Volvo Penta 5.7 idle adjustment

[32carv]

I have twin 2006 Volvo Penta 5.7gi motors that have EFI. One of my motors idles at 800rpm and one at 600rpm when warmed up. The slower one stalls sometimes when going into reverse.(Always at the worst possible time) Is there a way to adjust the idle? What else could cause this to happen? It has new caps, rotors, and plugs. Both motors run 100% except for this issue.
Jim

 

[alien1952]

The only way is to shorten the linkage at the TPS a turn or two

 

[Sandy]

Isn't idle controlled by the ECM on your (TBI?) injected motor?

It could be caused by a faulty sensor (maybe ECT?) but I'm thinking you might try swapping the Idle Air Control valves to see if the issue follows the parts. If you do that don't give in to curiosity and push or pull the pintle plunger. And let it run a bit while the ECM may be re-learning IAC reaction to it's "commands".

Does that ignition require setting base timing?

And also suggest clean (wipe) out carbon in the throttle body at the throttle plate ( both engines) and be sure the flame arrestor is pretty clean.

Lastly , make sure the helm controls at idle ( especially on the higher idle engine)back off the throttle cables with a little slack so the throttle plate closes and TPS throttle position sensor goes back to 0%.

(FWIW- My blue 5.7L MPI engines have ECM-controlled idle RPM at 640 on warm engines.And base timing and advance are fully controlled by the ECM, not user adjustable , though the critical Cam Retard Angle is adjustable by turning the dist. base with help of a marine scan device to read it. That last may not apply to your TBI engines. )