'58 plate Nevada Classic ie. Jerky slow running- any fix??

Technical Small Block V Twins (not new V7s)
61

Hi David,

Disconnected the lambda sensor, and it made a big difference. Much better at low revs and when cold. Only problem is, as you experienced, the EFI light came on after a few miles. Anyway, for the low miles I do I can probably put up with that, might have to reconnect for MOT I guess. Might even try the Finebau device again now that I’ve got the basics into better shape. Progress at least!

Cheers

Peter

62

I would throw the Finebau away!

63

I have just contacted Mark Bayley and he says the only way to not have the ECU light on is to disable the lamda probe in the map.
I had hoped to be able to tell you that you can just short across some wires!!!
D

64

Thanks very much for the advice and the research with Mark. My reasoning was that if the Finebau cuts out or alters the lambda signal then I might achieve the same result with it as disconnection. Shorting out wires is my sort of electronics… pity it won’t work!. Anyway if I I can ignore the light I’ll leave it as it is. A much better ride all round.

Cheers

Peter

65

The Finebau I have cheats the ECU by telling it the air temperature is lower than it really is so the ECU runs the bike rich to avoid the lean running that causes the problem.

66

Interesting. I’ve seen reference to inserting a diode in the lead from the Lambda to decrease the current received by the ECU, and that that was basically what the Finebau does. All above my pay grade I fear…!

67

I think there were two different systems used by Finebau. Mine was the Aeroplus Lite,

68

Mine too.

69

Hi Peter.
Have you made any further progress?

70

Hello David,
No not made any further progress as tbh I’ve run out of ideas at the moment (and also time). The weather has also been foul up here during most of the free time I’ve had so not had much chance to ride. As it is at the moment it’s way better than it’s ever been, so a decent work-around I think, but the basic problem remains. Perhaps a completely new programme would be the answer but I wouldn’t feel confident enough to do that.

For the moment I’m putting up with the red light, just a little niggle really in the great scheme of things…

Thanks for the interest

Peter