306 D Turbo Starts on 3 Cyliners

Okay this one is confusing me now. Seen a few posts saying the same
thing.

Car starts and runs very lumpy with what seems like only 3 cylinders
firing. This is accompanied by black and white smoke which gives and
sort of grey as the mix. A few seconds and it clears and all is fine,
alternatively blip the throttle and it clears. It always clears with a
puff of black smoke. The cold makes the situation worse.

I have replaced all the glowplugs but still suffer from the problem.
Car is a 95 with 84K miles on the clock.

I suspected worn injectors but have been adviced to get a compression
test. Spoke to local garage and they say there is no point as if it
were low compression it would run on 3 cyliners constanly (not so sure
about that).

Here is the starnge thing, I have found (purely by accident) that if I
give the priming pump a couple of pumps before I cold start it, the
problem does not seem to occur. I get a tiny bit of smoke, but it does
not run on 3 cylinders. What does this suggest? Injector pump?

Don't know where else to go with this one, so any help would be much
appreciated. Using the process of elimination on this sort of thing can
be expensive, time consuming and inconclusive, so any suggestions are
very welcome.

Thanks all in advance,
Adam

 

Symptoms are as for duff glowplug(s).
Priming the pump to cure it suggests fuel leakage.
Odd.
DaveK.

 

Dave
It is quite likely the seals in the bulb priming pump are allowing fuel to
drain back into the tank. This is a common problem with 406's
Mike

 

Have you checked that the glow plugs actually glow i.e. that the cable
connection to every glow plug is working?

 

Thanks for this Dave, pretty interesting. I am going to have a
general hunt round the whole fuel system for a possible leak, but was
wondering how I can check the seals in the priming bulb? Should I
remove the tank side pipe and see if I get diesel flowing back out of
it?