Solex Carby

[101RRS]

This relates to my Haflinger but I will post here as it is a carby issue and the carby is similar to that on a spreadbore 2 litre.

My Haflinger has a Solex 34 PCI carb which is very similar to the Solex 32 (?) on series 1s so the issue I am having might be similar on landies.

Basically when going up steep hills and you are in too high a gear and revs drop off (it is almost impossible to go from second gear to the krawler 1st gear on the move in a Haffie) it feels as if the the engine over fuels and then dies and will not start on the slope so you have to back down to get level. If you are in the right gear and revs are kept up - on a Haflinger this means over 2000rpm there are no issues irrespective of the slope - so I think the issue relates to too much fuel at low revs on slopes.

Otherwise the engine runs fine.

Any ideas on what I should be looking for - eg float levels, mixture adjustment etc

The engine has a big bore kit in it so it 762cc instead of the normal 635cc and the Zenith dual throat carby has been replaced with the solex and an electronic ignition system with a coil pack is fitted. The mechanical fuel pump has been ditched in favour of an electric unit.

Thanks

Garry

[series1buff]

Hi

it could be because the float chamber is pointing towards the wrong side e.g., if you read the Solex booklet Mark posted a link to


http://vintagebus.com/parts/pdfs/solex.pdf


- it states that the float chamber should be on the forward /front end of the vehicle . Flooding can occur during uphill driving if the float chamber is not oriented correctly .

Mike

[101RRS]

Hi

it could be because the float chamber is pointing towards the wrong side e.g., if you read the Solex booklet Mark posted a link to


http://vintagebus.com/parts/pdfs/solex.pdf


- it states that the float chamber should be on the forward /front end of the vehicle . Flooding can occur during uphill driving if the float chamber is not oriented correctly .

Mike

Thanks - the float chamber is orientated the same as the landie - towards the front of the vehicle.

Cheers

Garry

[bee utey]

Funny I was talking about odd carby problems the other day, has your carby got a warm air feed? In cool damp conditions the idle air corrector jets can ice up and cause it to run rich until warmth gets back into the carb top. I used to have endless troubles with an off road dune buggy on cold nights doing that. I made a warm air feed off the exhaust manifold for it.

[101RRS]

has your carby got a warm air feed?

Yes the two exhaust manifolds are joined by a large pipe that the carby sits on so keeping it nice and warm on cold days.

Cheers

Garry

[bee utey]

Yes the two exhaust manifolds are joined by a large pipe that the carby sits on so keeping it nice and warm on cold days.

Cheers

Garry
Most carbies are fitted to heated manifolds, essential for operation at load, I meant is the air going into the top of the carby heated?

[101RRS]

Sorry - misunderstood - no the air is not heated - currently sucking air from inside the engine bay - will be a bit warmer than ambient due to heating of the air in the engine compartment from the engine.

Garry

[Hartley]

is it mechanical fuel pump? Perhaps starves fuel at times of higher demand if you run with low revs?

[101RRS]

is it mechanical fuel pump? Perhaps starves fuel at times of higher demand if you run with low revs?

That is a problem that does happen with the standard mechanical system but mine has an electric pump. The pump is able to provide enough fuel at all revs.

In fact it feels as if I have the opposite issue - at low revs, high load the engine seems to be overfuelling and stalling the engine. Maybe the float is set too high but is OK on the flat but on the slope the excess fuel is flooding the engine - not a problem when revs are high as the excess is used up but at slow revs with the foot down.


I was hoping someone with a series 1 may have experienced a similar issue and found the cause.


Here is a vid of the issue - I had to back down the hill to a flatter spot and then the engine slowly came back to life - seemed like it was flooded. I then engaged the krawler gear and did the climb ok - just a bit noisy and high revs.


http://i42.photobucket.com/albums/e334/gazzz21/Forum%20Posts%20Album/EngineStopping_zpsf4da9a0e.mp4

[wrinklearthur]

Secure that vehicle where it has stopped and jump out quickly as you can, undo the fuel cap listening for a inward rush of air.

If the tank breather isn't working the vacuum inside the tank reduces to the point the fuel pump stops drawing.
.

[wrinklearthur]

The toss of the vacuum problem, still with a blocked breather is the build up of tank pressure causing the fuel to push past the needle and seat before they close tight.
Check that again by getting to the fuel cap quickly when the vehicle stops and listen for a outward rush of air when undoing the fuel cap.
.

[101RRS]

I am still having these problems which I have not been able to resolve. Since my last post the car has been looked at by a carby expert and supposedly all is OK but the spark plugs are still sooted up so looks to be still running rich.

