106 1.5d misfire

[scfc_151]

When the car is cold in pretty much kangaroos its way down the road and when it does stutter it pours blue smoke.

It disapears when it warms up

The battery test has been fine and glow plugs replaced.

I was wondering if there was a cold start mechanism on the fuel pump?

Any advise appreciated

thanks

[CitroJim]

Yes, there is a cold start mechanism, both to advance the timing when cold and to increase the idle.

If the car has a Lucas pump then the cold start advance solenoid is actuated by a contact set on the end of the fast idle lever. Look for a black wire and a small rubber bellows - this contains the contact. I expect the fast idle lever will be operated by a bowden cable disappearing off to a 'waxstat' in the thermostat housing. If so then this component often fails resulting in no fast idle and no cold advance.

I'm guessing here as I've had no direct experience of the 1.5D but this is how it's done in many other PSA diesels with Lucas pumps from this period.

If the car has a Bosch pump then a similar setup will exist but will operate differently.

Having said that, the cold advance does not make that much difference in reality...

Does the engine start easily when cold or is it difficult? If difficult check the valve clearances as they might have closed up.

[DickieG]

Has the glowplug circuit been tested? Not sure if this applies to the 1.5D but a number of diesels from that era have post start heating where the glowplugs continue to glow for several minutes after the engine has started.

[Lighty]

The 106 can suffer from the "no valve clearance "problem , did a set on a Saxo last week, transformed the car, but mainly wouldnt start when cold.

[citronut]

i have got a brand new still on the pallet it came from the factory 1.5 TUD lump if you need it

regards malcolm

[spider]

They do have the post heating on some but that along with the actual cold start advance (not fitted to some later models! possibly 'hot countries' designation) do not really seem to make that much difference. It only increases the idle speed, I don't think it has a timing advance on a TUD I'd have to check as usually its the TD models that have it, and there's no TUDT.

Without the waxstat (on an XUD I'll admit) it just tries to idle at 500ish rpm when stone cold. The post heating does not seem to make a huge difference in reality.

[scfc_151]

Hi,

Thanks for the replies all.

Ive test that all plugs are getting 12v and the car has no problem starting. The battery is old though so ill be replacing this soon in light of all the cold weather.

The car has over 145,000 on the clock now. Just out of intrest how much would you want for the engine you have malcolm?

Thanks again

[citronut]

pm sent

[scfc_151]

Hi thanks for all the replies. 1 important point that I forgot to mention is that the fuel ecomony is very poor on this car. It gets around 300 miles out of a 45 litre tank. I was wondering if this ties in with valve clearences or could this be something else?

Cheers

[CitroJim]

I was wondering if this ties in with valve clearences or could this be something else?

Valve clearances are well worth checking and it could be the cause but poor fuel economy and poor cold running points much more to a timing fault in my view. I'd say the engine was running a tad on the retarded side or the automatic advance mechanism in the pump has stopped working. Diesels, jut like petrols need to advance their timing with increasing engine speed.

Diesel timing, especially on these little tiddlers of engines is very critical.

[spider]

I was thinking a timing concern too.

Does it smoke / actually sound 'OK' when its running ?

If I remember correctly, the timing on these is adjusted via the actual sprocket, the pump fixing holes are not elongated so the pump can only fit in one exact spot really rather than being a "twist" ( ) unit as the XUD's. The cam / pump sprockets have three bolts and elongated holes to facilitate its adjustment at belt fitting time.

EDIT... I do wonder if its possible these have moved slightly, after all they are only tiny bolts, seems unlikely now I've said it but you never know, then again the belt would be slack if they did move.

My other thought was a fault with the pump itself, a stuck advance / retard mechanism internally but that seems quite unlikely too, I cannot recall seeing a TUD with a 'bad' pump...

[scfc_151]

It does kick out lots of blue smoke when it misfires and sounds like it runs fine when its warmed up

[wheeler]

Re: valve clearances, well worth a check, very common problem, if the shims need done there is a special tool available that lets you do them without having to remove the camshaft.
See here > http://www.shopwiki.co.uk/d/661246/5668 ... sel-Engine" onclick="window.open(this.href);return false;

[Peter.N.]

Hi,

Thanks for the replies all.

Ive test that all plugs are getting 12v and the car has no problem starting. The battery is old though so ill be replacing this soon in light of all the cold weather.

The car has over 145,000 on the clock now. Just out of intrest how much would you want for the engine you have malcolm?

Thanks again

If you are getting 12 volts on you plugs they are not alright, as they draw something like 60 amps you will get a voltage drop, if they are all working you should have only 10-11 volts.

Peter

[scfc_151]

Thanks Peter

Ill re-check this with another multimeter. Ive individually checked the plugs and they seem to heat up quickly and fully. I was wondering whether the plugs are staying hot for long enough.

I did notice that the plug on the 2nd cylinder had lots of oil coated on it. Is this normal?