- Thread starter petak
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petak
Enthusiast
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Long time no response...
Juddering is history but i am still not satisfy how car work.
It spend to much petrol..... 6,5 to 7 liters per 100km. (34 to 36 mpg)
Exhaust pipe is black. It smell heavy on petrol and car has lost his acceleration.
Definitly there is problem with carb.
It looks like it does not react when i turn mixture screw.
Hope to get it on exhaust analisator to see what is happening but i must open one of my carbs and see if i can do something.
Repair set ordered already.
Now something better .
Todays job....relocating on old olive three....
She (olive three).....my father.....my brother....and faithful friend
Juddering is history but i am still not satisfy how car work.
It spend to much petrol..... 6,5 to 7 liters per 100km. (34 to 36 mpg)
Exhaust pipe is black. It smell heavy on petrol and car has lost his acceleration.
Definitly there is problem with carb.
It looks like it does not react when i turn mixture screw.
Hope to get it on exhaust analisator to see what is happening but i must open one of my carbs and see if i can do something.
Repair set ordered already.
Now something better .
Todays job....relocating on old olive three....
She (olive three).....my father.....my brother....and faithful friend
André4Renaults
Enthusiast
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- 753
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- Barnet, Hertfordshire.
It seems your engine is running too rich, meaning it is burning too much petrol all the time. Check that the choke control is working properly and when it's pushed fully in the choke valve is fully off. An exhaust analyser will tell you at what percentage CO the car is running. There will be a correct setting, probably about 3.5% (the setting will available on autodata) and once you know it you can adjust it to the correct setting.
JonathanT
Not normal for Norfolk
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That's a great photo Petak. Looks very stony there but warm! We've had snow today .
Shame about the carb problems . There is /was a new Solex one on eBay uk
new Carburettor Fit for Renault R4 GTL 1961-1992 Carburetor SOLEX MODEL 32 DIS
Shame about the carb problems . There is /was a new Solex one on eBay uk
new Carburettor Fit for Renault R4 GTL 1961-1992 Carburetor SOLEX MODEL 32 DIS
mojobaby
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Hi Andrew
I'm glad that you brought this subject up. I have the same problem as Petak. Black spark plugs and black exhaust
Am I correct in saying that the mixture screw on a Zenith 28IF only works for the mix at idle? I read it somewhere on this forum.
How else can the mixture be regulated besides at the choke flap. Could it be that my spark plugs aren't burning the fuel correctly? They're about 2 years old but haven't done a lot of mileage on them.
Appreciate any help, as would Petak, I'm sure!
petak
Enthusiast
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- Vodice, Croatia
Yes Andrew....it is to rich but i do not know what to do! I have set choke as it is described in carburetor manual.
pdf is attached to this post
Also it seems that body of the carb is wet from petrol......as somewhere is leaking petrol .....can not tell for sure.
But carb was nice and shinny when i put it in few months ago and few days back i noticed "moisture" on my fingers below carb body.....where chamber for float is.
Last year at MOT exahust fumes were
CO - 2,593%
CO2 - 11,16%
HC - 566ppm
O2 - 3,72%
Only CO must be below 3,5% to pass
This is not same carb on car
This week i have MOT again and will find out number but would like to get to carb work smooth and nicely
JonathantT....Thank you for comment...you can bump into stone here and there If you are very lucky
Yesterday was nice day. some 6-7°C in shade but on sunny parts it was even warmer. Nice day for agriculture.
Do you have feedback for those HONG KONG carburetors?7
I believe they are copy!
Mojobaby.... i do not mind.....as this conversation is opened for all parts interested in, and every small detail can help me too ......carb it is really "black box" to me and would like to find out how to tune it up on my own, as there are no more mechanics (at least here where i am) who can do that job.....I know one in Zagreb but it is 350km one way and i need to left him car for at least one day so he can set carb properly. If nothing else works i will drive to Zagreb and let him do the job.
pdf is attached to this post
Also it seems that body of the carb is wet from petrol......as somewhere is leaking petrol .....can not tell for sure.
But carb was nice and shinny when i put it in few months ago and few days back i noticed "moisture" on my fingers below carb body.....where chamber for float is.