Went for a drive up a steep hill nearby (Black Mountain in Canberra) and the engine kept on loosing power - foot flat to the floor and it would start loosing power - backing off made things run a little better but when the engine died it would fire but not run - pointing downhill and all was fine. Engine runs fine on the flat and moderate hills but not steep hills.

The Carby is laid out the "right way" as in the top right diagram when going up hill.

http://i42.photobucket.com/albums/e334/gazzz21/Forum%20Posts%20Album/SolexCarby_zps334c29d7.jpg (http://s42.photobucket.com/user/gazzz21/media/Forum%20Posts%20Album/SolexCarby_zps334c29d7.jpg.html)

My thoughts are that the engine is getting too rich when going up hill. So on the Series 1 32mm version of the carb, how do you adjust the float levels as I am thinking mine is a little too high. The floats in both carbies do not seem to have adjuster tabs. Also can anyone advise the psi that the series 1 fuel pump runs at - the electric pump I have may have too high fuel pressure.

As this carb is not the correct carb for the engine I have decided to get rid of it and get an original which is not easy to find. The closest is a carby off a Unimog 404 which I have purchased and it is in the mail to me. Should just need a kit and some rejetting.

Appreciate comments from the Series 1 Solex experts.

Cheers

Garry

[chazza]

According to a scan Mike from Gippsland posted years ago, the fuel pressure must be between 1 1/4 psi to 2 1/2 psi.

It appears from the article, that the float level is not adjustable as you found out. Check that the float arm is not bent or the float punctured,

Cheers Charlie

[wrinklearthur]

On level ground after running the engine, first disconnect the fuel line, then carefully lift the top of the carby and measure the distance between the fuel and the top edge of the float chamber.

.

[101RRS]

On level ground after running the engine, first disconnect the fuel line, then carefully lift the top of the carby and measure the distance between the fuel and the top edge of the float chamber.

.

Thanks - will do that but what then :). What sort of difference in height between the two levels should there be and if it is not right what can be done to adjust the level?

Cheers

Garry

[wrinklearthur]

Originally Posted by wrinklearthur
On level ground after running the engine, first disconnect the fuel line, then carefully lift the top of the carby and measure the distance between the fuel and the top edge of the float chamber..


Thanks - will do that but what then :). What sort of difference in height between the two levels should there be and if it is not right what can be done to adjust the level?

Hi Garry

Is this picture the same as your carby?
https://www.aulro.com/afvb/images/imported/2013/09/1564.jpg

By getting your measurement, we can then compare the specifications for that model carburettor, if the fuel level in the float bowl is found to be about right, then maybe either the throttle body and/or the jets would need changing.

Another couple of measurements that would be handy, are the manifold vacuum levels at a range of revs at working temperature.

If the inlet manifold isn't at the correct working temperature, then the petrol wont vaporise properly either and this shows up on the spark plugs as a sooty deposit.
.

[101RRS]

.Is this picture the same as your carby?
https://www.aulro.com/afvb/images/imported/2013/09/1564.jpg

By getting your measurement, we can then compare the specifications for that model carburettor, if the fuel level in the float bowl is found to be about right, then maybe either the throttle body and/or the jets would need changing.

Another couple of measurements that would be handy, are the manifold vacuum levels at a range of revs at working temperature.

If the inlet manifold isn't at the correct working temperature, then the petrol wont vaporise properly either and this shows up on the spark plugs as a sooty deposit.
.

Thanks - yes that is the carby.

Unfortunately not in a position to check manifold vacuum levels as I don't have any gear that can do that.

Heating of the inlet manifold is via a pipe that directs a small amount of exhaust gas from one exhaust port to the other and heats up a plate that the carby sits on. I will get my laser temp reader and see what temp it gets up to after the engine warms up. However as I indicated the engine runs fine in normal use - just plays up on steep uphill climbs.

I will get post up my checks probably tomorrow.

I appreciate you input - thanks

Garry

[Blknight.aus]

you have an emulsification, float or vent problem on the main fuel bowl.

when the throttle snaps shut the increase in vac is drawing excess fuel down the throat and flooding you out.

I have a manifold vac gauge you can borrow.

[101RRS]

you have an emulsification, float or vent problem on the main fuel bowl.

when the throttle snaps shut the increase in vac is drawing excess fuel down the throat and flooding you out.

I have a manifold vac gauge you can borrow.

Dave - thanks for you input but the issue is happening when the throttle is open powering up a hill not closed, however I do agree that excess fuel is going down the throat and flooding the system.

