Idling

[Angle Grinder]

Developed an idling problem very suddenly today on my Solex carb 1800 Coupe. Car started and idled without any issues and was driven ~20 mins with no problems. Sat for an hour, then restarted warm without any choke... drove for ~3 mins then stalled at a junction, but re-started OK. Idling then rapidly worsened until I could only keep her idling by applying quite a lot of choke and this was with a fully warmed through engine.

The suddeness of the problem with the idling suggests to me that it might be dirt in the Idle Jet, but I have only got experience of Weber carbs so was hoping for some tips on what I could / should be checking and cleaning on a Solex carb.

This morning when warming up, she was ticking over without complaint at ~700 - 900 rpm

Found quite a good article on another website, but wasn't sure how much commonality there is between this model of Solex carb and the versions fitted to Flavias.
http://www.mbzponton.org/valueadded/maintenance/carb3/idle.htm

I've checked all the hose pipes around the servo and there's no loose clamps or obvious air leaks in that area.

Hope you can help.

[lancialulu]

I have the same issue with my Flavia (1800 carb). Starts well, idles well, dies at junction (sometimes just picks it self up...).

Was like it when I bought it and was told maybe some dirt in the idle circuit. So I got a carb recon kit and rebuilt a totally clean carb. No change.

Then found the timing was way out. Re adjusted and it seemed to make a difference, but yesterday was same again dying at junctions. I had tweaked the mix to get beautiful smooth idle on the driveway but have resolved to richen a bit to see if this cures the dying bit.

Would welcome more input to this issue.

[Richard Fridd]

I have had the idle jet block on one bank of cylinders of my Flaminia, which only slightly affects the tickover, but is certainly noticable once 'on the move' up to 3000 rpm Lots of 'red herrings' investigated, but always that idle jet. Richard

[Brian Long]

Humber Vogues and Sunbeam Alpines used the same Solex carb . The workshop manual gives a very good description of how to unblock jets without removing the carb.
Also fit a good petrol filter.
Brian Long

[Angle Grinder]

Humber Vogues and Sunbeam Alpines used the same Solex carb . The workshop manual gives a very good description of how to unblock jets without removing the carb.
Also fit a good petrol filter.
Brian Long

So can you give us a clue what the workshop manual suggests, as my workshop manual for the Flavia doesn't give any tips on the Carb other than how to take it fully apart!

My Carb is not the original model fitted to the car (according to the service history) and I have two jets on the back of the carburettor body that are presumably part of the idle circuit. Have not yet removed them to blow them through as I was hoping to get some guidance from the forum.

[lancialulu]

The left hand jet at the back is the idle. The right hand is for the other choke.

I dont have a manual but will chase down the humber etc. Info.

Brian any chance you could scan those pages?

Tim

[Angle Grinder]

have fixed it  

Took out both of the jets liberally sprayed with carb cleaner, huffed and puffed and drank a cocktail of carb cleaner / petrol (daren't burp now in case I explode)  . Refiited with a new fuel filter and all seems happy now! Or at least it seems OK after being run up to temp and driven in and out of the garage a few times!

Next job is to sort out the old rubber bushes between the front subframe and chassis. Anyone got experience of this? Can it be done without completely dropping the subframe?

[Richard Fridd]

If anything like a Fulvia, slacken/remove subframe bolts with bodyshell jacked up, making sure hoses, wiring and control cables have adequate free length. Probably worth oiling the captivated nut threads from the top first. If refitting the bolts becomes tricky, ensure the captivated nuts are still in their cages, and properley positioned. Richard

[Angle Grinder]

Almost a year later and I'm having this problem again.

Developed an idling problem very suddenly today on my Solex carb 1800 Coupe. Car started and idled without any issues and was driven ~20 mins with no problems. Sat for about 90 mins, then restarted warm without any choke... drove for ~10 mins then stalled at a junction, but re-started OK. Idling then rapidly worsened until I could only keep her idling by applying quite a lot of choke and this was with a fully warmed through engine.

I've removed both the jets and blown them through with carb cleaner and with good old fashioned lung power. Hard to gauge if I cleared anything out of them or not.

I haven't changed the fuel filter this time, but it is only a year old and probably only sucked "400 miles" of fuel through it!

I can get the engine to fire and can hold an idle with a lot of choke, but if I close the choke she dies unless given throttle. What I have noticed is that I get a "pop" on closing the throttle after gunning it.

The car has always been a bit poppy on the over-run, but never used to "pop" instantly when the throttle was snapped shut.

Please excuse my ignorance of Solex carbs and points, I grew up with digiplex ignition management and fuel injection! 

[Richard Fridd]

A weak mixture? Perhaps an air leak. Gasket or servo hose leak?

[Angle Grinder]

Maybe Richard, but I took the fuel filter off and the side that I couldn't see when en-situ was pretty nasty so I'll try a new fuel filter tomorrow and see how it goes from there.

[lancialulu]

My 1800 had an idling problem of starting fine, idling fine in the drive but stalling at every junction. I stripped and serviced the Solex carb and checked everything, and put a new inline see through filter in place (there was no dirt in the old one, just being careful). Same thing. Beatiful idle in drive but stalling at every juntion. After a few irritating trips out I decided it was the idle circuit but could see anything wrong.

So I adjusted the idle mix off optimum to slightly richer which dropped the tickover so I had to up that at tad. I thought if the car got really hot it would give me a racing idle, but I decided to try it. Now the car still starts well, idles when cold and does not stall at junctions! Nor is it lumpy, and I can report that over 300 miles of stop start and thrash miles the car did not stall once nor raced at idle. It seems this Solex has a weird idle circuit.....

Try richening the idle mix....

[Angle Grinder]

Easy fix... it was just a case of fitting a new fuel filter and blowing through the idle jet. Purring sweetly now. 

[DavidLaver]

Great news.

[peteracs]

Easy fix... it was just a case of fitting a new fuel filter and blowing through the idle jet. Purring sweetly now. 

Given only 400 miles on this filter, does this imply something nasty in the fuel tank? Maybe worth draining/inspecting to see what comes out etc?

Peter