Running problems.
 

Morning all.

The 888 has been playing up since Popham (1st time ever so cant complain !). Louigi is looking at it and in his usual style has got it in at the drop of a hat for me (until 10.00 Friday night!) but I thought it would be worth sharing the problem here to see if anyone has experienced anything similar - its proving very difficult to trace !

Basically, took, the bike out to the popham meet and noticed that it was 'farting(!)' back through the airbox on the front cylinder when you were pulling away and/or at low revs, it also didnt like to tick over. Upon inspection, you could see the front butterfly 'kicking' up on slight throttle. If I got the bike into second it performed faultlessly. The problem was only on part throttle at low revs.

Took it in to Louigis. After Hans had came in with his race pipe fitted 'sedici and we had a play with the suspension for a while, went back to the task in hand !

We checked/replaced the ecu, chip, fuel pump (which was sounding lazy), fuel filter (and a new tank seal as the old one was a little perished), plugs, plug cap, and fitted a new pair of injectors (2nd hand ones that had just been ultrasonically cleaned and tested).

Also drained the tank and we did find a little bit of water in it which we cleaned out. Rich also had a new ultimap chip so we slotted that in. Finally rich set up the bike up again on the ducati mathesis.

Anyway, rode it bnack he 50 miles or so home and it was A1 (the ultimap seemed to make it run much sharper too !).

Anyway, the kids wanted to go to the wroughton science museum festival up the road so I asked the wife to follow me on the 888 up there to give it a final try.

All seemed to be going well, but I opened her up and after getting up to some speed, it just spluttered, farted and died !

It will fire for a second or two and then just die. And then only if I start it on half throttle - it fires into life revving and then just does away again ?

Im taking it back to riches today but we are nearly out of ideas ! Anyone got any ???!

Cheers
Nat

That sounds very similar to the problems I had with my 888 back in 2000, which was looked at by Neil Spalding at Sigma. The diagnosis was the P8 Computer failing and a £1K bill to get a new one. I traded the bike for my ST4 and never looked back - the next owner was in contact a month or so later and had a lot of trouble with it.

Antonye has a guy who can properly test the ECU for you.

Chris

Think we've ruled the P8 out Chris. Louigi has a spare P8 he uses for diagnostics - that was the second thing we tried and no difference.

About the only thing that's not on your list is the crankshaft position sensor and the RPM sensor. As I recall, the P8 needs both these sensors because it picks up TDC on one pot from the crankshaft sensor as the flywheel comes round, then times how long it takes to get the pulse from the RPM sensor and works out how fast the engine is spinning from that - That's roughly it from memory anyhow.

I went through all that when my T8 was running on the vertical pot only, but in my case swapping the sensors out (and the ECU) didn't make any difference (my T8 is still faulty, but tucked up nice and warm waiting for me to get around to it again).

The other thing, that's next on my list, is to check out the wiring loom. As you know, the various sensor wires feed all the way back along the bike to the ECU under the saddle, then the ignition signals from the ECU go to the ignition amplifiers under the tail, then all the way back to the coils. The signals for the injectors and all the other stuff do this back and forth along the bike as well. I've tried everything else, so it's time to start bussing out the loom to see if I've got a break or a short anywhere - not unlikely with a 16 year old Italian electrical system

Thanks Jools. Will let you know how it goes (will drop the bike back later)

Did you try the TPS?

yep - tps is fine - did a full set up too..

As far as I'm aware, spitting back could be due to a lean mixture and/or timing issue. Intermittent problems are always 'fun' to track down.... You seem to have ruled out the most likely suspects but not the RPM and timing sensors as Jools suggests. Might be worth checking air gaps and swapping them around (or trying alternatives if available) and see what happens?

Keith

Definitely sounds like a firing issue rather than a fuel issue.
Start at the beginning and work your way through: timing > ecu/cdi > coils > leads > plugs