Last year at MOT exahust fumes were
CO - 2,593%
CO2 - 11,16%
HC - 566ppm
O2 - 3,72%
Only CO must be below 3,5% to pass
This is not same carb on car
This week i have MOT again and will find out number but would like to get to carb work smooth and nicely
JonathantT....Thank you for comment...you can bump into stone here and there If you are very lucky
Yesterday was nice day. some 6-7°C in shade but on sunny parts it was even warmer. Nice day for agriculture.
Do you have feedback for those HONG KONG carburetors?7
I believe they are copy!
Mojobaby.... i do not mind.....as this conversation is opened for all parts interested in, and every small detail can help me too ......carb it is really "black box" to me and would like to find out how to tune it up on my own, as there are no more mechanics (at least here where i am) who can do that job.....I know one in Zagreb but it is 350km one way and i need to left him car for at least one day so he can set carb properly. If nothing else works i will drive to Zagreb and let him do the job.
André4Renaults
Enthusiast
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- 753
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- Barnet, Hertfordshire.
Hi Andrew
I'm glad that you brought this subject up. I have the same problem as Petak. Black spark plugs and black exhaust
Am I correct in saying that the mixture screw on a Zenith 28IF only works for the mix at idle? I read it somewhere on this forum.
How else can the mixture be regulated besides at the choke flap. Could it be that my spark plugs aren't burning the fuel correctly? They're about 2 years old but haven't done a lot of mileage on them.
Appreciate any help, as would Petak, I'm sure!
The way I would attempt to sort this would be to start with the electrical side of things; confirm the points are correctly set to the right gap and that they are correctly timed. A good strobe lamp can help, as this will give a dwell angle, which is more accurate than using feeler guages to set the point gap. Then check the spark plug electrode gap & confirm the plugs are clean and not oiled up-clean or replace if necessary. Take a look at the H.T. leads and assess their condition; if they're old, brittle or show signs of rubbing change or replace. Don't forget the coil lead, too!
Now the carburettor. Check the choke cable goes fully home when the control on the dashboard is pushed fully in. I adjust these so that the control is slightly "proud" and then you know the flap in the carb is FULLY home when it's pushed in. If the action seems sticky or stiff oil the cable linkage by dribbling a little 3 in 1 oil down inside the cable and do the same to the accelerator linkage if it feels similarly stiff or sticky.
Check the air filter for condition and clean out the housing of leaves etc. Change the air filter if necessary. make sure the intake is set for winter or summer, as appropriate. While looking into the top of the carb give the choke cable a few "pushes and pulls" and ensure that the butterfly isn't sticking in the throat of the carb.
Check the oil level and assuming all's well, switch on & allow the motor to reach normal operating temperature. Once it has, and the choke is pushed fully in (so it's off) WITH THE CAR IN NEUTRAL use the idle screw to raise the tick-over speed slightly. (If you're not sure which screw it is, it's the one that moves the cam that attaches to the accelerator cable.) Now, with the tick-over running a liitle higher then it normally would screw the mixture screw fully into the carb, but do it gently and do not force anything! The car will start to sound "lumpy" and as you begin to unscrew the mixture the tick-over will rise (usually 1.5 to 2 turns will be about right) and the car will sound "happier." Now reduce the tick-over using the idle screw and rev the car a few times. It should rev up without any hesitancy or "gasping" for air. If it sounds OK take the car for a run & see how it feels on the road.
These adjustments are not an EXACT science with cars of the age of ours, and settings may vary from what I've suggested. All adjustments to the mixture & tick-over are done when the engine is at idle, though.
In the UK a decent classic-friendly garage would probably do the adjustments described above during the M.O.T. test for a small additional charge. I did loads of them when I did tests, as it saved time; failing the car, only to have the owner go away , bring it back and then having to couple it up to the exhause analyser took longer then re-setting things there and then!
Sorry to have gone on a bit, but I hope it helps!
mojobaby
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Thanks Andrew, that sounds pretty straight forward.
The tester at my MOT tried to help and screwed the mixture screw completely in. I could see he used a lot of force and when I removed it at home, I noticed that the point was damaged. I used a very fine sandpaper to smooth off the hook at the point and it seems to be OK.
