idle issue

[megbert]

I have a 1997 Voyager 320 with twin 350 Crusaders at about 870 hours each, twice this year, upon starting, port engine started at 1300 rpm and would not come down, while starboard started and immediately reduced to 600 RPM. In one case was at fuel dock, I know I approached dock at 600 rpm and did not touch throttle prior to restart, telling me its not a throttle position issue. This time ran the boat when out of speed zone to cruising speed for 10 minutes, reduce speed, and again would not go below 1300, Anchored for 5 hours, then when restarted came right back to 600 rpm with starboard engine. Marina wont do anything if it doesn't occur when they are on the boat, Would really like this fixed as docking or maneuvering in an anchorage with one engine at 1300, the other at even 1000, setting aside damaging the transmission, poses a challenge to maneuver.

thoughts?

[km1125]

The fuel dock one is a weird one. The other one could be explained if your mechanical advance on the distributors is corroded. It will stick at a higher advance which will cause a higher idle until it 'unsticks' and drops down to the base timing. I guess it's possible that when the engine stopped at the fuel dock some lash in the system could have hit the distributor shaft just right and got that mechanism to stick.

Easy enough to check. Pull the caps off the distributors and use your hand to manually advance the rotor. You should be twisting against a spring and it should snap back. You could also check with a timing light by revving the engine while watching the advance go up and down.

how did you work around the issue when it happened at the fuel dock?

[Viper]

Ya does sound like a sticking advance, easy enough to check before moving on to something else. Would help to know the engine model.

[megbert]

regarding the fuel dock, I had the wind pushing me off the dock and waited until clear and use only starboard engine. Eventually I pushed port into gear, despite a transmission clunk. Ran until anchorage and stopped engine. Then 5 hours later it started no issue.

What are thoughts on idle control valve or throttle position sensor?

[Viper]

Source of the post.... What are thoughts on idle control valve or throttle position sensor?

This is where the engine model helps. The good thing is that you have two engines and can swap one part at a time and see if the problem follows the part.

[stanboyd89]

Is that engine fuel injected?

[stanboyd89]

If so, is it throttle body or sequential injection?

[g36]

he mentioned he has crusaders so for 1997 its xli throttle body injection

[SeattleMatt]

I have the same boat and setup, the throttle cables stick a little and may need some adjustment.

[mjk1040]

Intake Air Control (IAC) valves need to be replaced if it's TBI! You can try cleaning them and the throttle bodies. These set the idle speed.