Volva penta 7.4GI PEFS

[Ryanformula31pc]

Hello gang. I have a 2001 Formula 31PC with 7.4GI PEFS Volvo Penta’s. My port engine is starting really rough if at all. I have replaced the separator which had water in it. I got the water out of the tank then added new fuel, dry gas and new filter. Now if the engine starts it’s sucking air and will not throttle up It either stalls or drops the RPMs. I have swamped out my IAC valve and swapped the gas line to the starboard tank and no change. I was thinking the fuel pump but 1 out of 15ish times the engine runs fine and throttles up fine. Any thoughts? Thank you Ryan

 

[kenny nunez]

Get a magnet and check if your fuel injector rail will attract the magnet. If it does there is a good chance that the inside of the rail is rusted and flakes are getting into the injectors.
If the magnet does not attract then the rail is stainless.

 

[Ryanformula31pc]

Thank you Kenny. I put a pressure gauge on the fuel pump and maxed out at 30PSI and would drop under load. New pump on it’s way.

 

[jtm3]

I know it is after the fact, and only becuase I just spent $1300 on a new fuel pump on my 7.4 Gi PEFS...

But this website has some really interesting info/videos on V/P fuel pumps - https://mancavemechanic.com/

Thalasso on the THT posted about it - sent his fuel pump to him and he shared the diagnosis on that board - of course he is with out his boat for 2 weeks during the summer, but saved some significant $$.

 

[Ryanformula31pc]

Thanks I have watched a lot of mancavemechicanics you tube videos. I going to send him my other fuel pump to have it cleaned out.