Reincarnation of a Rat

[Laitch]

Although you might not yet have completely recovered from Rifa madness, have you cleaned the main ground connection beneath the frame backbone and all terminals attached to it?

[bitsa]

That was one of the first jobs when it followed me home as a basket case, before installing the wiring harnesses. It does act like a bad ground or flaky connection though with how it just "switches" from behave to dung-heap mode, so will take your advice into account and go after the grounds first off (if only to re-confirm good continuity).

One thing I've noticed is, when it's acting up now it's not doing the rich/lean thing just purely dropping lean & if I hold the start button down for start enrichment it actually seems to run fine then.

Also, last night I checked the TPS as it appeared to make no difference & it's not acting quite right. IIRC it's just a pair of switches right? One closed at zero throttle and the other closed at WOT?  Can't find the pinout/test on Drake's site that I recall previously using, but either way it now seems to have flaky "closed" resistance & "open" there's 25meg or so between all pins. Sounds wrong to me so will try and search out the testing for that again & try some diagnostic bodges if it won't clean up.

Cheers 

[bitsa]

OK well, more by bodgery than repair it's running well again. Long & short of it is I made the ECU think the starter button is constantly pressed therefore enriching the mixture.

Thanks in no small part to Laitch (Saint Laitch of Vermont???) I've some more in depth testing to do if/when I see fit but for the moment it lives once more!

[daveson]

I think you're saying that it runs ok, but then when the engine gets warm it goes lean, I guess that might mean about ten minutes after start up. Even if I've interpreted this right, my guess is still unlikely, but it's such a quick and simple thing to check.

This reminds me of a problem I've seen on cars in the past. Start it up and wait for it to go lean, then pop the fuel tank cap open. If the problem then disappears, one possibility is that the fuel filter is lousy, but you replaced that, goodo. Another possibility is that the fuel tank vent is blocked.

[bitsa]

Thanks for the suggestion, fuel pressure is steady hot/cold/rich/lean though. Fuel filter was a brand new, quality item fitted by me when I got the bike & tank was previously de-tarred/resealed & had new pump, lines and isolator. 

Good thought though, appreciate the input. I've seen that on cars also, usually accompanied by a "whoosh" of air being drawn in when opening the cap. 

At this point I'm not sure what I'm saying myself, except for the fact that it currently runs* as well as it's ever done in my ownership & due to other 4-wheeled eye candy occurring I'm pretty well donezo with the thing and may let it go to free up some funds if anyone's daft enough to buy it!

[daveson]

Also, there's a troubleshooting guide at k100 forum/tech page/electrical/troubleshooting the EFI (English) for the fuel injection computer, air flow metre, lots of other sensors, and heaps more.

[bitsa]

Not so much an update today, more like closure for anyone following. The bike is now gone, sold to a guy who wanted it for parts so it's being chopped up and pieced out. Best thing for it if I'm honest, it was super ugly and beat up but lots of usable parts to keep other bricks alive.

Money's going toward a car build we've got going on, not going to be stock but definitely much less ugly and bastardised than the K.

[Laitch]

Not so much an update today, more like closure for anyone following. The bike is now gone . . .