930 fuel problem, occasionally running very rich

[08jay]

Hi, my 86 930 has an intermittent fuel problem. It always starts fine hot or cold but approx once a week it will start normally but run very rich, making black smoke under load and have hardly any power. Restarting it doesn't help but it is normally fine the next day. Both fuel pumps are only 2 years old. Does anyone know if this could be a relay problem or a Warm up fuel regulator or anything else?

The heater has also got a mind of it's own often coming on even when it is switched off. Has anyone else had this problem before?

Any tips on locating the source of the problems would be greatly appreciated,
Thanks

[hatchn]

Sounds to me like a faulty warm up regulator. Mine did exactly the same thing a few years back.

[therevday]

Next time it starts running rich give the wur a little tap with a small hammer.Mine used to do the same in the end I replaced it with a Brian Leask adjustable wur.Stuart Paterson (stup on here) is an expert when it comes to 930 fueling.

[08jay]

Ok thanks very much for your help, hopefully it happens again soon and I can try it. Be handy if I could isolate the problem that quickly.

[08jay]

Unfortunately the tapping the warm up regulator didn’t work on this occasion, so I will have to keep searching for the problem. If you have any other suggestions which might help locate the problem please let me know.

[MrCooke]

It might be the warm up regulator but could equally be the fuel distribution unit or air flow sensor. If you're not experienced with it K-Jet is a proper pain to trouble shoot without just throwing money at new bits one-by-one until you strike lucky.

It's not going to be cheap but you really need to either pay someone who knows the system to look at it for you or unbolt all of the bits yourself and send them to someone like Ken Mills Injection for testing and rebuilding.