2003 350 MPI Engine

[NO GIN]

So I am purchasing my buddies 2003 270 FV with a 350 MPI engine. The engine starts well and sounds good at idel and low RPMs. However, when trying to accelerate, she hesitates and wants to shut down. My mechanic says there is 5 different models of this engine and is having a hard time finding the right parts and right troubleshooting for this particular engine. He says the engine actually has 2 fuel pumps and needs a special computer to scan the system to pinpoint exactly what the issue is. Can anyone please help me out? I am a hands on guy and plan on taking over the majority of the mechanicals from here. I hope I am not getting into something that I can't handle. 

[alswagg]

correct this engine has a low pressure and high pressure fuel pump.  Is your mechanic a marine mechanic?  Most all marine mechanics should have a scan tool for Mercruiser and Volvo engines.  Viewing your post's I would believe you have a fuel related issue, as you have not noted any alarms.   Check the hi pressure fuel rail for 40 to 45lbs pressure at all operating rpm.   If the fuel pressure falls when the rpm falls check for restricted fuel line, or clogged filter or worn fuel pump.   Allan

[NO GIN]

correct this engine has a low pressure and high pressure fuel pump.  Is your mechanic a marine mechanic?  Most all marine mechanics should have a scan tool for Mercruiser and Volvo engines.  Viewing your post's I would believe you have a fuel related issue, as you have not noted any alarms.   Check the hi pressure fuel rail for 40 to 45lbs pressure at all operating rpm.   If the fuel pressure falls when the rpm falls check for restricted fuel line, or clogged filter or worn fuel pump.   Allan

Thanks Allan. You are correct we have had no alarms. My mechanic (the original mechanic to the boat so I kept him) is a marine mechanic but does not have the scan tool. He has to bring someone else in to scan it. Will that pinpoint the problem? He did say he thinks it's the fuel pump but wouldn't that make for difficult starts? Thanks.

[alswagg]

A scan tool will not tell you if you have low fuel pressure.  On top of the intake just behind the throttle body, you will find a schrader valve.  This is the connection for a high pressure fuel gauge.   I would start there, along with scanning the engine and viewing the sensors while running.   Allan

[NO GIN]

Ok great. Thanks. I will post results later.

[NO GIN]

They told me that the lift pump is bad. While scanning the engine they pulled the engine hours which are 346 hours. More than I was lead to believe since there is no hour meter. Is that a lot for an '03? What issues/maintenance should I expect seeing as she has these amount of hours?

[alswagg]

below average for hrs, that is only 38.4 hrs per year.  Has all of the bellows been changed?  The gimble brg should have been changed, along with the shift cable.  Engine wise, no problems.   Has the boat been sitting for a while?  If so the fuel probably has went bad and caused the booster pump to over work.  Have they verified the booster pump is the problem?   Remember to change the impellor also.   Allan

[NO GIN]

That was exactly it. The lift pump was bad. They replaced it ($250) and the boat runs great!  Just got back from the first run and have a huge S&*! eating grin on my face!!!   

[raybo3]

Great!!!!!!!!!! I am very happy for you. Good luck with the boat.....