Perfectly running F4i suddenly Cranking but not Starting
 

Hey fellow F4i enthusiasts ...

Firstly, I've searched and searched this forum for previous posts regarding the problem I'm having, but no luck ....

I need some experienced advice on why my previously perfect running 2002 F4i (with 42,000kms / 26,000miles) refuses to start - the fuel pump primes, the starter motor cranks, but the engine refuses to catch - I can't tell if it's because there is no fuel being supplied by the injectors, or there is simply no spark. I can smell a bit of fuel from the exhaust when it cranks, but not plenty.

Background: I installed a GI Pro X gear indicator .... prior to this, the bike ran fine.

What the GI Pro X installation involved:

(i) removing the headlamp fairing housing, in doing so disconnecting the wire harness to the light AND the bank angle sensor, to connect the GI Pro X indicator.

(ii) disconnecting the speed sensor connector (at the gearbox) to connect the GI Pro X harness.

(iii) splicing into the RPM wire (yellow with red stripe) of the ECU to connect the GI Pro X RPM-detection wire.

All 3 of the GI Pro X tests (after I reconnected the headlamp housing and wire harness to the bank angle sensor etc) tested FINE ie. the GI Pro X was connected correctly.

The next stage involved programming the GI Pro X .... this is where it all went downhill, because the bike needs to be started and idled for the GI Pro X to be programmed.

As I mentioned, despite being VERY careful with removing the headlight housing, removing the seat (to access the ECU) and lifting the fuel tank (to access the speed sensor connector) - all three things I've done many times before and re-installed with no problems - I was very surprised the bike suddenly wouldn't start.

** I did initially disconnect an incorrect 3-pole connector (to the reserve fuel tank sensor) instead of the speed sensor connector ... following advice from Healtech I corrected this error ie. reconnected the fuel tank sensor **

Some things I've done to troubleshoot why the bike is cranking but not starting:

- bypassed the bank angle sensor to see if it was the problem - NO LUCK ... the fuel pump still priming and starter motor cranking, but engine not catching.

- disconnected the GI Pro X's RPM-detection wire from the ECU - NO LUCK ... same problem.

- as per Healtech (GI Pro X's supplier, excellent response btw) advice, disconnected the GI Pro X indicator - NO LUCK ... same problem.

- disconnected and re-connected MAP sensor connection in case I knocked it out ... connection seems OK there.

- disconnected and re-connected sensor on top of the airbox (can't remember this sensor name) ... connection seems OK there.

- checked and checked for any pinched or disconnected hoses from the bottom of fuel tank - can't see anything amiss.

- I even tried to push start the bike, but the engine didn't even splutter or tried to fire up ... almost as if NOTHING was happening ie. no fuel or no spark or both (I've successfully push started this bike many times before when I had a dead battery).

I'm tearing my hair out now ... what else could it be? The chip in my ignition key suddenly no longer working with the HISS system? The rectifier? Fuel pump relay? Or shock horror, the ECU itself playing up?

I have a service manual, so if anyone could suggest what else I can troubleshoot, I'd greatly appreciate it ....

This problem really stumps me, because the GI Pro X installation seems to have been a fairly straightforward thing; can't imagine it disrupting the bike in such a manner.

Oh, finally, no the FI light is NOT blinking an error code when the ignition is on ie. it is no different to before when the bike was running fine.

HELP .... :icon_deadhorse:

Fuses? Sounds like an electrical issue. Dot your i's cross your t's. Go buck wild with that multimeter. That's what i'd be doing.

Good luck!

Oh, I had checked all the fuses, or at least the main box anyway - they were OK - I'm not aware of more fuses located elsewhere? But thanks Dragonima, I'll check the fuses again ...

Check your spark plugs. A similar situation happen to me my bike ran fine one day then the next my headlights didn't work but everything else worked then the next day the bike wouldn't crank it would prime and the starter would run but the motor wouldnt turn over and push starting didn't work either so I took it to a shop and the plugs were dead and some aftermarket bulbs had fried the headlight relay and everything was fine after new plugs and a new headlight relay

I'll definitely look at the spark plugs eventually, but for now the headlights are fine, which tells me the headlight relay is OK.