Citroen XM Forum

citroenxm wrote: Sun Oct 30, 2022 12:24 pm I didn't think the xm had a throttle lever damper on xm. Only on 1.9 engines in 306s and xantias.

I couldn't remeber, they do still have the ball joints for the damper, but since most have been removed anyway it's hard to remember.

citroenxm wrote: Sun Oct 30, 2022 12:24 pm
Tell me also will, the rear is a timing advance for cold start, so whats the front mechanism that's controlled by the coolant jacket to the side of the pump .. its like a second advance unit.

You are correct, the rear is idle speed only the front is timing advance, both for cold start operation.
I was answering from memory and without actually checking a pump.

As long as it starts straight away from cold it doesn't matter. We just don't see temperatures cold enough for it to be an issue and the Uk switches to winter diesel 15th November until 15th March to avoid waxing issues. Deliveries from depots are switched from 1st November.
Winter diesel is a lighter fraction than summer diesel so easier starting and lower viscosity, but lower calorific value, thus one reason for Mpg drop in winter, even for the same ambient temperature and operating conditions.

maxferreira wrote: Sun Oct 30, 2022 12:30 pm it's the minimum position screw, the horizontal one at the rear

i've been using that to tweak the idle to where it is now

idles back down fine after being revved, bear in mind however the idle switch is presently disconnected

cold starting and idling is fine, i admit it does idle a bit high but it's smooth

The horizontal screw is the anti-stall screw, not the idle speed screw.
Look over to the rear of the pump in line with the accelerator shaft and you will see the cold and warm idle lever, which is adjusted by two vertical screws.

Dieselman wrote: Sun Oct 30, 2022 3:55 pm

citroenxm wrote: Sun Oct 30, 2022 12:24 pm I didn't think the xm had a throttle lever damper on xm. Only on 1.9 engines in 306s and xantias.

I couldn't remeber, they do still have the ball joints for the damper, but since most have been removed anyway it's hard to remember.

citroenxm wrote: Sun Oct 30, 2022 12:24 pm
Tell me also will, the rear is a timing advance for cold start, so whats the front mechanism that's controlled by the coolant jacket to the side of the pump .. its like a second advance unit.

You are correct, the rear is idle speed only the front is timing advance, both for cold start operation.
I was answering from memory and without actually checking a pump.

As long as it starts straight away from cold it doesn't matter. We just don't see temperatures cold enough for it to be an issue and the Uk switches to winter diesel 15th November until 15th March to avoid waxing issues. Deliveries from depots are switched from 1st November.
Winter diesel is a lighter fraction than summer diesel so easier starting and lower viscosity, but lower calorific value, thus one reason for Mpg drop in winter, even for the same ambient temperature and operating conditions.

No need for the embarrassing emoji. Memory recalls are what I often use also.. I understand now. I always thought the rear one advanced the timing but, clearly it only ups the fuel for a faster.idle. the front I was aware is timing related, K ban original pump had.timing issues and wouldn't run well unless the advance was pulled right up to the right on the cable..

I've therefore since learnt that this is what led me out of my bx tzd turbo 25 odd years ago when the timing on the pump started playing up at 175k. It had a bosch pump identical to the xm one with the advancer on the front, I had no idea that pulling it up would of cured the cold start smoke it had untill it got warm prior to a pump dismantle. But.. there we are those were the days.

thank you

yes i shall check all of the screws tomorrow

took it to work at my new job today, parked on the high street and proved very popular indeed! lots of compliments and people talking about it which was nice

stalled after startup so idle and anti stall still aren't correct but it's running well really

my apologies, i'm rather tired so i will read through your replies properly tomorrow and give a proper reply

i need to pop a nut on the anti stall screw as it keeps coming un done

otherwise, i can't report any issues.....staggeringly!

been doing a lot of miles in it this week, it's driving absolutely great!

Is there not a spare adjustment screw you can take the nut from?

We were confident your work would all be Ok.

I’m sure there will be

I’ll take a look tomorrow and see what I can do

stole a nut from one of the screws on the front

the short one at the top, no idea what it's for

anyway, it idles around 1,000 rpm again, not bothered with that especially as winter is approaching as it'll allow for slightly better battery charging and faster warm up etc

went out this evening to help a friend with his CX safari, decided to pop the XM into sport suspension and really push on it through some roundabouts, handles well!

drove the car quite hard too, loads and loads of clag came out the back the first time i went near full throttle before clearing up, running way better now too!

done a comparison between hydractive 2 and hydractive 3+ today, i still say the C5 with h3+ has the edge on handling, bit flatter and more planted

rather pleased with my cars at the minute, and glad the XM is now at the point where i'd say it's a good car

i think my next task is to maybe sort the interior lights

i have one, which is the o/s rear, the others are dead due to a fire

all puddle lights in the doors work, also no boot light but that's fine

so it needs rewiring, i could get a loom, or i could simply just rewire it and see where that gets me, doesn't seem too difficult and i've got ample spare cable

maybe a task for tomorrow? shall see how i feel

maxferreira wrote: Thu Nov 03, 2022 9:54 pm stole a nut from one of the screws on the front

the short one at the top, no idea what it's for

Not used on this application.

maxferreira wrote: Thu Nov 03, 2022 9:54 pm
anyway, it idles around 1,000 rpm again, not bothered with that especially as winter is approaching as it'll allow for slightly better battery charging and faster warm up etc

drove the car quite hard too, loads and loads of clag came out the back the first time i went near full throttle before clearing up, running way better now too!

Sounds like the fuelling screw is turned out a bit too far, so overfuelling off boost and idling too high.