No Accelleration under load

[Pelican Paul]

Hi, I have a 2003 Larson 254 Cabrio with a 5.7 GL Volvo Penta engine. We bought the boat last summer and it had had little use over the last two years. It had a bit of trouble starting last season due to old fuel but I ran that out and had it winterized so that it started fine this season. Half way through July it would not start so the authorized mechanic changed the starter and the distributor cap as well as the spark plugs. Everything was working well, then on day while going along at around 15 knots we noticed a definite small shudder and the boat would not accelerate over 2400 rpms. With full throttle down it will go no faster than 10. We took it to the mechanic right away and checked the prop, filled the tank up with marine gas and then cleaned the air filter.They put the boat through the diagnostics and came up with the reccommendation that the accellerator pump should be changed. It was put on order with Volvo penta and finally installed this Friday but the problem still exists. They are going to check with them this Tuesday . I have been reading that a lot of people have acceleration problems. If it is not the fuel pump what else should I have them check. I have heard suggestions of vapour lock and timing adjustments. Surely this is a fixable problem.

Has anyone had this problem and found a solution to It yet. We would love to know.

Thanks

Paul

 

[Maclin]

Re: No Accelleration under load

There will not be just one root cause affecting all the different boats with acceleration problems you are reading about here. Some boats are fuel injected, some are just old and have not had good service, some have old fuel, and some symptoms are just plain not reported correctly. I recommend you just stick with the authorized mechanic, they told you that they could get more help with your specific problem after the holiday. If you go back with a bunch of non-applicable advice for them it will only slow down their process.

Did they change the accelerator pump in the carburetor? Or the fuel pump that feeds the carburetor? Both are referred to in your post in a way that makes it read like they are the same thing, and they are very different components. If indeed they have been confused as being the same component then an authorized mechanic is the best bet.

One thing you can do is look in you operator's manual and see if there is a "limp home" mode, or any other applicable symptoms noted in the trouble shooting guide there. If you do not have a manual then work on getting one. In the meantime, if no manual, let the authorized service center work on the problem.

 

[Pelican Paul]

Re: No Accelleration under load

It is fuel injected . The part that they changed was the part that was suggested in the manual as a trouble shooting cause for no acceleration. I did not point it out to them but it would make sense that they changed it. They are currently working with Volvo Penta to check off all of the possible problems. It is very frustrating for them as well as me as they are the major marina in a small Lake Erie town and I believe sincerely want to make this work. I was just hoping that someone had had a similar issue that they had addressed. I have heard everything from bad fuel to vapor lock to hoses plugged from everyone else. Thanks for your input.

 

[Pelican Paul]

Re: No Accelleration under load

Hi,

It seems that two of the four fuel injectors are plugged so we are having them changed. We will see if this solves the problems.

This would make sense as this boat had not been used much for the past two summers. It was in immaculate condition with all receipts and hours logged but likely all of this stems from fuel sitting around. At end of our season (October) we will drain the remaining fuel before winterizing and clean out the tank.

Thanks again for your help.

 

[SouthBay]

Re: No Accelleration under load

The 5.7 uses Bosch injectors. IMO send them out to get serviced. They clean up real nice.