The ongoing journey of Spartacus’ 1988 Fiat Panda

[wesacosa]

what a fiddly ball ache getting the inner gaiter back on 

there is no clip on the gearbox end just the metal plate and 3 screws but the trouble is when its in situ you can't see all the way around the circumference to see if the rubber gaiter has seated on the metal flange because the metal plate and numerous bits of car are in your way. It's probably easier on a ramp but because its the long shaft side you need to do it on your back from underneath when you only have jack and stands.  You need 3 pairs of eyes and two pairs of very small hands 

I've now ran out of light and patience for the day.  

[wesacosa]

On 07/06/2024 at 18:56, Ian_Fearn said:

@wesacosa the answer is yes idle speed will be affected by the work you have done (it sounds like you’ve made some fairly large changes). You will need to adjust the idle speed back down.

I would reset the idle mixture on the carb first though. It’s been a few years now for me but I had a lot of success with a Gunsons colourtune for tweaking the idle mixture.

Have you managed to use a colourtune on a FIRE engine?  Even with the longer adapter I can't get the colourtune plug in as the 21mm socket it needs is too fat for the plug recess on all 4 plugs

[Ian_Fearn]

On 13/07/2024 at 15:52, wesacosa said:

Have you managed to use a colourtune on a FIRE engine?  Even with the longer adapter I can't get the colourtune plug in as the 21mm socket it needs is too fat for the plug recess on all 4 plugs

Wes, what does your colourtune kit look like? I think there’s been a few iterations over the years and it’s been a good while since I last used mine. I’ll happily send mine to you it it’s different to yours.

[wesacosa]

4 minutes ago, Ian_Fearn said:

Wes, what does your colourtune kit look like? I think there’s been a few iterations over the years and it’s been a good while since I last used mine. I’ll happily send mine to you it it’s different to yours.

thanks that's a kind offer. I borrowed a bit of a retro one from @rob88h I don't have a picture of the kit but its mid 80s I think from some of the paperwork in the box. This is the colortune itself though, its a 14mm but takes a 21mm socket. I was going to try and dig out my thin wall alloy wheel sockets tonight to see if there is a 21mm in there and see if that fits 

I bought a Gunson 14mm extender in the hope it would raise the 21mm nut clear of the bits of block that were stopping it but it wasn't enough to do so

 

[Ian_Fearn]

This is mine. It has a 16mm nut size. Mine is circa 1997/8.

[Ian_Fearn]

I also have this older version which is the same as yours with a 21mm head.

[wesacosa]

ah ok that makes some sense then , they must have made a slimmed down version as more engines had recessed plugs.  The kit I borrowed does look like the bottom one in that dark coloured cardboard box 

[Ian_Fearn]

If you are still struggling with a slimmer 21mm socket then let me know and I’ll send the newer kit to you.

[wesacosa]

9 minutes ago, Ian_Fearn said:

If you are still struggling with a slimmer 21mm socket then let me know and I’ll send the newer kit to you.

thanks mate. that's very kind. I will check this evening 

[wesacosa]

20 hours ago, Ian_Fearn said:

If you are still struggling with a slimmer 21mm socket then let me know and I’ll send the newer kit to you.

I tried the thin walled socket last night but it was still too big.  However I think my supervisor at work may have a later one (his Dad was actually the joint inventor of Colortune!) so he is going to check this evening for me. If that doesn't work out I will let you know

[wesacosa]

Haven't had a play around with the mixture yet. I did drop the idle speed though.  However its not running great as you can pick up here.  If I press the throttle from idle slowly or only by few mm it picks up cleanly, if I press it quickly and beyond a few mm it doesn't rev cleanly or even cuts out. wondered if it was the accelerator pump but that appears to be working correctly.  Wonder what else it could be.  I seem to think @spartacus cleaned the carb but not sure if he changed any gaskets or seals.  Unless its the mixture or carb gaskets I'm struggling as I'm pretty sure I've replaced everything else !

 

[Mr Pastry]

That seems to be with a cold engine, if the temp gauge is correct.  What is it like when properly warmed up?

[wesacosa]

3 minutes ago, Mr Pastry said:

That seems to be with a cold engine, if the temp gauge is correct.  What is it like when properly warmed up?

better but not perfect.   

