Cold starting problems

[freeskimon]

My first post. I've spent the past hour or so reading trough the forums - great stuff! I've already learned several things about my motor.<br />Here's my question.<br />I have an 97' 4.3 mercrusier. I have a heck of a time starting it when it's cold but once warmed up - runs great. Last year I had to use starter fluid almost ever time to get it going. I've tried several different methods as far as pumping. I have an auto elec choke which appears to be working fine. I'm considering re-building the carb. <br />What do you guys think?<br />Also, I can not figure out how to lube my throttle linkage. Very stiff. Any ideas on that?

 

[freeskimon]

Re: Cold starting problems

Sorry, Just noticed tom826401 topic is simular to mine but yet different - ?

 

[Don S]

Re: Cold starting problems

Have you done a full tuneup yet? If the plugs, cap and rotor are "Marginal" it will run ok (sortof) when warm, but be hard to start when cold.<br />If the throttle is stiff, you probably need a new cable.

 

[freeskimon]

Re: Cold starting problems

I did do a full tuneup, but I'm at a loss of what to do with this cold crank thing.<br />I tried to remove my throttle lever asemble to gane accsess to the back side - which I'm sure I'll need to do if I replace the cable - but could not find any thing holding it in place from the front.<br />replacing the cable is a good idea. Any recomendations on a good place to buy a new one?

 

[Bondo]

Re: Cold starting problems

When you try to Cold Start it, Pull the Spark Arrester 1st....And, Open the Choke Butterfly......<br />Pump the Throttle........<br />Do you See gas Squirting into the carb. ????<br /><br />My 4.3LX,+ Many others have a problem of the Carb. Bowls draining when not used.......<br />It takes some Cranking to Refill the Carb......<br />Or, In My case, I by-passed the oil pressure cut-off switch to power the Ele. Fuelpump,.. Priming the carb. that way........

 

[freeskimon]

Re: Cold starting problems

Good advise. I'll try that out when I get home tonight. Not sure about the by-pass trick. I'll save that for a last resort.

 

[Bondo]

Re: Cold starting problems

Not sure about the by-pass trick.

I'm Not Advocating By-Passing the Safety Systems built into Your boat........<br />I'm Just Stating what I Did........

 

[trog100]

Re: Cold starting problems

u could try just pouring about a half eggcup full of fuel straight into the carb.. give it full throttle turn the key and after about five seconds it should burst into life.. <br /><br />u dont need a carb even attached to the engine to make it fire up.. it does need one to keep going thow.. he he <br /><br />trog100

 

[deputydawg]

Re: Cold starting problems

If a complete tune up did not help, plugs plug wires, cap and rotor, fuel filters, the works. Next to check is what was posted already, see if your losing prime in the feul lines. Make sure the feul pump is good. The choke may be working well by visual inspection, but make sure it is working properly and is properly adjusted. <br />As a last resort, one I have seen in cars and trucks, poor compression could cause this. Very rare and probably not an issue here. <br />My first year in tech school I studied a unit on tune up procedures. There they taught that every tuneup should include a compression test. <br />For the cost of it, if you want to do a hit and miss until it is fixed, the carb rebuild would be a good idea. Before spending the money check the feul filters, pump, and double check all the ignition componants such as plugs, wires, cap and rotor, etc. The timing should not be off unless the distributor has been monkeyed with, but check timing too.

 

[KRS]

Re: Cold starting problems

low batteries?

 

[Mahoney]

Re: Cold starting problems

Just a thought, but I just cleaned out my fuel tank and added new lines and filters. There is a check valve running into the feed tube to the fuel tank that prevents fuel from flowing back into the tank when the fuel pump is not on. I would guess that if this valve is leaking and fuel is gravitating back into the fuel tank, this would cause the same symptoms until the fuel pump can reprime itself and pump continuous fuel to the carb again.<br /><br />Just something to consider.

 

[Don S]

Re: Cold starting problems

That is NOT what that valve is for. It's an antisiphon valve and prevents fuel from siphoning out of the tank if the line came off or broke. The fuel pump itself should prevent any backflow of gas. If it doesn't, then the pump is bad.

 

[Mahoney]

Re: Cold starting problems

Don, thanks for correcting that, but I don';t understand how this would work. If that line(or any other line in the system did break, how would any gas be prevented from siphoning out of the tank, when that check valve allows gas to flow out of the tank, and would be the first place gas would likely start flowing out since everything behind it is already primed?

 

[Mahoney]

Re: Cold starting problems

I actually found something online explaining this a bit, <br /> http://www.moyermarine.com/faq/5.16.html <br /><br />It sounds like the valve is strong enough to prevent a siphon from opening it yet, still allowes the pressure from the fuel pump to open it.<br /><br />It still stands to reason a symptom of this valve failing would be to allow fuel to move back into the tank if there was an air leak prior to the fuel pump itself, which could be fine and be preventing fuel from moving out of the lines from the pump to the carb, but would then immediately be sucking air if this was a cause.