df 250 eating IAC valves

[Moonlighter]

I doubt if anyone is going to repeat again the suggestions made earlier for you, so it will be up to you to dig back yourself.

I would suggest that you go back to the original thread you started on this issue, read the responses, and you will find the specific things to check are already set out there by several of us.

Also, go back to the original thread you started on the same topic on THT and take note of the advice from two very experienced Suzuki dealers there.

The general consensus, both here and on THT, is that the problem is in the electrical system.

Try to put the IAC valves out of your mind. They are most likely the symptoms of the real problem. Solve the real problem and the IAC valves will sort themselves.

Plan B is to find a really good Suzuki mechanic in your area and take it to them for fixing.

[straycatboat]

I don't have a really good Suzuki mechanic near by, so I am on my own .
I will go back and do the suggestions methodically and try to figure it out.

[RussArran]

Just a thought: the times I've had to replace IAC valves were all following backfiring incidents; it might be worth checking the timing/fuel side of the engine.

The IAC units seem to be quite sensitive to a sudden blast from the cylinders after which they lock up; it only takes one "pop" from a cylinder to do this...

[straycatboat]

I haven't heard a backfire. Can you hear it?

[RussArran]

Not from where I'm sitting...

Seriously though, could be anything from a really obvious bang to a loudish "phut" which you might miss if there are other things happening.

[Moonlighter]

Can I suggest maintaining some focus here, rather than tilting at windmills? Jumping from one solution to another without completing an investigation or thinking about the possibility of that thing being the cause is really not going to help.

For instance, if you think about it, what are the chances of both engines backfiring at almost the same moment resulting in both engines having the same IAC problem?

And, especially when the symptoms attributed to be the "IAC failure" are inconsistent - ie they don't happen all the time. Does anyone know of an intermittent IAC failure?? Is anyone else reporting IAC failures every 40-50 hours?

No. Of course not.

So what does that tell you?

It says that multiple simultaneous IAC failures are extremely unlikely, almost impossible.

Those symptoms all point to something electrical that affects both motors at the same time, don't you think? what do both engines have in common? Answer: the boat they are bolted to, including its electrical system.

Stay focussed.