8.1 GiL idle adjustment

[imported_Dan]

Two Volvo questions.

First: I have a set of Volvo 8.1 GiL inboards on my boat serial numbers 4012110666 and 4012110667. They are in my 2004 Carver 396. The starboard one idles at 600 rpm and the port one idles at about 750 to 800 rpm. I backed off the idle stop screw on the port engine but the throttle body butterfly was already seated all the way so it made no difference other than put and air gap between the set screw and the linkage. I could easily increase the starboard engine RPM to match them up but I am not sure if this is the right solution. How do you reduce the idle on one of these engines?

Second: This is my first set of Volvo's. Previous boats were all MerCrusiers. These motors emit more steam than the merc's did. Both engines are running at 130 degrees according to the temp gauges. There are new impellers in both and they steam throughout the season of Lake Michigan water but more prevalent in the cooler water temps of the spring. To the eye they are both putting out a fair amount of water and it is the same flow on both engines. The motors run perfect. The impellers are smaller than the ones I had on my 7.4 mercs and I have been told that Volvo's do steam more.

Any advice on my questions would be appreciated.

Thanks,
Dan

 

[Don S]

Re: 8.1 GiL idle adjustment

I backed off the idle stop screw on the port engine but

NEVER adjust that screw, that is not what it's for. If you know how much you turned it, put it back.
The ECM and the IAC valve control idle rpm, assuming the throttle cable is not holding the throttle open.

Below is how to test the IAC,

 

[imported_Dan]

Re: 8.1 GiL idle adjustment

NEVER adjust that screw, that is not what it's for. If you know how much you turned it, put it back.
The ECM and the IAC valve control idle rpm, assuming the throttle cable is not holding the throttle open.

Below is how to test the IAC,

Don,

Thanks for the quick reply. I did mesure exactly how much I backed off the screw and it is back to where it was. I did disconnect the throttle linkage to make sure is was not part of the problem and there was no difference. What would be the ideal RPM at idle? Any thoughts on the steam?

Thanks again,
Dan

 

[Don S]

Re: 8.1 GiL idle adjustment

Any thoughts on the steam?

Ever run Merc big blocks before? Big blocks do steam more than small blocks.

600 rpm is typical.