1991 Mariah PCM 351 stalls after a few seconds

[joe Schnur]

Replaced fuel filter fuel pump still runs and roughens up and stalls. Please give me some where to look. Thinking about looking at replacing the fuel lines next .

No leaks pressurizedk tank and no leaks.

Don't have access to no ethanol fuel. Could this be causing an issue adding cd2 lead substitute.

Thanks in advance

[Wulphie]

Check the easy stuff first. Look down the throat of the carb, if the floats are stuck it will be leaking fuel and flooding the engine. Very common with the Holley carbs.

[joe Schnur]

Doesn't seem to be flooding seems to be starving

[Wulphie]

That is easy to verify. Is the accelerator pump squirting fuel?

[chris young]

Is this an idle only problem? Will the motor run at higher RPM?

[NorCalPR]

Might sound simple, but I had a buddies boat that the fuel screws backed out and were 4 turns out.

After adjusting, it ran like a champ.

Worth double checking. Turn the screws in and count the turns. Back it up the same amount if around 2

Both screws should be the same

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[joe Schnur]

Will try the screws it is not just an idle issue I rev the engine to keep it running it eventually dies. Yes initially the pump will squirt fuel.

[Wulphie]

Will try the screws it is not just an idle issue I rev the engine to keep it running it eventually dies. Yes initially the pump will squirt fuel.

If the accelerator pump will only squirt fuel once check that the linkage is following the cam properly. It is common for the shaft to get corroded and the linkage does not follow properly. The lever will stay in the depressed position. If the linkage is functioning properly you need to get into the guts of the pump. If that all checks out then you most likely have a fuel supply issue.

[joe Schnur]

Accelerator pump always works. Cut 1.5 inches off each end of the hose . Blew out the check valve on the tank retightened everything engine runs rough probably due to the hose being stretched over the edges of the tank.

Two more pieces of info
1 The rpm gage bouncing around a bit may have been due to the rough run but seemed a bit off from what I expected the RPGs to be.

2 The spring in the valve on the tank seemed a bit stiff.

3 The fuel light is on but there is plenty of fuel in the tank?

Ok wise fellow users help me get back on the water

[joe Schnur]

Still not working

Pulling and rebuilding carb