Its currently one turn outwards.
You haven't mentioned the choke butterfly flap at the base of the carb. There's a setting for that as well, 0,60 to 0,80mm. It's adjusted by the rod on the front of the carb. I've recently set that gap as I found it closed, but its too soon to see if its made any difference. The car certainly seems to start quicker in the mornings!
Presumably that gap should be set first before the idle screw is turned in?
The tester at my MOT tried to help and screwed the mixture screw completely in. I could see he used a lot of force and when I removed it at home, I noticed that the point was damaged. I used a very fine sandpaper to smooth off the hook at the point and it seems to be OK.
Its currently one turn outwards.
You haven't mentioned the choke butterfly flap at the base of the carb. There's a setting for that as well, 0,60 to 0,80mm. It's adjusted by the rod on the front of the carb. I've recently set that gap as I found it closed, but its too soon to see if its made any difference. The car certainly seems to start quicker in the mornings!
Presumably that gap should be set first before the idle screw is turned in?
André4Renaults
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OUCH! The mechanic should NOT have used that much force on the mixture screw and sandpapering it is not recomended, as you may have damaged the jet, but needs must.... As to the butterfly flap at the base of the carb, I think the setting you refer to is the one that allows fuel in when the choke is on, so setting it properly will help cold starting. Your car seems to be suffering from rich running when warmed up, so I'd investigate the choke's position when the choke is pushed fully IN-that is, when the choke is OFF. I appreciate it's often difficult to explain the parts one's referring to without pictures of the carb to refer to! Good luck!
Iain
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- France
I've had pretty much the same problem past week or so. Carb retuned has helped and have set of plugs and new air-filter to fit on Wednesday. So hopeful this will solve the problem completely for now. Today she was running much better following carb tinkering and we passed an F6 and a GTL on the road, both in striking orange livery, with stickers everywhere, period roof-racks etc, and their crews tooting horns and waving widely to us. Maybe it's time for the French annual youth R4 rally thing!
It is indeed that time of year/just checked 4L Magazine and then this site: same colour as the two cars we passed earlier today:
http://edition2017.4ltrophy.com/compte-a-rebours.php
It is indeed that time of year/just checked 4L Magazine and then this site: same colour as the two cars we passed earlier today:
http://edition2017.4ltrophy.com/compte-a-rebours.php
harbourseal
Renault R4 Lunatic
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I'll put in my 5 cents now.
According to all my workshop manuals adjusting the mixture is as follows.
-Warm up the engine (go for a 10 minute drive that should suffice)
-Shut down the engine and screw the mixture screw all the way in and then 3 whole turns out. (that is the basis for adjusting)
-Turn the engine back on and set the tick over at 1100 RPM (with the tick over screw)
-Now turn the mixture screw and let the engine make max RPM (until the RPM does not go any higher) Don't worry you won't break the engine because you are not working the throttle.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the the mixture screw to max RPM.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the steps until nothing happens anymore when you turn the mixture screw.
-Turn the tick over back to round 750 RPM.
Before you do any of the above make sure all the electric components are working fine and all your valve clearances are ok as Andrew says.
The above proces should give you a CO of 2-3%
I got mine back to 1,5%
This way of tuning works for both Zenith and Solex carburetors.
Best way is put your car on a 4 gas test bank and make your adjustments on that bank. But since most of us don't have one we have to do it the manual way
According to all my workshop manuals adjusting the mixture is as follows.
-Warm up the engine (go for a 10 minute drive that should suffice)
-Shut down the engine and screw the mixture screw all the way in and then 3 whole turns out. (that is the basis for adjusting)
-Turn the engine back on and set the tick over at 1100 RPM (with the tick over screw)
-Now turn the mixture screw and let the engine make max RPM (until the RPM does not go any higher) Don't worry you won't break the engine because you are not working the throttle.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the the mixture screw to max RPM.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the steps until nothing happens anymore when you turn the mixture screw.
-Turn the tick over back to round 750 RPM.
Before you do any of the above make sure all the electric components are working fine and all your valve clearances are ok as Andrew says.
