Need help with fuel injected KTM motor

[Tom-UK]

Hi guys
I am on the race team at my college and we are using a 1 cylinder SOHC 450 exc engine off a KTM endure. We have converted this one to fuel injection and it has run before, but at the moment it won't start. I know this is a forum for quads but I was hoping some of the gurus might have some ideas on our problem.

We're using a 'mini squirt' ECU and everything works independently spark, cranks sensor, injector, lambda, TPS. It's got compression and the valves are in the right place I checked all of this. It runs wasted spark since it only has a crank sensor. When we fire it the fuel seems to pool for a bit in the intake boot and then combusts in the plenum! We've tried loads of different spark advance/retard and still pretty much the same. We've also changed the fuel quantity and this just changes the degree of how long it takes to catch fire in the plenum. We don't have a base map since the fools before us never saved one.

Any ideas on what could be the problem? I wondered if the plenum/intake boot was leaking so there wasn't a good seal

Thanks for any response

 

[Gen1Pat]

The fuel shouldn't pool. It should spray because it needs to atomize.

 

[jeffsyfm350x]

Sounds like the injector or mini squirt isn't spraying it for enough in the port. I'm assuming there's a fuel pump of some sort is there enough pressure? Is the injector clogged or out of position?

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[Tom-UK]

There's 3 bar of fuel pressure. I am under the impression that intake boot is leaking / not sealing right, could that also be a cause if he fuel atomising properly? I know when we have leaks on the quads intakes it's an absolute biatch to start