2013 DF 140A Wont start

[Ed8029]

I am having a problem getting my engine to start without giving it a lot of throttle. As soon as I back off the throttle it shuts down. Doesn't appear to be throwing any codes.
Runs fine at high idle rpm, no skipping just will not run at normal idle rpm.

[artdf175]

start with the IAC valve
this valve is used to regulate the RPM
and what is known as the dash pot effect when pulling back from a higher rpm to idle
Art

[Ed8029]

Thanks for the help, I checked the coil on the IAC valve and it showed to be shorted. Got one ordered yesterday. Will post update once I get it installed.

[Ed8029]

I replaced IAC valve and had to adjust idle set screw quite a bit. Had to rev in neutral to get it to crank. Held it to 1000rpm ran setscrew in until RPM’s increased. Returned throttle to neutral position and set to around 750-800. Is this normal to have to do this when you replace this valve. When does this valve actually open to let outside air in.

[artdf175]

did you follow the directions from the service manual?
there is a sequence of things that need to be followed
you can find a online free version of the service manual that will help walk you through the steps but highly recommend getting a copy of the book
this web site parts dept has manuals
Art

look at the ‘sticky’ for ‘service manuals’

[Ed8029]

did you follow the directions from the service manual?
there is a sequence of things that need to be followed
you can find a online free version of the service manual that will help walk you through the steps but highly recommend getting a copy of the book
this web site parts dept has manuals
Art

look at the ‘sticky’ for ‘service manuals’

artdf175, I have a 2013 model and there is no setup for the IAC to follow like the previous models. I downloaded the manual. The valve I replaced was shorted so I'm guessing it killed that part of the ECU which sends voltage to open the IAC. I checked resistance at the plug on ECU and read 10.5 ohms. I know my connection to the IAC is good. The valve never opens and I have no codes present that I know of.
Engine is still under warranty. I'm going to take to dealer today. I will post findings on what fix is when I get it back. Thanks for your input.

1G-10 Fuel System:

IAC Valve Control Mode

Before started:

The IAC valve is always closed (0% duty) when engine is not running. (Ignition switch “OFF”).

When cranking:

The IAC valve is controlled to operate at 100% duty.

After start (fast-idle function):

The IAC valve is controlled to operate at approx. 40 – 100% duty until the timer, (set according to cylinder temperature

at cranking) expires.

Then the duty gradually decreases until the engine rpm slows to the preset idle speed.

When idling / trolling:

The IAC valve is controlled so that the engine speed is stable at the idling/trolling speed specified.

During this period, the IAC valve has a duty cycle of approx. 40 – 50%, but will vary slightly as idling/trolling conditions

change.

When running (normal operation):

The IAC valve is controlled to operate at a 40 – 100% duty, dependent on current engine operating conditions.

When decelerating (dash-pot effect):

When the throttle valve is suddenly returned to fully closed, and the throttle position sensor signal changes to “fully

closed”, the IAC valve is controlled to gradually return to an idle/troll operating position to prevent engine stalling or

unstable running.

IAC Valve Removal and Installation

CENDG2111306014

Removal

1) Remove the air intake silencer case.

Refer to “Air Intake Silencer Case Removal and

Installation” in Section 1D (Page 1D-3).

2) Disconnect IAC valve lead wire connector at IAC

valve (1).

3) Remove bolts (2) and IAC valve.

Installation

Installation is reverse order of removal.

• Install IAC valve, then tighten mounting bolts securely.

• Connect IAC valve lead wire connector to IAC valve.

• Install the air intake silencer case.

Refer to “Air Intake Silencer Case Removal and

Installation” in Section 1D (Page 1D-3).

IAC Valve Inspection

CENDG2111306015

1) Remove the air intake silencer case.

Refer to “Air Intake Silencer Case Removal and

Installation” in Section 1D (Page 1D-3).

2) Disconnect connector from IAC valve.

3) Check IAC resistance.

[artdf175]

there should be a section on adjusting thidle speed
there is a specific sequence to follow
Art

[Ed8029]

My boat is still in the shop. They can’t figure it out either, so they contacted Suzuki and they are basically sending all new electronics. I’m guessing this was a problem that was found in the past with this year model.

[Chowder]

Did you ever figure out the problem I have 2 115s with the same problem.

[Ed8029]

They replaced ecu, throttle position sensor and housing all under warranty. Starts fine now

[artdf175]

good feed back
glad you are back and running