpms, The right way to do this it unhook the cable at both ends [don't loose all the nut hardware
then rev the enging for a second to clear it out as the engine is coming down to a idle you will want to see on the RPM gauge the idle speed to go down to 640 rpms, But first you should notice as you start to play with it a little [this will take some time to do so hang in there with me on this one] As the engine is coming down you will want to hear and see the enging idle a little higher at first around 750 RPMS then you will want to slowly aujust the idle speed screw down till you hear the engine speed drop down on it's owen to 640 rpsm that drop down is the modual aujusting everything out to get a smoother idle speed, Now you will want to have the idle screw aujusted to the higher side of the idle speed at first then you need to rev the engine up and let it come back down and then you want aujust it so that when at first it will be at 750 rpms and then within 1-3 seconds you will want to here it and see it drop from 750 down to 640 rpms and that is where you will want it to run at so it will run it's best that it can. While doing the "Aujustments" and trying to "Fine Tune" it and find the TIME FRAME [1-3]second of the drop down speed I will some times pull back on the stud a little to see how much more I think I will need to turn the screw down to find 1-3 second Hi idle before it drops down on it owen for a good idle speed and aujust as needed. Now the hard part hooking up the cable might mess up some of that aujustment you just did a little becuase you will need to aujust the cable so it has a little tinshion on the cable to keep it at idle so you will need to turn the black knob back towred the rear of the boat with a varry small amount of pressure on the idle stud arm making it stay closed tight after moving the throttle cable from WOT back down to idle, at the same time rechecking your first idle aujustment making sure with the cable hooked up it still has the idle drop down speed on the hi side of the aujustment, And some times I will need to reaujust the idle screw some more "just a little bit" with the cable hooked up if I can't seem to get it right with the aujustment of the cable aujuster black knob. The reason for the cable tenshion is for some tmes the engine will stay at a hi idle after going to [WOT] it will not close the throttle all the way down and stay up to 2000 rpms in some cases and that is not good or safe at all so you need to look for that also in your cable aujustments after you think you are all done with it. I hope this helps you some, Good luck.
By the way I know it is a lot to do but [IMHO] If you want it right this is the right way to do it.