4.3 Mercruiser Stalls when it is given gas in neutral or in gear

[dlewis0714]

So I have a 1993 Sea Ray with 4.3 Mercruiser that sat for about 4 years. so far, I have Rebuilt and cleaned the carb, new gasket its the thick kind., I replaced distributor cap, rotor, camshaft positioning sensor, plugs, wires, starter, lower shift cable, gimble bearing, cleaned fuel tank, also replaced fuel lines and fuel filter with aftermarket 3/8 rubber fuel line and regular in line fuel filter.

So the problem I am having now is that whenever you try to throttle in neutral or in gear it just stalls right out. If I let it warm up in idle then I am able to jam the throttle down and mess with it and I am able to get it to throttle up to higher rpms and it stays there just fine. The problem is just the initial throttling kills it 9 out of 10 times. Anybody got any ideas?

 

[Bondo]

So I have a 1993 Sea Ray with 4.3 Mercruiser that sat for about 4 years. so far, I have Rebuilt and cleaned the carb, new gasket its the thick kind., I replaced distributor cap, rotor, camshaft positioning sensor, plugs, wires, starter, lower shift cable, gimble bearing, cleaned fuel tank, also replaced fuel lines and fuel filter with aftermarket 3/8 rubber fuel line and regular in line fuel filter.

So the problem I am having now is that whenever you try to throttle in neutral or in gear it just stalls right out. If I let it warm up in idle then I am able to jam the throttle down and mess with it and I am able to get it to throttle up to higher rpms and it stays there just fine. The problem is just the initial throttling kills it 9 out of 10 times. Anybody got any ideas?

Ayuh,.... Welcome Aboard,... Go back to the Carb,.... It sounds like the accelerator pump ain't workin',....

 

[flipbro]

Shift interrupter switch. Shift cables need adjusting. Possibly

 

[Bt Doctur]

idle set too lean, no accel pump or pump not working correctly,choke not working or set improperly

 

[joetheis]

My shift cable went bad, it'd die ONLY going into reverse. I din't think it'd go bad forward er reverse??
You can tinker with the adjustments, GREAT info here on how to do it or U Tube.
Measure EVERYTHING all up BEFORE you start, so you can reset it or know where your at. I kept a running record of mine tinkering before I figured I had to replace it. I also lube the cable-that worked for a few weeks!
Sounds like the acc. pump is not pumping.
You can test, open the choke blades, (with the engine off!!), look down the throttle plates and give the throttle a yank!
You should see a steady stream, dribbles or nothing-bad!
The low speed mixture, engine off, crank both in til they just touch, then n\back out the same amount (always turn BOTH screws the same amount).
Warm her up til the choke is off, turn them out til the idle starts to drop,and your set, (I use a vacuum gauge, highest vac is great)!
Your fuel pump could be weak too, check output.
remove the line at the carb. start her up and measure how much fuel you pumping (BE CAREFUL!!).
Joe
As always take any advice I give with a beer er 2!

 

[dlewis0714]

My shift cable went bad, it'd die ONLY going into reverse. I din't think it'd go bad forward er reverse??
You can tinker with the adjustments, GREAT info here on how to do it or U Tube.
Measure EVERYTHING all up BEFORE you start, so you can reset it or know where your at. I kept a running record of mine tinkering before I figured I had to replace it. I also lube the cable-that worked for a few weeks!
Sounds like the acc. pump is not pumping.
You can test, open the choke blades, (with the engine off!!), look down the throttle plates and give the throttle a yank!
You should see a steady stream, dribbles or nothing-bad!
The low speed mixture, engine off, crank both in til they just touch, then n\back out the same amount (always turn BOTH screws the same amount).
Warm her up til the choke is off, turn them out til the idle starts to drop,and your set, (I use a vacuum gauge, highest vac is great)!
Your fuel pump could be weak too, check output.
remove the line at the carb. start her up and measure how much fuel you pumping (BE CAREFUL!!).
Joe
As always take any advice I give with a beer er 2!

Ok I checked the acc pump by leaving choke plate open and yanked the throttle and i saw a steady stream then bubbles. Then I noticed my fuel pump seemed to be going on and off and noticed if i moved the harness for it would go on and off. I rewired the fuel pump and it seems to stay on now.

So as soon as engine is warm and I jam the throttle all the way down in neutral or in gear it will rev up and stay revved at all rpms so I dont think it is the newly replaced shift cable. I had a Mercruiser Mechanic do the gimble bearing and the shift cable.

Could you give me a little more guidance on this statement below. Im not sure I know what your talking about.

The low speed mixture, engine off, crank both in til they just touch, then n\back out the same amount (always turn BOTH screws the same amount).
Warm her up til the choke is off, turn them out til the idle starts to drop,and your set, (I use a vacuum gauge, highest vac is great)!

So the problem really seems to be if I try to throttle slowly it stalls out other than that after it is warm it seems to be ok.

 

[dlewis0714]

idle set too lean, no accel pump or pump not working correctly,choke not working or set improperly

How do you know where to set the choke plate? Is there a factory setting or do you have to move it to each notch and run it? I did what the other guy said to check acc pump and I saw a steady stream and then bubbles....that is good right? Also are we taking in to account that after it is warmed up I am able to jam throttle down and it will catch and rev up just fine?