306 turbo diesel starting problem

I have a 1995 306 turbo diesel. Whenever I start it (when it is hot or cold)
it always idles rough for between 5 to 30 seconds (unless I rev it) then
smooths out at which point a load of smoke is emitted. I have checked the
glow plugs and all seem to be fine. Is there anything else that could cause
this? Any help would be appreciated.

 

Air in the fuel?

 

I don't want to seem to pour scorn on your diagnostic prowes,
but checking glowplugs isn't the simplest of matters.
The only sure way is to replace them (imho).
They can go open circuit, dead short or more usualy partialy short circuit
and the fact that when healthy they only measure about 0.4 OHM when cold
doesn't make for an easy check.
The nearest I've experienced to a decent check is putting them across a
battery
to see if they glow, although even this won't check what they do under
pressure.
Course it could also be air getting in ;-)

Good name(!)

jim.

 

Have exactly the same car, and the same problem. One cylinder seems to
need some more time to start, and then the diesel in that cylinder
comes out in a white cloud of smoke. On a visual check all my glow
plugs seem to work fine. I know that one cylinder is lagging in
compression (2.9 vs 3.2 bar). I suspect that there is a small leak in
the head gasket. It is a bit strange but my car starts flawlessly only
when it has not been used for 2 weeks. When I use it on a regular
basis it helps when I start 10 seconds after the glow plug indicator
light has switched off. This might indicate that the problem is a
combination of a failing glow plug and the reduced compression.
The car that has done 285.000 km without problems. My other car is a
new Golf V, but I prefer to drive the Peugeot. So I might even spend
the money to replace the headgasket and glowplugs.

Hope this helps.
Hans
the Netherlads

 

Another thing to check is that they have been torqued up
correctly, particularly on the No1 cylinder which is difficult
to get to without dismantling everything. I found mine was
"loose" and that the threads were blackened and oily, compared
to the others which were clean. This might affect compression
as mentioned elsewhere is this thread.

Everyone has mentioned air, but in case you dont know how
to check, replace the pipe going from the fuel filter to
the pump with a clear one, if it hasn't already been done.
It should be quite obvious if you have an air leak.

If you get quite a lot of air pooling in the tube after leaving
the car standing for a while, first check that the cap on the
fuel filter, otherwise it could be the seals in the pump.

-Mark

 

Thanks Mark. I was going to post to ask how to check if there was air
getting in. I will do this and see what happens.

James.