Mercruiser 4.3L TKS starting issue

[outdorzman]

I bought a used 2009 tahoe Q5I SF a few weeks ago. The boat had been winterized. Had shrink wrap on prop and paperwork from dealer to prove it. It was slow to start when I took it out for a test drive. He said it was because of the winterization. I was told it usually just fires right up with just a turn of the key as implyed by the TKS (Turn Key Start) feature. He said after I run it a bit I should have no problems. My issue is this. I have followed the starting procedure as stated in the operators manual. Have ran a tank and a half of gas through it, but everytime I cold start this engine it takes a lot of effort to get her started and stay running.

Following the procedure in my manual after 3 atempts with no start.
prime with full throtle then back to 1/4 still no start.
May start but dies.
Prime 2 times then back to 1/4 usually starts idles at 650 rpm but dies if I put it in gear to back off trailer.

After some fuss in getting her warm I have no issues. Turn key it starts first try. What issues may I have if any or is this normal. This is my first I/O. I have always had outboards in the past.

 

[Don S]

Re: Mercruiser 4.3L TKS starting issue

First of all, it's not fuel injection. You can not start it like a car, and it will not run right until you allow it to warm up. All TKS is, is a primer start similar to an outboard. Again, it is not fuel injection and the engine needs to warm up before using it.
When an engine is winterized, it's usually fogged which causes them to be harder to start after setting for many months.
You may have to pump the throttle a few times and give it some throttle when it start until the fogging oil burns off the plugs and things settle down.

 

[outdorzman]

Re: Mercruiser 4.3L TKS starting issue

Thanks Don. I figured as much. Would changing the plugs vastly improve the starting issue or is it just something to live with. Like I said once it warms up no issues what so ever so I am not sure a plug change would do anything. I have already gone through a tank and a half of gas.

 

[Don S]

Re: Mercruiser 4.3L TKS starting issue

Is it still VERY hard to start when cold? As in setting overnight?
Or does it start and then die after a few seconds of low rpm idle.
If that is the case, just give it some throttle when it starts, say 1000 to 1200 rpm and let it warm up till the temp gauge comes up. Then you should be good to go.

Personally, I think a tuneup to check things every spring is the way to go.
Look at this thread http://forums.iboats.com/showthread.php?t=192804

 

[outdorzman]

Re: Mercruiser 4.3L TKS starting issue

Yeah it only does it after sitting overnight or longer. I just hate tying up the ramp for too long while people are waiting to get in or out. Once out on the lake all starting problems are gone. I am sure a tune up wouldn't hurt. I was just trying to figure if it is something with this TKS system or not? I'm not to familiar with it. A new set of plugs couldn't hurt!

 

[fossill]

Re: Mercruiser 4.3L TKS starting issue

As an '09 model, wouldn't that boat still be under warranty? I thought Mercruiser warranteed their engines for two years?

 

[StitchSC]

Re: Mercruiser 4.3L TKS starting issue

My TKS has been the EXACT same as you describe since she rolled off the showroom floor. You can verify it is working by listening to a "hissing" sound coming from the engine bay for the first few min.

From reading other threads some have this problem, some don't. Some dealers say deal with it, some don't.....I just run it on muffs at home first, or push launch it and fire her up/ let it warm up while tied up at the dock.

I am convinced that every carb'd engine has a unique personality, you just have to learn what it is and go with it.

Have fun, be safe!!

 

[ENSIGN]

Re: Mercruiser 4.3L TKS starting issue

Depending on the outside temp some of the engines with the TKS feature can take up to 5min to warm up.Most do not run well when cold and will not throttle up when cold.You can thank the EPA

 

[outdorzman]

Re: Mercruiser 4.3L TKS starting issue

Fossil
Not sure about the warranty as I bought this boat used. Is that transferable? I will have to look into that.

Stitch
It does have the hiss once you get it started for about 5 to 10 minutes. So I know the TKS works, but it doesn't seem to help starting it one bit.

Ensign
Throttle up when cold is one of my biggest problems. Oh yeah, it is also a California compliant motor. I don't know if that makes it worse or not.

 

[StitchSC]

Re: Mercruiser 4.3L TKS starting issue

Fossil
Stitch
It does have the hiss once you get it started for about 5 to 10 minutes. So I know the TKS works, but it doesn't seem to help starting it one bit.

Yeah, TKS is junk, from a lot of observations, this is what I have noticed on mine (and prob yours to)

The first time you crank the engine, our elec fuel pump is not turned on. And the alarm sounds (normal). After I crank, say, 5-10 sec and stop, the second time I crank the alarm doesnt sound (theory is that the initial crank raised the oil press above min psi required to sound alarm) and the fuel pump is now definitely active. I don't understand why the elec pump was not designed to engage any time you crank the engine.

I ---think--- I have also read somewhere in the merc manuals that when you pump the throttle, it tells the TKS that you are trying to accelerate, and disengages it...I will have to look that up again (Way to tired right now)

Who knows, I am definitely not a pro, and TKS is junk! At least I have learned the quirks of it and have become very comfortable with starting my engine when cold.

Good luck, definitely let us know if you find the answer....some love it and report cold start ups no problem, and some hate it with issues like you and me.