This was me testing the hot idle with the colourtune (which I've now had to return before I could really play with the settings) You can hear it stumbling and the colourtune flashes both yellow and blue

https://youtu.be/DSfCVvc7fuM?si=aqJsazdNN5JZ9d7V

[rob88h]

I was going to say accelerator pump on the carb with those symptoms. Can you see it squirting fuel or just the linkage operating? Perhaps a duff diaphragm or blocked outlet, so it looks like it operated but isn’t popping fuel in to the throttle.  

Alternatively, do these use vacuum advance for the timing? Maybe a vacuum leak on the advance?

[wesacosa]

1 minute ago, rob88h said:

I was going to say accelerator pump on the carb with those symptoms. Can you see it squirting fuel or just the linkage operating? Perhaps a duff diaphragm or blocked outlet, so it looks like it operated but isn’t popping fuel in to the throttle.  

Alternatively, do these use vacuum advance for the timing? Maybe a vacuum leak on the advance?

I did check the accelerator pump and it was squirting but it wasn't stumbling then, maybe its intermittent. I will try and get someone to blip throttle for me whilst I look 

there is a vacuum advance on the dizzy but its new as is the pipe so pretty sure its not leaking (when the pipe had a split in it previously it just wouldn't idle full stop)

[wesacosa]

Not sure if I've had a potential breakthrough on the poor running 

I noticed after a very short spin on private land* that when I took the air box off there was a bit of a petrol smell and fluid accumulation in the areas with the red arrow on this picture 

Randomly watching a YouTube video on a different issue the bloke mentioned the blue path is the overflow from the float chamber so I am suspecting an issue with the needle valve causing high float chamber level and then potentially overspill fuel spilling down those jets 

Rather than just try tapping it free with a rubber mallet I thought I'd better take a look inside the chamber, unfortunately on these carbs you can't just get the lid off the whole carb has to come off, although it did give me the opportunity to see there's no gasket on one side of the mounting block and not much of one on the other side 

from the first part of this thread I knew @spartacushad had the carb off and cleaned it, and then on collection day @Grumblespeedand I had also had the float chamber open for cleaning so wasn't expecting anything too bad muck wise and so it proved

I got a better chance to check the accelerator jet too which isnt so easy to see when the carb is together and it produces a health spray so no issue there . The float chamber was pretty full though, not sure how full its supposed to be but it was almost to the top

I couldn't get the float pin out so wanted to double check which way it comes before trying to force it out but did try and see if the valve was sticking. It doesn't appear to be but not sure it looked like it was quite right. Are they supposed to open/move that much.  Only other carb I've taken apart on my Estelle didn't seem to open so wide/move so much from memory 

any thoughts welcome 

 

 

[Mr Pastry]

The float won't drop down so far when installed, as it would hit the the bottom of the chamber if it is empty, and of course should float otherwise.

 Worth checking the float height if the book gives a procedure for that, but it is rare for them to need adjustment

IMO your lack of gaskets is a more likely source of trouble.

 

[wesacosa]

hmm true on the float height but it definitely was overflowing 

[Mr Pastry]

1 minute ago, wesacosa said:

hmm true on the float height but it definitely was overflowing 

Does it close under air pressure if you blow into the inlet pipe?

[wesacosa]

12 minutes ago, Mr Pastry said:

Does it close under air pressure if you blow into the inlet pipe?

Hmm haven't tried. would it be expected to close if you blow it? Interestingly the carb didn't seem to respond when I sprayed wd40 around the missing gasket area previously 

[Mr Pastry]

Sorry, I mean if you hold the float up so the valve closes, will it seal if you blow into it?  Fuel pressure is only few psi so it doesn't need much pressure to test it.  It may tell you something. 

[wesacosa]

8 minutes ago, Mr Pastry said:

Sorry, I mean if you hold the float up so the valve closes, will it seal if you blow into it?  Fuel pressure is only few psi so it doesn't need much pressure to test it.  It may tell you something. 

ah ok gotcha. will try that 

Guess it could maybe have been stuck but freed off when I took it apart . Either way I guess it needs a refresh kit anyway which will come with a new needle valve 

[wesacosa]

I seem to be finding new and exciting ways to break it. Not good as its on the drive still and Mrs W is starting to give me a really hard time.