My understanding of a manifold vacuum gauge is that it needs to have access to the manifold after the carby or at its base - in my case there are no ports like say there are on a Rover V8 manifold- the manifold is just a piece of mild steel pipe with a plate welded on where the carby is bolted. I guess I could drill a hole into it and create a port but at this stage I would prefer not too.

A general question - seeing there is no adjustment on the float - what would happen to general drivability (noting it is flooding on hills) if I effectively lowered the float level and hence the amount of fuel in the float chamber by soldering a bit of solder on the float arm where it lifts the float needle.

Cheers

Garry

[wrinklearthur]

Dave - thanks for you input but the issue is happening when the throttle is open powering up a hill not closed, however I do agree that excess fuel is going down the throat and flooding the system.

My understanding of a manifold vacuum gauge is that it needs to have access to the manifold after the carby or at its base - in my case there are no ports like say there are on a Rover V8 manifold- the manifold is just a piece of mild steel pipe with a plate welded on where the carby is bolted. I guess I could drill a hole into it and create a port but at this stage I would prefer not too.
Does the Haflinger have a vacuum line going to the distributor? may be able to do a tee off that line.


A general question - seeing there is no adjustment on the float - what would happen to general drivability (noting it is flooding on hills) if I effectively lowered the float level and hence the amount of fuel in the float chamber by soldering a bit of solder on the float arm where it lifts the float needle.
Best if doing the soldering thing is to sweat a brass pad on top of the float as 50/50 solder is too soft and would wear too quickly.
Another way is to fit a extra washer to drop the needle valve down a bit.

What condition is the float in and is it out of round at all ? As it may be sticking and not be able to close the needle valve off.
Without going back through the thread to find out if it was replaced, the needle valve if worn may be sticking or not seating properly.
.

[chazza]

Garry; I think I might have the answer. In the PDF I sent you it explains that;
"... it is possible by selection of air and petrol jets to supplement the main petrol mixture... allows the size of the main jet to be chosen thus... avoids over-richness at full-throttle low revolutions...

My guess is that your carburettor has been jetted for a much larger displacement engine, and essentially it is flooding when you change gear on a steep hill i.e. full throttle, low speed, low revs.

The answer perhaps, is to experiment with different emulsion tubes; and the petrol jet labelled Ep in the diagram I sent you. The bad news I suspect is that Solex parts are hard to find and you may not be able to get them; try Gower and Lee, UK,

Cheers Charlie

[Blknight.aus]

Dave - thanks for you input but the issue is happening when the throttle is open powering up a hill not closed, however I do agree that excess fuel is going down the throat and flooding the system.

My understanding of a manifold vacuum gauge is that it needs to have access to the manifold after the carby or at its base - in my case there are no ports like say there are on a Rover V8 manifold- the manifold is just a piece of mild steel pipe with a plate welded on where the carby is bolted. I guess I could drill a hole into it and create a port but at this stage I would prefer not too.

A general question - seeing there is no adjustment on the float - what would happen to general drivability (noting it is flooding on hills) if I effectively lowered the float level and hence the amount of fuel in the float chamber by soldering a bit of solder on the float arm where it lifts the float needle.

Cheers

Garry

theres always adjustment on the float, just sometimes you need to be a bit agricultural about it....

my bad, i read the original question to mean that it died off once you closed the throttle to downshift.

second in a halfie just about climbs trees as is I dont want to see the hill that you need crawlie gear in an empty halfie to get up...

might also help to check the timing, if thats walked a bit you can get some interesting issues.

[101RRS]

On level ground after running the engine, first disconnect the fuel line, then carefully lift the top of the carby and measure the distance between the fuel and the top edge of the float chamber.

.


According to a scan Mike from Gippsland posted years ago, the fuel pressure must be between 1 1/4 psi to 2 1/2 psi.

Cheers Charlie


Garry; I think I might have the answer. In the PDF I sent you it

Cheers Charlie


theres always adjustment on the float, just sometimes you need to be a bit agricultural about it....

my bad, i read the original question to mean that it died off once you closed the throttle to downshift.

might also help to check the timing, if thats walked a bit you can get some interesting issues.

My apology - I thought I had responded to you all on this last week but it seems I forgot to hit the "submit" icon :(.

Charlie - thanks for the PDF great information - though I am not in a position to tinker with internals of the carby and there seems there are no experts locally.

Thanks for the PSI numbers - would seem to be correct. My car has a Facet 480616 pump and when I tried to find the specs of this I could not find any but similar pumps are running 6-8 psi so if this is so I started thinking that when the float it is a high angle the higher pressure maybe pushing past the needle.

