5 replies to this topic

[spiguy]

Hi folks,

 

I have a 1992 Spi cooper. I've posted on here before that I feel that the car runs a little lean. Not so much that I think there is anything particularly wrong, I just think it's a bit lean. The plugs are very light indeed (almost white) and it lacks a little pull (I think).

 

I keep seeing posts from people with running issues which ends up being the all too common Spi vaccuum pipe to the MAP sensor on the ECU. When the ECU doesn't see the vacuum, it ends up overfuelling horribly. This made me wonder. Would it be possible to slightly enrich the SPi by delibirately introducing a small air bleed on this pipe?  You can get valves which allow you to do this for compressed air lines etc. I would just T the vac line into the bleed valve.

 

I just wondered what people thought this would do. I'll probably try it in any case as I can't see that it would do any harm to try it out briefly, and assess plug colour, mpg etc. But does anyone think it could work (or not) ? 

 

Cheers

Craig

[Steve220]

To do this properly you would need an exhaust gas analysis tool. This would show up whether you are fuelling correctly in the first place. Rather than just putting a plaster over the problem, don't you think it would be wise to cure what is causing it to run lean in the first place?

[Fast Ivan]

I guess you could fudge a way of doing it and you could use the lambda readings to see where its at maybe but it would be a bit hit and miss to be honest.

 

there's clearly another issue somewhere though...

[FlyingScot]

Craig better to sort out why she's fuelling lean There's a guy in your club has 17 diagnostic code readers

If I had to work out a simple way to do it I wouldn't use the MAP as it has too large an effect, the ECT sensor would be the way I would choose.

FS

[spiguy]

ha ha.. yeah minicomic, I heard about that guy... Think I should take him up on his kind offer to hook me up   I should probably make a bid on one from you, I like to tinker with these things! If only the salt would all go away from the roads I might actually take the mini out!

[Badboytunes]

Have it rolling roaded to confirm any fuelling issued before fiddling, IMO