Fuel pump issues

[LadyAnya]

Hello, i tried starting my Volvo Penta 5.7L and I don't think the fuel pump is working correctly. I removed the pump and checked the diaphragm and its ok. Put it back on and I can get fuel in the line but nothing moves passed the pump to the carb. What could this be?

Also, whats the name of the rod that pushes down on the mechanical fuel pumps?

 

[rodbolt]

Re: Fuel pump issues

its called, a fuel pump push rod.
easiest way to reinstall the pump on the SBC engines is to rotate the engine until the camshaft lobe that drives the rod is at the low spot,rod fully inserted. grease the rod before inserting it and it usually stays.
if its hot and the grease wont hold there is a 9/16ths headed 3/8X16 bolt just below and to the stbd side of the water pump,that hole is threaded all the way into the rod bore.
you can use a bolt with at least 2" of thread to lightly lock the rod in place.
DO NOT forget to remove the bolt once the pump is in place.

 

[LadyAnya]

Re: Fuel pump issues

I just reinstalled the push rod and pump, however there is still no fuel being pushed in the carb. The "out" line on the carb is dry. What could this be?

 

[rodbolt]

Re: Fuel pump issues

could be nothing in the IN line, could be an air leak on the suction side, could be ya missed the rod with the pump actuating arm, could be defective check valves in the pump.
its a pretty simple pump.

 

[EddiePetty]

Re: Fuel pump issues

...there are two check valves internal of the pump...one or both are not seating properly.

 

[LadyAnya]

Re: Fuel pump issues

I am fairly sure the rod is in correctly. Does this mean I need a new fuel pump?

 

[EddiePetty]

Re: Fuel pump issues

....with the fuel pump bolted to the engine, disconnect both the suction and discharge hoses. Gather together the required fittings and install a vacuum/pressure guage on the suction side, crank the engine and watch the gauge....any vacuum should do but 3-6" would be nice. Re-arrange the guage to the discharge side and again crank the engine......5-7 lbs. would be about normal. Failure to reach either/or of these values warrants pump replacement.