2001 Merc 115 EFI Won't Start with Idle Air Connected

Hpracer

Seaman Apprentice
Joined
Aug 26, 2016
Messages
30
I have had a strange situation with my 2001 Merc 115 EFI. When I recently cleaned out the tiny filter for the high pressure fuel pump (for the fourth time) and restarted the motor I left the connector to the idle air control unplugged because that is the way I found it when I got the motor back from the marina after they did the job the first time. Normally my motor will not start with this connected and I have been living with the high idle point for the last couple of years always thinking that I should look into this but not doing it. Well this time, for the heck of it, I plugged in the connector after it had already started without it, and it started and ran for a few minutes with the muffs on, and the idle actually seemed to be more in the 700 range than the 1100 that it used to be. However, when I went back a day later to start it I couldn't get it to start without disconnecting the connector into the idle air control. In the trouble-shooting part of the manual it says that the result of the sensor not working is that the idle increases. It does not mention that the motor won't start without it.

Questions: Has anyone else had this issue? Does it seem like the air temperature sensor in the silencer is the problem? Is there some way to be sure that the sensor is the problem without spending $150 for a new one?

P.S. There is a cable near the top of the motor above the MAP connector that seems to be a jumper of some kind. It has a male and female connector, is not part of the harness, and the male connector is the same as the one that plugs into the idle air control. On my motor it is not connected to anything. What is it for?
 

Hpracer

Seaman Apprentice
Joined
Aug 26, 2016
Messages
30
This forum is becoming fairly useless. No one with any knowledge of these motors reads these posts and there is no reply after two weeks?
 

GA_Boater

Honorary Moderator Emeritus
Joined
May 24, 2011
Messages
49,038
This forum is becoming fairly useless. No one with any knowledge of these motors reads these posts and there is no reply after two weeks?

What's useless is people complaining that a post gets no response when the poster doesn't even try to bump his own thread.

Unlike you, we are human and can miss a single post from 2 weeks ago. You think you are the only one asking questions?

Free advice from working people and volunteers is not always instantaneous.
 

Hpracer

Seaman Apprentice
Joined
Aug 26, 2016
Messages
30
OK - My bad for complaining, but when I wrote that post exactly 2 people had looked at it and no one responded. Instantaneous is one thing. Two weeks is another. I bumped it by responding to my own post.

Now for the few people that actually are wondering about this I have it figured out. The jumper with the male and female connector is just that - a jumper that allows the connector from the harness to plug into one end and the other end plugs into the idle control. I have no explanation as to why it would or wouldn't start with this connected, but it starts now and idles down to where it is supposed to be.
 
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