Mrs T

Hello OSO,

Hopefully someone out there can help me with this issue. I have a 2003 575 SCI with 88 hours on it that runs great when cold, but tends to hang at 1100 rpms for 2-3 seconds after bliping the throttle. To trouble shoot this, we scanned it, and this is what we found:

Cold--IAC at 60, and drops fast to 35 pulses. No problems there.

As it warms up above 120 degrees, IAC stays at 38, and the idle is perfect at 850 rpms or so. If I blip the throttle to simulate giving it a bit of throttle for docking manuvers, the IAC jumps to 175-190 then falls to 112, 100, 80, 70 then to 35 again. the whole time, it runs great, except for holding the rpms at 1100 or so. The whole time, the TPS is at .54 volts.

What would cause this? Any ideas??? Please advise.

Thank you in advance

Pwrbt33

iTrader: (2)

Thats kind of normal. I have a few boats here on the Bay that do that. Not really been a problem.

John

Steve Zuckerman

Mrs T,
Tell Mr T hi. I haven't seen him in years. What's he been up to?
A. make sure that your throttle cable is adjusted to have enough preload on it so that it is completely closing off the throttle bodies at idle. If there is any slight opening on either unit's venturies, it will idle fast, particularly when hot.
B. the stock ECU idle program can be modified to get rid of this annoying idle characterstic. Is yours stock or modified?
Regards,
Steve

BillR

It is normal for that to happen with those motors. They take a few moments to idle back after bliping the throttle. Annoying, but 100% normal.

kjm5125

I had a similiar problem. All I did was lubricate the linkage with WD 40 and adjust the cable.

JaayTeee

That's how mine act also.

lowfunds

perfectly normal condition. try doing it in your car it usually does the samething.

organizedchaos

Thank you for the feedback everyone. One motor does the high idle thing, and the other one does not. I guess that I should be lucky that both do not do it.