Hi,

My sisley has just started to exhibit a worrying problem.
In 3rd,4th and 5th gear it will occasionally sound like its going to stall i.e chug a bit then recover and acelerate again. Only happens when accelerating and not in 1st or 2nd gear (probably cause I don't acelerate in them much). I've been putting it in neutral and then reseelcting the same gear and it seems to recover but probably cause I've gone slower to change into the gear in the first place.
Gearbox is not making any odd nosies and gear selection is fine.

Any ideas?

zulu705 said:

Hi,

My sisley has just started to exhibit a worrying problem.
In 3rd,4th and 5th gear it will occasionally sound like its going to stall i.e chug a bit then recover and acelerate again. Only happens when accelerating and not in 1st or 2nd gear (probably cause I don't acelerate in them much). I've been putting it in neutral and then reseelcting the same gear and it seems to recover but probably cause I've gone slower to change into the gear in the first place.
Gearbox is not making any odd nosies and gear selection is fine.

Any ideas?

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Accelerator pump diaphragm split? Vacuum air leak somewhere? Possible distributor vacuum unit failed?

Thanks for the reply.

Had a new vacuum advance last month.

Worried the gearbox has died but going to throw fuel filter and maybe sparks at it in the hope that these will miracurously fix it.

What makes you think the gearbox is the problem? I can't think of a link between the two unless the gearbox sounds like it's dragging off the floor.

I had a gearbox go on the way to Scotland in my first Sisley and the sound was incredible but I still got there

Alan.D said:

What makes you think the gearbox is the problem? I can't think of a link between the two unless the gearbox sounds like it's dragging off the floor.

I had a gearbox go on the way to Scotland in my first Sisley and the sound was incredible but I still got there

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Probably because I changed the oil in it a couple of weeks ago and just assumed I'd done something wrong! plus it went out of of gear a couple of times after it did the chugging.
Tonite it was doing it again, boyfriend drove it to see what was wrong and apparently it was ok, maybe a slight misfire. Then when I drove it again it was fine!
I am going to change the fuel filter at the weekend since I've already got one so we'll see what happens then.

I would confidenty ay it's not the box, before they give up they are very noisy.

Ok its not the gearbox. Thank goodness.

It stalled and died completely tonite, had to get jump started then the drive back was exciting. The chugging was horrendous! apparently there was lots of black smoke coming out of the exhaust.

So it is misfiring badly then, what would cause that?

We put a new distributor cap on as I knew the old one was on its way out (see pic) but the new cap didn't really make any difference

What else should I try?

Thanks for the advice so far.

Timing, plugs, leads, fuel filter if it has one, carb, you changed the cap but did you change the rotor arm as that cap looks very poor condition, have it put on a Co meter to check that it's not running too rich or lean.

Also check the oil for creamy deposits and see if you are getting any oil in your coolant.


Just thought, there is a little electronic box on the back of the dizzy. Have a look at the wiring to see if it's frayed.

Thanks Alan ! I'm going to have a busy weekend

Didn't change the rotor arm as don't have one. Where is best to get one?
The oil seems fine.
Passed its mot in Jan and passed the emissons test so I assume the mixture is fine?

I have plug, leads and a fuel filter so will change them.

Looking at the state of the dizzy the rotor arm may not be in very good nick but it's just another link in the chain of symtoms that could be the problem? Most motor factors will stock them and they are a couple of quid.

Quick update. Changed the spark plugs today, there was an actual insect on one of them anyway with plugs changed and jump started it runs fine at idle and warms up so choke can be pushed back but under acceleration it still misfires

Re: replacing the rotor arm, the only motor factors I know is Halfords and eBay and no luck there at the moment.

Next is to change fuel filter, does that seem a likely culprit? or maybe the carb? Does the fact that it runs great at idle mean anything or rule anything out?

Unless the fuel filter is near blocked solid it should still allow enough fuel through. I'd still bet on the rotor arm......I'll see if i can dig out a spare make sure it's clean and send it up/down. If I find one I'll ask to PM your addy if not I'll get one from my local factors and send it on.

Just thinking the original sisley carb has a little fuel filter bolted in next to the inlet pipe it's just a little nylon mesh thing other than that it wasn't fitted as standard unless someone has added one in the past.

Possibly the carb but you would need to put it on a C0 test.

Thanks for that great offer Alan. :worship:

I have now located a local motor factor and they should get me one in for tomorrow for £3.70.

I was reading in the Haynes manual about the mesh filter on the carb so I'll have a look at that too.

Once again thanks for the offer.

Got rotor arm, fitted rotor arm. Still same problem :bang:

Fuel filter was also changed.

So now, carb? Bought carb cleaner but not entirely sure where to spray it (other than in the carb ).

Emailed a couple of places I found via google and a repair kit for the carb is £42 is that right?

I miss driving it

A couple of things to check if the misfire is only at higher revs.

• Check/ replace air filter - If it blocked it will cause the engine to run rich, which might explain the black smoke you experienced (classic sign of an over-rich mixture).
  
• Check/ replace coil - High rev misfires are often a sign of a coil failing. They start to break down and cannot supply a strong enough spark at high revs but still work ok at lower revs. You can also check the low tension side by making sure the connections are clean and secure.

Otherwise I'd suggest getting it hooked up to an exhaust gas analyser to try and pin point where exactly the problem is.

Thanks for the replys.

I am going to get a carb repair kit and see if that helps. Sprayed carb cleaner all over and in the carb today and it seemed to help slightly so maybe I'm on the right track now.

I have a question though. How full should the fuel filter get when reving the engine? The level never seems to be over half and also seems to be just beneath the level of the offtake pipe, is that right? I have one of the halfords clear filters so I can see the level.

Sorry mate I feel for you :bang: I will ave a good think and return.

zulu705 said:

I have a question though. How full should the fuel filter get when reving the engine? The level never seems to be over half and also seems to be just beneath the level of the offtake pipe, is that right? I have one of the halfords clear filters so I can see the level.

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That's perfectly normal. Both my 999cc FIRE engines were like that and ran fine. I too worried that something was amiss when I first saw it, but 70K miles later I realised that it makes no difference to the running!

Thanks for the support

Thats fine about the filter I'll hold off ordering a fuel pump from the motor factors tomorrow then.

Took the distributor apart and these wires are very frayed were these the wires you first mentioned Alan? Is this the inductive pickup? How on earth is it still even running ?!

Yep that's what I was reffering to, you may have the problem there. I may have a spare of that will look tomorrow.