2000 SAN GT40 Rough Idle

[SANCasey]

I searched through the old posts, but did not find anything that looks conclusive as to what this might be.

The boat runs fine under way, but at idle it surges and eventually will die. Any thoughts? Could this be just from a dirty fuel filter?

Thanks in advance.

[74green]

Dirty fuel filter may cause it. Check and make sure all the sensors are connected. I believe it was my MAP (manifold air pressure) sensor that came unplugged once and caused a bad idle.

[SANCasey]

Good idea. I will check all the wires in the boat this week. I guess I will order a fuel filter to have just in case. Is there just the one fuel filter in these boats?

[74green]

I just used one of these http://nautiqueparts.com/fuelfilter-pcmfcc.aspx
There is a fuel canister that the filter goes in.

[jjgag60]

boat dies

Check your spark plugs and see if you are running rich. They should be the color of a brown paper bag. Any one of the sensor could be bad causing the ECU to adjust the gas flow. Dont mess with the idle screw on the throtle body. Remember after you change any sensors, disconnect the negative side of the battery for 15 minutes to reset the ECU. If you download the manual from this site, it describes how to trouble shoot each sensor to make sure they are working.

[DanielC]

I would think a dirty fuel filter would not show up at an idle, because of the low fuel demands. Now, it you were losing power at high RPM, at wide open throttle, I would consider the fuel filter one of the first things to check.

[SANCasey]

I am going to work on the boat saturday morning. If it is the idle control valve, does anyone know the model of Ford vehicle that used the same one?

Thanks.

[74green]

i have heard somewhere that the GT-40 uses some parts from a 90's model ford lightning. Hopefully your local auto store can help you match it up with something in their system. if it has a part number on it they could cross ref that number.

[eseybold]

Ford f-150

the Ford F-150 with 5.8 ltr engine (late 90's model) is the same engine -

[SANCasey]

Fixed!

Once I had a chance to look at the engine, it was easy to fix. I had a broken alternator belt.