Ducati Sporting Club UK > Model Specific - Discussion, Technical Problems and Help > 998 / 996 / 916 / 748 > Crappy Idle

[Mr Nick]

What is the most likely cause for my 748 not idling until the temp hits about 160? I used to be able to fire it on the frostiest of mornings and not need the fast idle button. Now I need the fast idle button to get it going and then it takes about 15 minutes of riding to get it to thepoint where it won't stall whilst I'm waiting at junctions etc. Once the bike is really warm, it idles without a care in the world. Can't leave it running on fast idle for 20 minutes every morning before I go to work - after all, it's only a bloody 15 minute ride away!

Oh yeah... forgot to say that it had a full service about 3 months ago and is in daily use.

[Edited on 26-5-2004 by Mr Nick]

[TP]

AAARRRGGGHHH NOOOOOOOOOOOO!!!!!!!

160 sounds excessive and maybe I'm jumping the gun a bit here but I'm getting all jittery thinking of you riding your bike without warming it up properly!!

If you haven't already done so please read this article http://www.sigmaperformance.com/rockers.html

Neil from Sigma replaced 8 rockers in mine when I took it to him the week after I bought it last year - it was otherwise mint and the kinda bike that you would think was perfect - just not warmed up properly!

[DJ Tera]

TPS might buggered, or the throttle bodies might need syncing

[Mr Nick]

It generally gets a 5-10 minute warm up before I go - enough to get the needle registering on the gauge. This has been usual for me for the last 18 months of owning the bike and it gets used 7 days a week all year round. Only this week has it started faltering and needing to be run for so long before it'll idle sweetly. Throttle position sensor was replaced about 12 months ago and this feels nothing like the problems that were caused when that rascal went pop.

[rockhopper]

Temp sensor on the ECU gone so the ECU always thinks the motor is hot and never actually does a cold start.

[Mr Nick]

Now that sounds like a possibility... and expensive Is this a big job to check out and repair?

[TP]

Sorry for my panic - I guess I just wanted to make sure you knew because rockers (and the labour in getting to them etc) are expensive!

It sounds like the temp sensor (in my uneducated opinion) but a sensor shouldn't be too expensive. Cornerspeed (Nelly) can help you out.

TP

[Mr Nick]

Well, having had a look through the trusty old Haynes manual, it looks simple enough to test so I'll get my pan of water out and and give the swine a good ol' boilin' .

Thanks for the pointers

[ziggi]

That's 160F right not 160C. Which would be about right, around 50C. I've always been told that a lower tick-over is good (unless you're racing).

I suspect all is ok - annoying - but try just turning the tick-over advance screw on the right side of the bike just a little more to increase the tickover slightly. Cant remember where it is. They tend to set the tickover low after a service. Mine ticks over about 1250 rpm and fast idles about 1500rpm but is at the point where it sometimes stalls when cold. Maybe not as bad as you mentioned but still needs to be warm to idle completely right.

[Edited on 27-5-2004 by ziggi]

[Mr Nick]

Well, I finally got round to testing the sensor and all the readings I got were within the Haynes specified ranges. The plugs look in good condition and the air filters are clean. I tried upping the idle from it's usual 1000 at cold to 1250 but it still stalls after about 25-30 seconds. Once the temp hits the 160 mark, then it bobbles along at a steady 1000 without a hiccup.

Any more ideas what I can look at?