Weird Suzuki Df 250 starting problem, Help!

[straycatboat]

I have a pair of 2008 Df250Suzuki's and both of them when cold, will start up at high idle and immediately shut down.
If I raise the lever to increase is idle before I start them ( like 1200 RPM's) and let them warm up a bit, about 130 degrees on gauge, then I can bring the idle back down and they function perfectly all day.
No codes.
Also some times when I abruptly bring them from running speed to idle quickly, one or both will stall ( like a dashpot issue), but will start right up and idle at 650.
Any ideas? weird

[Harper]

Read this thread... http://www.suzukioutboardforum.com/s...odd-start.html

[straycatboat]

I checked this first and it seems connected correctly, been this way since new in 2009. This is a new issue, as they die when cold , but start properly when hot the rest of the day. I would think if this white wire was not connected or corroded I would have this problem everytime I started them???

[Harper]

I haven't read the thread in awhile, but I'm pretty sure, if you read the whole thing you'll find that my problem was not the white wire, it was low battery charge. Outboards are not as efficient in fully charging batteries as your typical automobile alternator, and I find it to be of benefit to put them on a charger after each week-long outing, right after cleaning the boat before it's put away.

A bad white wire can cause the same problem, but it's not the only cause. The lack of problems at higher temperature could also indicate something electrical, the heat drying a component to the point where it is less likely to short by condensation or any of a number of factors. With the lack of codes, I'd still be considering electrical connections. Stranger things have happened.

[straycatboat]

The white wire has been checked and its connected to battery switch and tight , clean connection.
How can I check the IAC valve to f see if its functioning.?

[Harper]

I give up.........

[Moonlighter]

The white wire has been checked and its connected to battery switch and tight , clean connection.
How can I check the IAC valve to f see if its functioning.?

It seems that you are not willing to listen here, or on THT where two reputable Suzuki dealers have also advised you the same thing - electrical/voltage issue is the problem.

So, one last try: You need to go thru the wiring harness and batteries and somewhere in there, you will find the problem. Have you checked the white wire continuity, for example - the connections may be OK but the wire may be internally corroded. On some boats there is also a join in the harness on this wire and it can be hidden, and corrosion in there has been found by several people to be the problem. A tiny pinch or crack in a wire somewhere, water gets in..... Same applies for you main battery cables, apart from the connections, check the condition and conductivity of the cables themselves.

If the IAC valve had failed, it would be failed all the time. You would be getting high idling all the time.

[straycatboat]

I will run a new jumper wire from the battery to the connection in the electrical holder, This should eliminate any bad wiring issues, I will see if this works, Looks like my only option now.
Thanks guys, will advise how this goes!

[redlowrey]

You don't need to run a wire just do some voltage drop tests with a multimeter. The first one you need to do is measure the voltage drop on crank at the batteries and see what they drop down to, assuming you are starting on both batteries. When cranking if the voltage drops to nine volts or less it will create all sorts of problems with your electronics, in an automotive situation the cars computer has built in software to to allow for voltage drop but not in boats. Have you ever looked under the bonnet of a Suzuki car and see this tiny little battery and leads, and the same size engine in a boat has two massive batteries that's because they don't want the cranking voltage to drop below ten volts. Another thing, running around with the warm up lever on will make the engines stall when you pull the throttle back, Because the closed throttle switch is not working. The closed throttle position switch is activated when you pull the throttle back, the ecu see's the switch closed and will advance the timimg and the iac will bypass more air so the engine doe's not stall dash pot effect. I think your problem is only voltage drop somewhere and should be easy to find.

[Moonlighter]

He has already bought a couple of IAC valves..... (THT).

I give up too.

[straycatboat]

So like I said , I would keep you posted on the outcome.
I would like to thank every one that helped in resolving this issue.
The 2- IAC valves came in today and I installed them in 15 minutes.
This solved the idling problem.
These forums ( and the people in them ) are a wealth of knowledge for the layman.
Thanks again.
Straycat

[redlowrey]

So like I said , I would keep you posted on the outcome.
I would like to thank every one that helped in resolving this issue.
The 2- IAC valves came in today and I installed them in 15 minutes.
This solved the idling problem.
These forums ( and the people in them ) are a wealth of knowledge for the layman.
Thanks again.
Straycat

More like when you disconnected the batteries and hooked them back or charged them that you fixed the voltage drop problem, mate your not going to tell me two engines, two identical problems at the same time two crook iac valves, I would put my balls on line to say if you put the old iac valves back on it would be fine.

[Harper]

More like when you disconnected the batteries and hooked them back or charged them that you fixed the voltage drop problem, mate your not going to tell me two engines, two identical problems at the same time two crook iac valves, I would put my balls on line to say if you put the old iac valves back on it would be fine.

Precisely! .........so, now we wait to see how long it takes for the problem to resurface with the new IACs.......

Well, I wish you luck, straycat.

[straycatboat]

Update: 4 fishing trips = 33 running hours.... IAC's still working.
Starting problem seems to be resolved so far.

[straycatboat]

Ok,
50 hours running time since I changed the suzuki IAC valves with new (Ebay aftermarket units ), Now one of these have failed again , so I replaced it with another and the problem is fixed again.
So why are these engine eating the IAC valves.
Is it because they are not genuine Suzuki parts.
I'm baffled?