Idle Speed 1.9TD

[davehughes]

I have tried to find this out from the BoL and give up

What should the idle speed be on my 1.9 SX TD 1993 Xantia be;

1 When cold

2 When warmed up?

It always seems to be just under a thousand regardless of whether I am starting it on a cold morning or if it has been running for an hour and a half (I have a 120 mile round trip to work every day)

Dave

[KevMayer]

Haynes says:-

Non Aircon car warm 800 +- (plus or minus) 50

cold 950 +- 50

If you have aircon the warm setting should be 850 +- 50.

You probably have a wax stat that pulls on the cable to your pump. If you are stuck at the cold (fast idle) setting then maybe your wax stat has packed up.

I was told recently that a new wax stat is approx 18 quid from Citroen.

It fits on the side of the housing on which the fuel filter sits.

Hope this helps.

[AndersDK]

I'd set the rpm's a bit higher to avoid the whole car shaking by the engine.

A '93 would have the waxstat coldstart idle control. Its easy to replace :
With cold engine (!) bleed some 0.5L of coolant off the system. Then the waxstat fitting should not spill that much coolant.
Replace waxstat using a new seal.
Fit cable and tighten it up as much you can using handforce ensuring the control arm is pulled fully home against the spring.
Recheck when job finished that control arm is held tight against the stop by the cable.

Now top up coolant and let engine reach normal temp. Note the higher idle rpm's and a slightly different engine note. A bit more harsh diesel clatter. When engine warms up the engine rpm settles down and engine will be more quiet. Note the idle control arm is now released by the slack waxstat cable.

Once the cooling fan starts cutting in/out - adjust the throttle stop for your personal like of normal idle revs. Dont get it too low.
There will be a 3.rd setting somewhere on top of the rotopump. This adjust the (anti-) stall tendency. Do not touch unless the engine tends to stall on throttle release.

Finally re-check coolant level when engine has cooled.

Note : the waxstat is a standard device for all PSA diesel models, and may come with too long a cable fitted. Simply cut to fit.

[bxbodger]

The waxstat is easy to check-the cable operates an arm which has two positions, one for hot , one for cold, with a screw adjuster for each.Don't go buying a new one unless you have too!!!

When cold,the cable is tight and pulls the arm over against one screw adjuster, when the engine is hot the cable will feel slack and the arm will be against the other screw adjuster.

Make sure the cable is adjusted tight when its cold, and If its working properly, it will do the above, if not, then it won't- simple as that!!!

Set the revs by ear-like Anders says, so the engine doesn't shake when cold. Ignore the rev counter figure- they are a pointless acssessory on a diesel anyway-you can't over-rev it, the governor won't let you!!!

Its not like a petrol choke so even if its not working properly, it won't really matter.

Funnily enough, the one on my BX never seemed to make any difference to the revs, either, until I fitted overhauled injectors- then the effect was noticeable

[jeremy]

I agree with all that has been said before - except - that the waxstat device should give an increase in idling speed - so if yours is idling at 1000 when hot (which will sound slightly fast) someone has adjusted the idling to compensate for a failed waxstat.

When I left the thing disconnected on my BX TD its cold idle dropped and the thing was hunting when cold - fine when hot! (Rotodiesel pump with electric timing advance). I think this was due to the governor part of the pump preventing it stalling but not being able to sustain consistent idling - so revs drop, governor prevents stalling and speeds it up - revs drop and cycle begins again!)

The chances are it will smoke when cold as well. The change on Roto-diesel from an idle adjustment to the timing method was to reduce smoke apparently.

jeremy