Timing and fueling sorted, plus struts sorted

maxgreenwood · Post by **maxgreenwood** » Wed Jul 13, 2011 11:43 pm

This evening i replaced the vacuum advance capsule on my distributor - (Bosch). I got a new one through a local Cit garage, which they ordered based on the chassis number, €30. Fitted, dist and cap all cleaned up, the low end torque has now returned and engine feels great again.

However, I have a new noise under acceleration, which i'm guessing must be 'pinking' being new petrol engines. It's not really bad but it certainly wasn't there before.

Thinking about how it all fits together afterwards, i made the textbook mistake of not checking the new part against the old carefully enough.., maybe... the capsule was exactly the same but i wonder if the arm that extends into the distributor may be slightly different in length and be affecting the timing, and so making it pink. I marked the timing position of the distributor before removal and realigned the same when back on.

So i could experiment with the position of the distributor and see if it goes away which i might try tomorrow.

Post by **mat_fenwick** » Thu Jul 14, 2011 12:04 am

Perhaps it's been set (advanced) to partially compensate for the lack of vacuum advance - and now that's sorted you're running too much advance under load? Or simply that the book settings are not optimum for your engine/fuel.
Experimentation is a good idea IMO - you could set it to be 'correct' if you have a timing light but that may not necessarily be optimum, as things like fuel composition will have changed since the design of the engine.

I would retard it a shade until it *just* stops pinking, then you should be pretty close to optimum.

There is a chance the mechanical advance weight springs are a little tired (these advance the timing based on engine speed). This would have the effect of greater advance earlier in the rev range. But don't worry about that just yet!

maxgreenwood · Post by **maxgreenwood** » Thu Jul 14, 2011 12:20 am

Well if all it involves is getting a shade retarded, I'm quite good at that..

I was hoping to relax my timing with you guys this weekend. I'm still looking into crazy fly in-out options but i don't think it's possible unless something gets cancelled this end.

Thanks Mat, I'll get the toolkit out again tomorrow.

maxgreenwood · Post by **maxgreenwood** » Fri Jul 15, 2011 11:06 am

i've experimented with the timing by rotating the distributor a little. I can't get rid of the noise, although it changes from being on acceleration to happening when lifting off the throttle slowing down, depending on where i set it.

I'm not sure it is 'pinking' either - it is a knocking sound that sounds like it's from the bottom of the engine - not severe, but part of the combustion and most noticeable between 1000 - 1700 rpm at normal throttle. I can get the garage to look at it, early to mid next week, but i just don't want to be damaging the engine in the meantime.

maxgreenwood · Post by **maxgreenwood** » Sat Jul 16, 2011 4:32 am

ok i think i've been on the wrong track here. I don't think it's pinking i'm getting. These are the facts:

The 'knocking' through 1-2000rpm appeared after i took off the distributor to change the vacuum capsule and re-attached.

altering the timing by moving the distributor makes no difference to the noise.

It sounds like this, maybe not quite as bad and more dicernable from inside the cabin:

from the comments it seems like that is crankshaft..
could this fault have revealed itself on mine now i have increased torque at low revs from the new vacuum advance caps?
The car has run low on oil a while back, no lights came on though and they work.

and generally my engine sounds a bit noisy like this:

I'll see if i can make a video with sound.

Hope you're all having a good time at the National! Wish i was there.

maxgreenwood · Post by **maxgreenwood** » Thu Jul 28, 2011 8:44 pm

I took the car to the garage to get them to set up the timing, fueling and have a good look over things.

All is well. The noise i was getting is 'rumble' from the crankshaft. They've heard it on a number of them over the years and apparently is nothing fatal, i thought it was the engine knocking, it sounds quite similar.

I thought i needed two new front spheres as the ride seemed firm after fitting my re-con struts. However, over the last couple of weeks the ride has gotten better and better up front and is now lovely and supple and floaty. There seems to have been a wearing in period with the struts. The garage confirms the spheres are fine. Although the LHM in there is pretty good, i'm going to change it and do the filters to make sure those struts don't wear in anymore!

So I'm quite relieved everything is ok. The car is driving great now it's been set up properly too. Bxing is putting a smile back on my face.

mnde · Post by **mnde** » Thu Jul 28, 2011 10:38 pm

Hey Max, that's my car in video no. 2!

I'm aircoolcrazy on Youtube.

Wonder if my car would benefit from new vacuum capsule too - it's always had terrible low down torque and I have to set the timing a tad retarded from 10 degrees to avoid pinking.

Mark.

maxgreenwood · Post by **maxgreenwood** » Thu Jul 28, 2011 10:50 pm

Hi Mark,
you can check the vacuum advance capsule operation by taking the pipe off at the carburettor end that runs from it to the carb, suck on it, you should feel resistance and the sound of the diaphragm clicking back when you release, if you can suck any air through then the diaphragm has gone and you'll need a new one. Mine was €30 prob £20 in uk, give Citroen dealer your chassis number and they'll find the right part. Quite easy to fit, just be careful taking the distributor apart with all the screws etc, a little fiddly to locate the arm protruding from the capsule, but quite straightforward really. I'm no mechanic but did it fine. Interesting how these things work as well.

I fiddled for a while with fueling, timing and idle and got it no where near. It drives really smooth now since the garage set it up.

Hows the GSA estate running? I'd love one of those

Post by **Tim Leech** » Thu Jul 28, 2011 11:11 pm

Hi Max

My low miles 16TRS (43k with FSH) has the same rumble as yours and ive heard it before on a few 1.6's. Also the 1.4tu ZX does a similar thing but runs fine.

Guess its just one of those things! I wouldnt worry!

maxgreenwood · Post by **maxgreenwood** » Thu Jul 28, 2011 11:23 pm

Hi Tim,
that's good to hear. I think i've found my caring Citroen guru in the shape of this experienced BX guy i just had it with. In contrast to the garage before, who we discovered fitted the lower engine mount the wrong way round after doing the Octopus job.

I used them as they were convenient distance wise, but i've had loads of hassle with them. We've moved closer to the other one now so i'm happy to be using them again. Unless you can do all the work yourself, it's so important to have a BX experienced garage that actually give a sh*t or understands where you're coming from in loving these cars.

For anyone in Dublin that's interested: Kevin Barry Motors in Walkinstown come highly recommended.

toddao · Post by **toddao** » Fri Jul 29, 2011 9:14 am

Max confessed

this experienced BX guy i just had it with

that's one way to pay the garage bills!

maxgreenwood · Post by **maxgreenwood** » Fri Jul 29, 2011 9:22 am

where needs must