So I have put in a replacement pump that is rated 1.5-3.5psi. This seemed to have a positive impact as I was able to drive up the big steep hill without it dying (still with a miss though) - was able to pull one higher gear for most of it and up to 10kph faster - so was part of the issue.

Arthur - I parked up on the flat and pulled off the top of the carby. (I was surprised at the amount of fine carbon around the air inlet of the carb.

http://i42.photobucket.com/albums/e334/gazzz21/Forum%20Posts%20Album/2013-09-11_21-33-53_784_zps25f8c93b.jpg (http://s42.photobucket.com/user/gazzz21/media/Forum%20Posts%20Album/2013-09-11_21-33-53_784_zps25f8c93b.jpg.html)

The fuel level was only half was up the fuel chamber with the float in
http://i42.photobucket.com/albums/e334/gazzz21/Forum%20Posts%20Album/2013-09-11_21-41-34_218_zps69d21eb9.jpg (http://s42.photobucket.com/user/gazzz21/media/Forum%20Posts%20Album/2013-09-11_21-41-34_218_zps69d21eb9.jpg.html)

And with the float removed only about 1/3 up the fuel chamber (near where it changes diameter - the dirt is not dirt but previous corrosion)
http://i42.photobucket.com/albums/e334/gazzz21/Forum%20Posts%20Album/2013-09-11_21-42-49_507_zps27de95b5.jpg (http://s42.photobucket.com/user/gazzz21/media/Forum%20Posts%20Album/2013-09-11_21-42-49_507_zps27de95b5.jpg.html)

So to my untrained eye this level would seem to be OK - I am not sure what the level would have been with the old higher pressure pump. I am going to put on a different carby top, float and needle and see how that goes.

Dave - I adjusted the idle up and that has also helped the gear change on steep hills.

On the ignition of ignition - it has an fully electronic aftermarket system that has 16 maps inbuilt - there are not weights or vacuum advance as all of this is done by the system. I have statically reset it, so it is firing as designed however:

The standard dizzy has 0 advance at 850 revs, 10.5 degrees advance at 2000rpm, 21.2 degrees at 3000rpm and 26.8 at 4000rpm.

I am not sure what map is actually set on the electronic ignition as I have not wanted to play with it at this stage but typical figures are:
0 at idle, 16.8 at 2000rpm and 28 at 3000rpm. Other specialist maps range from 17 to 24 at 2000rpm and 26-32 at 3000rpm.

So you can see the electronic maps are far more advanced than the standard map - I am not sure if this is an issue but on occasion on starting it can want to try an fire backwards but does not - the engine does not ping or run any differently on 91, 95 or 98 RON.

On the road a Haflinger is a vehicle that is run flat out - the engine red lines at 4800rpm and when driving the engine is normally above 4200rpm all the time. The spread of gear ratios is not good and are more offroad orientated with max speed in fourth is 40kph so when in 5th and hitting a hill it starts dying but you have to wait until speed has dropped from say 60 or 70 to 40 before you can change down.

They are a horrid machine to drive onroad (you feel extremely vulnerable) but fun offroad :).

Why do I post my Haffie questions on a Landrover Forum - because I get great answers here, where on the other relevant forums I don't get much of a response.

So I appreciate your input and help.

Cheers

Garry

[101RRS]

Well I will be .............

I have three parts carbies in my spare parts bin. I took the top of one and noted that the choke was a little different and it had a different needle and seat so I put this carby top, needle and seat and float into my carby.

All of a sudden the engine no longer seems strangled, I was seeing a GPS speed of 80kph where I would normally only see 70 and I when i went to the big hill up Black Mountain it would now pull it in 4th gear and 40 kph and once into top where before it was 3rd most of the way and 25kph - no hesitation and no missing.

So my guess the issue was, too high fuel pressure combined with a dodgy needle.

Now need to get the mixture sorted as it is still rich.

Cheers

Garry

[chazza]

Nothing like a good news story to start the day!:D

Have you tried Gower and Lee yet?

Cheers Charlie

[101RRS]

Hi Charlie - no not contacted them yet though I have them bookmarked and looked through their site.

I am not really competent to play around with the real innards of the carby and would prefer a competent person to do so if I could find one.

Now that it seems to be running OK I am going to leave it alone.

I cannot get the correct Zenith carby but have purchased a Unimog version which when rejetted is a match for the correct carby. There is a place in Melbourne that can rebuild this for me.

My inlet manifold was modified to take the Solex carby I currently have so I will have to get a new manifold which will not be easy or get one made. But all that will have to wait a while.

Cheers

Garry