The above proces should give you a CO of 2-3%
I got mine back to 1,5%
This way of tuning works for both Zenith and Solex carburetors.
Best way is put your car on a 4 gas test bank and make your adjustments on that bank. But since most of us don't have one we have to do it the manual way
harbourseal
Renault R4 Lunatic
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inwards, but at some point you'll have to do in and out as you listen to the engine or look at the RPM gage to see the it go up and stop.
You'll hopefully and up with an optimum mixture.
Maybe Mojobaby find another Zenith 28 IF and take the mixture screw out and put it in your own carburator.
There are plenty on Leboncoin after the 4L trophy has finished.
You'll hopefully and up with an optimum mixture.
Maybe Mojobaby find another Zenith 28 IF and take the mixture screw out and put it in your own carburator.
There are plenty on Leboncoin after the 4L trophy has finished.
André4Renaults
Enthusiast
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-Warm up the engine (go for a 10 minute drive that should suffice)
-Shut down the engine and screw the mixture screw all the way in and then 3 whole turns out. (that is the basis for adjusting)
-Turn the engine back on and set the tick over at 1100 RPM (with the tick over screw)
-Now turn the mixture screw and let the engine make max RPM (until the RPM does not go any higher) Don't worry you won't break the engine because you are not working the throttle.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the the mixture screw to max RPM.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the steps until nothing happens anymore when you turn the mixture screw.
-Turn the tick over back to round 750 RPM.
Yes, I agree! That's more or less what I was saying. It's important to keep fine tuning the engine until you get it "just right" and this will probably take more then one series of adjusting.
"
-Shut down the engine and screw the mixture screw all the way in and then 3 whole turns out. (that is the basis for adjusting)
-Turn the engine back on and set the tick over at 1100 RPM (with the tick over screw)
-Now turn the mixture screw and let the engine make max RPM (until the RPM does not go any higher) Don't worry you won't break the engine because you are not working the throttle.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the the mixture screw to max RPM.
-Turn the RPM back to 1100 RPM with the tick over screw
-Repeat the steps until nothing happens anymore when you turn the mixture screw.
-Turn the tick over back to round 750 RPM.
Yes, I agree! That's more or less what I was saying. It's important to keep fine tuning the engine until you get it "just right" and this will probably take more then one series of adjusting.
"
petak
Enthusiast
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Now realize that i did not put PDF file into last post.
It is attached here now.
I am very glad that you have make all this response to my zenith problem.
Will try to adjust it as Andrew and Harbourseal suggested.
Andrew....electrical part of the ignition is alright. Have checked many times in last 3 months.... spark plugs, HT leads are brand new, points are adjusted correctly, dwell angle is about 54°, timing is at +6-7°.
Only left is carb.
But need some clearing from you guys.
1. when you say "turn screw" do you mean full turn (360°) or half turn (180°)
2. How choke butterfly should be positioned when cable is fully in (choke closed)
Today have done my MOT with R4.
Pass it without any remarks. Aldo guy told me that rubber grommet on right driveshaft is about to broke and he suggested it would be wise to change it soon.
Everything is perfect according to MOT regulations (aldo they are not so rigorous)
Even my ECO TEST (exhaust fumes) are in perfect condition.
RPM's are 720
CO is 0,471% (max allowed is 3,5%)
CO2 is 14,10% (it must be between 13 and 17%)
HC is 179ppm (max allowed is 300ppm)
O2 is 1,32% (max is 2,0%)
So according to this numbers my carb is in perfect state.
But still it does "drink" to much and exhaust is black.
Would like to change that
It is attached here now.
I am very glad that you have make all this response to my zenith problem.
Will try to adjust it as Andrew and Harbourseal suggested.
Andrew....electrical part of the ignition is alright. Have checked many times in last 3 months.... spark plugs, HT leads are brand new, points are adjusted correctly, dwell angle is about 54°, timing is at +6-7°.
Only left is carb.
But need some clearing from you guys.
1. when you say "turn screw" do you mean full turn (360°) or half turn (180°)
2. How choke butterfly should be positioned when cable is fully in (choke closed)
Today have done my MOT with R4.
