Monster S4 916 fires once but will not start
 

Hi, my 916 Monster S4 will fire once but not run. The original fault was no spark switching within ecu. Now have tried a racing ecu and another flashed to disable immobiliser. Have tried a new timing (CPS) sensor. All relays good, wiring all checked for continuity and voltages, sensors checked, switches all checked and connectors for corrosion and continuity. So to sum up, whilst cranking it will fire once and occasionaly will fire again after 1o seconds or so if I continue to crank it. At end of my tether with it!!!

The usual reason for blowing the Coil driver inside the ECU is a fault on its output, usually a dodgy coil. Have the coils been checked or changed

Sounds similar to the fault I had at Anglesey. Eventually backfired and set fire to the air filters :o . Turned out to be the air pressure sensor, the one on the header tank.

However you mention an immobilizer? does it have an alarm because that would be my first suspect.

Neil it uses a 59M ECU with a separate OEM immobiliser. All very similar to a Class A DD bike

Air press sensor on 2001 has no electric connection. Tried stick coils. All points to CPS timing sensor but tried that too. All sensors, wiring checked. Phonic wheel checked. Re;lays checked. New flashed ecu and racing ecu tried. Good battery tried. All switches checked including sidestand etc, When cranking, fires once and if held may fire again after about 19 seconds, Tried turning back wheel in gear with plugs out also gives one spark. Tried pulling CPS out and using iron rod to trigger cps, sparks each time, Pump runs, injectors pulse once like plugs,

Thanks for that for that Kev.

Only thing left for me would be to change the loom for a known working one and then start again from scratch.

Does anyone know if the Ducati-Diag software would throw up any faults that might help...

Just curious, for possible future info...

A quick look found similar problems elsewhere but nothing specific.

Here is a Ducati forum specific search for you to try:

Iconic MegaSearch

As you say, it all points to the Crank Sensor, certainly worth trying another one

Thanks. Tried yet another CPS (timing) sensor, this time a gunuine Bosch one. Same result. It will fire once, occasionally twice. If I continue cranking it may fire again. Set CPS gap correct, tried making it smaller, continuity checked all wiring to ecu and checked all sensors, switches, relays, connectors. Had close look at phonic wheel. Even checked cam belts not broken (getting desperate!). Reseated ecu connectors many times now. Tried jumping with car battery, Tried using seperate battery to crank starter. Checked CPS, ignition and injector wiring for short ccts. Tried disconnecting injectors and then coil stick to see if either dragging it down. Tried taking fuse out on regulator line. Jumped relays, sidestand switch and ignition switch. And cut-out switch. Loosing the will on this one.