I decided to treat it to a partial carb refurb, I didn't take the bottom throttle body part off not the rear vacuum servo bit but I did all of the other seals and gasket and the accelerator pump diaphragm and the front (power??) diaphragm 

However its still running quite badly, possibly worse. As you can see from this video it stumbling and hesitating when you open the throttle quickly 

https://youtu.be/0Uj7vl4CpGw?si=jVnDWM2JDK1c3v8v

 Ialso went to double check the timing and whilst it seems ok with the vacuum hose off and plugged, with the vacuum advance connected the timing is jumping wildly cycle to cycle as you can see in this video 

https://youtube.com/shorts/alMPa_Z1j6w?si=YL00Tj6r9GMhvl9H

Ignore the absolute timing as I played around with the advanced dial to bring it into the window. There are no holes in the hose and the vacuum advance is new and was working ok before I started messing with the carb.  I sprayed all around the carb with wd40 and couldn't see any sign of an air leak. 

Really should have left well alone until it was MOTd and taxed and off the drive but hey ho where's the fun in that

 

too much hissing?

 

[Mr Pastry]

3 hours ago, wesacosa said:

too much hissing?

To me that just sounds like normal induction hiss.  If there is a small vacuum leak you probably wouldn't hear it.  If it runs alright with the vac advance blanked off then it's probably good enough to get you to an MOT and back.  Set the timing statically to the marks and leave it at that. 

 

[wesacosa]

8 hours ago, Mr Pastry said:

To me that just sounds like normal induction hiss.  If there is a small vacuum leak you probably wouldn't hear it.  If it runs alright with the vac advance blanked off then it's probably good enough to get you to an MOT and back.  Set the timing statically to the marks and leave it at that. 

 

Not sure it runs ok with the advance off but it stays reasonably on its timing marks but the timing bounces all over the place with it connected 

[Mr Pastry]

I'd be happy to have a look at this if I was closer, but I'm 180 miles away.   So I may not be suggesting quite the right things, based on your info.

The vacuum advance should not be doing anything at idling speed with no load.  

The static timing needs to be correct first, and carb set to idle with choke off at 8-900 rpm, or whatever the book says.  You need to achieve that first

Then with vac advance blanked off, if you rev the engine to say 1500 the centrifugal advance should operate and the timing light should show that.

 

[wesacosa]

51 minutes ago, Mr Pastry said:

I'd be happy to have a look at this if I was closer, but I'm 180 miles away.   So I may not be suggesting quite the right things, based on your info.

The vacuum advance should not be doing anything at idling speed with no load.  

The static timing needs to be correct first, and carb set to idle with choke off at 8-900 rpm, or whatever the book says.  You need to achieve that first

Then with vac advance blanked off, if you rev the engine to say 1500 the centrifugal advance should operate and the timing light should show that.

 

Cheers 

The static timing and timing with the vacuum advance disconnect and hose plugged is ok,  then bringing the revs up advances the timing so mechanical advance is ok

The problem is , before I messed with the carb when you reconnected the vacuum advance at idle it advanced to about 15deg which is what I believe it's supposed to do.  The problem now is that since I messed with the carb when I connect the vacuum advance the timing starts jumping around erratically 

I think you can hopefully see it on this video with the white tippex mark jumping around in the timing window 

surely this must be a vacuum issue?

I will try and get a vacuum gauge teed into the line to see if the reading is stable 

 

 

[Mr Pastry]

27 minutes ago, wesacosa said:

I will try and get a vacuum gauge teed into the line to see if the reading is stable 

Yep clearly worth doing.  IIRC you have had the dizzy apart, is the vacuum advance operating freely at that end?

 

[Westbay]

Diaphragm in vacuum advance split/holed ?

[wesacosa]

17 minutes ago, Mr Pastry said:

Yep clearly worth doing.  IIRC you have had the dizzy apart, is the vacuum advance operating freely at that end?

 

Interestingly it seems to be working this morning. I took the hose off, tried operating it with my hand vacuum and sucking on the hose and when it went back the timing seems ok

this is actually with no correction on the timing gun so its running reliably at the 15 deg it should be

Its still a bit coughy on first throttle blip though, Looking at the accelerator jet there is fuel coming out but wondering if it should be so dribbly or if it should be more of a jet

 

8 minutes ago, Westbay said:

Diaphragm in vacuum advance split/holed ?

I'm hoping not as its only been on about 1000 miles but I know they can be problematic but as per above the timing seems ok today