Adjust Idle 4.3

[gh78]

Hi

Anyone know how to adjust idle at my 99 4.3 efi engine.?
Runs at 900 rpm.

Norway

 

[ErieRon]

Re: Adjust Idle 4.3

Heres a link to your factory service manual;

http://www.4shared.com/file/137279896/3ce4f06b/Service_Manual_25.html

Pretty sure normal idle rpm is 600-750 rpm. Check out section 5 in the manual. It covers both carbs.

 

[Don S]

Re: Adjust Idle 4.3

Do you have a Volvo or Mercruiser 4.3? TBI or MPI?

There isn't an idle adjustment on EFI engines, one thing you can check, is to disconnect the throttle cable at the engine and see if the engine will then idle down to 650. If it does, you just need to adjust the cable end to allow it to go all the way to idle.

 

[gh78]

Re: Adjust Idle 4.3

It`s a mercruiser 4.3 EFI.

 

[havasuboatman]

Re: Adjust Idle 4.3

Is it idling at 900 RPMs in the water, or on the trailer? Always read your idle when the boat is in the water.
Your EFI can't be adjusted. Follow Dons advice, check your throttle cable. Make sure it's not preloading. If thats okay, you may have a problem with your IAC (Idle air control) system.

 

[gh78]

Re: Adjust Idle 4.3

Hi

900 rpm at sea..
Cabel checked, doesen`t cause the problem..

?

 

[Fun Times]

Re: Adjust Idle 4.3

Hi

900 rpm at sea..
Cabel checked, doesen`t cause the problem..

?

Then more then likely You have a problem with the engines EFI system some place, And you can not just adjust it out like a carb in most cases. But first you need to make sure your rpm gauge is reading right, They do go out of range from time to time.

 

[JustJason]

Re: Adjust Idle 4.3

But first you need to make sure your rpm gauge is reading right

agreed... boat tachs are notorious for not being accurate.
You need to check it with a known good shop tach.
Other than that, your going to have to either drop the boat off at a shop or pony up $400 for a scan tool that will allow you to see what the sensors on the motor are actually doing.