DF 150 - high idle speed - buzzer warning

[orohde]

I just changed battery. The motor started but the idle speed did not go below 1300rpm. The buzzer started to beep, but not combined with any lamps on the rpm instrument. This case is not described in the owners manual. What could be the reason for the high idle speed and what does the buzzer tell me when it beeps "alone".

The motor has been out in freezing conditions for a couple of weeks. Thats why I changed battery. the capacity was ti low in cold weather.

Its a DF150 year 2007.

[catacom225]

Idle

When the idle exceeds 1000rpm an alarm code sounds [ single beep ]
Adjust air idle screw to 650rpm, then rev engine to over 1000rpm to cancel code

[orohde]

Air idle screw - location

Thanks, now I need to locate the screw. It is not indicated in the owners manual. Is the screw easy to find?

The idle speed has been good the whole season. Any teory on why it came to be so serious so suddently that it now needs some screw adjustments?

[catacom225]

Idle

Remove the front air box and it will be above the air intake

[orohde]

Idle speed to high

Thanks, I will go and try this. I'll be back with a report

[z21832086]

fix it right

do not mess with the idle air screw!...go inspect the white battery sub lead- fuse, condition, and connection to the battery

[orohde]

white battery sub lead

I checked the connection and it looked good. I did not have any instrument to measure conectivity so I tested by disconnecting the lead when the motor was running. It stopped, so I guess this is perhaps not the source of the high idle speed.

I am still reluctant to make any idle screw adjustment because I do not know of any good reason it has been removed from its "proper" position.

What else could lead to a sudden increase in idle speed. Something must have been broken either in connection with the battery change or during the freezing cold conditions.

[catacom225]

High Idle

Orohde
You might try removing thr IAC valve and cleaning the air passage there may be an air flow restriction

[orohde]

The reason for the high idle speed is found

The IAC valve was deformed, like if was hammered. This led to the sitiuation where even when the engine computer ordered full closure on the IAC there was still air available. The amount of air trespassing was high enough to keep the engine running at 1300rpm. I changed the valve, but we still could not get the idle speed below 800rpm, which indicates that the surface (IAC valve seat) on the intake manifold also was distorted. This means I have to buy a new IAC valve stepping motor and a new intake manifold, grrrrrrrrrrr!!!!$$$$$

Now that the reason for high idle speed is identified, I wonder how the valve could be destroyed like this. Any idea folks??

[catacom225]

I the same IAC valve from a Suzuki auto wrecker, and why not see if a machine shop can resurface your manifold or block it flat yourself

[brycer]

not to highjack this thread but i am having the exact same problem with a used 2006 df140 i bought and rigged myself on my lund. It came with no battery cables so i just made some up. It starts and runs fine but is stuck on high idle and keeps beeping. Where is this white wire you speak of and i assume it runs from the battery to the ?. Thanks if anyone can help.

[orohde]

Manifoil repair

I was thinking of doing so, but this is not like grinding in and outlet valves like in a regular engine block, I think. I can not use the IAC valve as the oposit "male" part and by only resurfacing the manifold I suspect it will be out of spec for a new IAC valve. The local Suzuki motor shop could not recommend such procedure either (they sell parts, but still).

Thanks for comments. If someone has a possible explanation for how the fault could appear in the first place, I am very interested. The local Suzuki motor shop could not explain.

[orohde]

To Brycer

My experience with the white lead was that when I removed it, the engine stopped

If we are talking about the same white lead, this should not have anything to do with the high idle rpm. My white lead runs from the battery + into the engine in front, turns to the right lower part and is here entering a one lead plug. I do not know which part in the engine that require this +12V connection.

[orohde]

Idle problem fix

I finally got the parts, a new manifold and a new IAC valve. I did the repair myself with the use of a very impressive service manual by Suzuki. The motor and in particular idle was better than ever. I also discovered that I had sympthons/warnings about this failure earlier last summer season. When I started a warm engine the idle rised quickly and just as quickly it went down and stalled. I had to use the neutral trottle lever in order to avoid stalling. Thanks for your inputs on this tread. Even if i now had warnings I still do not know exactly how tha fault could develop the way it did.

[OceanTrvlr]

I've had this happen on two different DF150s (out of four) in the past couple of years. All four engines have occasionally experienced some kind of detonation in the intake on cold start along with a puff of smoke from the air intake on the cowling. My local Suzuki service shop hasn't heard of this happening to anyone else; they also asked the regional Suzuki service rep who also didn't have any input.

I've had this popping happen on all four of the Suzukis I've had but cannot determine why. I'd like figure it out so I don't have to keep replacing the very expensive intake manifolds and IACs. Any thoughts.

Yes, this is my first post on this forum. Hopefully, I can contribute some knowledge here.

Ethan