1994 mercruiser 4.3lx stalling problem

[rinkerthestinker]

I recently purchased rinker captiva 190, its my first boat, it fires right up and will run for a bit, then it will stall. Replaced the carb with a brand new one, and the same problem continues. When I have someone move the throttle, the carb does shoot fuel in, so therefore im thinking the fuel punp is good. I changed plugs, fuel/water seperator filter, and oil. It also fires right back up everytime, it gives me no problem to start. Any suggestions on what could be causing the stalling.

 

[CHARGER2]

Re: 1994 mercruiser 4.3lx stalling problem

Is it hard to restart after the stall? Does the accel pump shoot gas in directly after a stall? Sounds like the fuel bowl is draining. Test your fuel system- step 3 in the adults only sticky. Shooting gas in when pumping throttle does not mean the fuel pump is good.

 

[rinkerthestinker]

Re: 1994 mercruiser 4.3lx stalling problem

Ya it starts right back up after every stall, and yesterday b4 it stalled the last time the oil pressure gauge dropped to zero. when it does run it sounds good and after about a min and it stalls again.

 

[Struc]

Re: 1994 mercruiser 4.3lx stalling problem

Really sounds like a fuel problem. Could be as simple as the fuel tank vent is clogged, or the anti-siphon valve is bad.

 

[jkm3093]

Re: 1994 mercruiser 4.3lx stalling problem

Ya it starts right back up after every stall, and yesterday b4 it stalled the last time the oil pressure gauge dropped to zero. when it does run it sounds good and after about a min and it stalls again.

Your fuel pump only gets power either when cranking the starter or oil pressure is present when running as a safety measure. Check why no oil pressure as the oil pressure switch is probably shutting down your fuel pump.

 

[rinkerthestinker]

Re: 1994 mercruiser 4.3lx stalling problem

how would I determine if its the oil pressure switch is ther a way to jumper it out?

 

[rinkerthestinker]

Re: 1994 mercruiser 4.3lx stalling problem

today i ran it and it continued to stall out, but when it was about to stall i would spray some carb cleaner in th carb. it would stop it from stalling, is this any indication of a bad fuel pump. i checked all the fuel lines none seemed to be plugged up, i even ran it without the screen on the fuel line that draws from the tank.

 

[NHGuy]

Re: 1994 mercruiser 4.3lx stalling problem

When it stalls you need to get the flame arrestor off and have someone give it a couple of pumps of fuel. If it squirts you have fuel in the bowl. If not there is a fuel starvation problem. Then unscrew the fuel cap to give the tank more ventilation and see if it runs past the 10 minutes.
If those test don't do anything maybe your motor won't run once the choke opens. Did you set up the idle speed and the main jets when you put on the carburetor? I think on that motor you want idle down around 700 or 650 warmed up. If I am wrong someone will correct. When it's warm and running slowly (650 or so) you then turn down the jets separately til the motor stumbles then back them out til it runs rough and finally find a sweet spot in between. If this changes the idle keep moving it back to the spec value.
You'd also be smart to check the tightness of the carb hold down bolts and nuts, and the tightness of the intake manifold bolts.
Then you can test for leaks around the carb, when she is running shoot a little carb cleaner around the base of the carb and around the perimeter of the intake manifold. If the motor picks up speed there's your leak..
Good luck, hope it's something easy.
If you don't have a tach you trust they have a low cost shop meter & tach at Harbor Freight for $39, you just put the pickup around the coil wire and it gives you real RPM. Handy. Not a professional meter, but with the use we do it yerselfers put it to, it would be OK.

 

[rinkerthestinker]

Re: 1994 mercruiser 4.3lx stalling problem

i tried to run it without the fuel cap on, and it did the same thing. the tach on the boat says it idles around 750-800, but wont stay running long enough to really warm up(stalls around a min or two). where is the anti syphon valve located at?

 

[NHGuy]

Re: 1994 mercruiser 4.3lx stalling problem

OK if the fuel-cap-loose did nothing you could check to see if there's fuel in the bowl after it shuts down. Have someone do a couple of pumps while looking down the carb. If there is gas, look at the choke, metering and intake leak ideas.
Also is the motor timed right? And are the ignition parts good?
The anti siphon valve on my boat is at the tank outlet, it looks like a little extension that comes out of a 90 degree fitting and has a barb end for the rubber fuel line on the other end. You can remove it by first taking the fuel line off the barb, which can be a pain in the derriere itself. I had to use one of those little 90 degree picks under the hose end to finesse the hose off the barb. Then you get a wrench on the piece coming out of the tank, and another on the anti siphon valve. Don't torque against the tank fitting. It's soft metal.
Then remove the valve and give it a good cleaning out if there's any crud in it.
If you want to really be sure everything is good take off the other end of the fuel line and make sure it's clear by blowing it out. Also check any fuel filters.

 

[rinkerthestinker]

Re: 1994 mercruiser 4.3lx stalling problem

well i took both lines off the tank(vent and fuel intake) blew threw them and didnt seem to have any obstructions. the screen on the fuel line in the tank also appeared clean. i replaced the plugs, fuel filter/water seperator, it has a new carb on it, just put on tues. i looked over the plug wires pretty good they didnt appear worn at all, and the dist cap appears the same. the way it acts just seems to me its running out of fuel, but i have 0 experience working on boats.

 

[Bluewaterhawaii]

Re: 1994 mercruiser 4.3lx stalling problem

When you replaced the carb did you replace it with the same 4 barrel Weber/carter Afb/Edelbrock. After you installed it you should have adjusted the two screws on the front of the carb, one mixture and one idle, and also check your accelerator pump position you should be able to adjust the position of the arm to push more gas through. You're going to have to get both of these adjusted just right. Here's a link for Mikes carburetor that i used to rebuild my 1994 4.3lx carb and get the adjustments right.http://carburetor-blog.com/?page_id=157

Hope this helps