Sneeze at idle

[Blown Up]

What can cause a sneeze at idle?
i have twin 1998 merc300's. When I idle the motors all the way back on the throttle while in gear the motors will "sneeze" and want to die every once in a while. In neutral they never do it. They idle in gear around 500-600rpm. I can bump the idle up with the throttles to around 900-1000 (tel:900-1000) and they never do it. Changed out reeds to Chris Carson reeds and still does it. Everything checks out fine. Just a little annoying at times so trying to figure out what else I should check if anything?

[outasite]

Mite be just a tad lean on the idle.Im a carb guy,so not sure how to richen it up.what is the timeing at idle?

[Blown Up]

I have not checked the timing. I am not sure what it is supposed to be at idle? Being efi, I so not know of a way to bump up the idle in gear?

[Euroski]

Check your TPS voltage adjustment. May need to raise the voltage if on the low side of spec.

[outasite]

Like I said I'm a carb guy,know a little about 2.5 s injection but don't know squat on the 3.0.Hopefully some of the Guys that really know will jump in with some ideas.If they have a TPS that is adjustable, a very slight bump .010 of a volt may help.But any adjustment would need to be done with a factory box.

[njj502]

Check the tps setting. Here is a way to do it with a meter u just need to know the spec. The harness is at the bottom.

http://www.screamandfly.com/showthread.php?237707-Early-225-3L-looses-RPM