Pass it without any remarks. Aldo guy told me that rubber grommet on right driveshaft is about to broke and he suggested it would be wise to change it soon.
Everything is perfect according to MOT regulations (aldo they are not so rigorous)
Even my ECO TEST (exhaust fumes) are in perfect condition.
RPM's are 720
CO is 0,471% (max allowed is 3,5%)
CO2 is 14,10% (it must be between 13 and 17%)
HC is 179ppm (max allowed is 300ppm)
O2 is 1,32% (max is 2,0%)
So according to this numbers my carb is in perfect state.
But still it does "drink" to much and exhaust is black.
Would like to change that
uaz04
Due Momianesi
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My experience with our local "teknicki pregled" [before I changed to the R5 setup, of course], was that when they checked the exh gas numbers, they would play around with the carb settings until they numbers were also "perfect state". As soon as I would drive away, it would be obvious that the car runs like crap - exactly your situation...too much fuel, some black exh smoke, imperfect throttle response, etc. I'd go home and reset all by "feel" to how I like it...and all would be perfect again. It seems to me like trusting your GPS unit...turn right into a farmer's field with no road as she [always she] tells you, or trust your own judgement and sense of direction. 
mojobaby
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Hi Petak, thanks for the Zenith manual, its a great help and interesting to read! I downloaded it to my computer as well.
Many thanks Andrew and Harbourseal for your good advice and help. I have worked on my carb today but I didn't get the expected response from the mixture screw. Perhaps I will look for another carb like Harbourseal suggests. I will drive for a week and then remove my spark plugs to see their condition. Hopefully they will not be black again.
Petak, the turns are 3 full turns outwards for the mixture screw. Good news with your MOT but like uaz04 says, "you have to trust your own judgement"
Good luck with your carb!!
I downloaded it to my computer as well.Many thanks Andrew and Harbourseal for your good advice and help. I have worked on my carb today but I didn't get the expected response from the mixture screw. Perhaps I will look for another carb like Harbourseal suggests. I will drive for a week and then remove my spark plugs to see their condition. Hopefully they will not be black again.
Petak, the turns are 3 full turns outwards for the mixture screw. Good news with your MOT but like uaz04 says, "you have to trust your own judgement"
Good luck with your carb!!
malcolm
& Clementine the Cat
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Does the rpm vary at idle? If so try taking the air filter off and look down the carb while the engine is running to see if fuel is dripping onto the throttle body (it might not drip with that carb. My thought is the float valve might not be sealing).
It seems odd for a Renault 4 to run rich on a 28IF carb unless someone has messed with the jets; there is a float valve leak with dripping, or ignition has wrong timing. Good ideas from everyone above too. My F4 van is unwell with possibly a similar issue at the moment and once it becomes less dark and cold I might investigate.
It seems odd for a Renault 4 to run rich on a 28IF carb unless someone has messed with the jets; there is a float valve leak with dripping, or ignition has wrong timing. Good ideas from everyone above too. My F4 van is unwell with possibly a similar issue at the moment and once it becomes less dark and cold I might investigate.
harbourseal
Renault R4 Lunatic
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Question 1 on the basic setting you turn the mixture screw completely in and 3 full turns out 3x 360 degrees
Question 2 with the cable positioned fully in the choke is not in use so you should be able to look in to your carburetor down to the throttle butterfly
Fine numbers. Co is low
But the numbers say nothing when you are wasting fuel. 1ltr to 15 km is a minimum for a R4. If you don't reach that, adjusting the fuel consumption is necessary.
André4Renaults
Enthusiast
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The "blackness" might not be fuel related. It could be oil that is being burnt in the combustion process finding its way past the valve guides if they are worn and making the exhaust appear black. When you say the car drinks too much how much more thirsty is it than you expected it to be?
As to the choke butterfly valve, the valve should be vertical (i.e., not causing any obstruction at all) when the choke is pushed fully in (that's the choke in the "off" position)
One other thing I've JUST though of: maybe the float is damaged in the float chamber, allowing too much fuel too flow, a bit like when your ball-cock in your toilet cistern stops floating properly and allows water to run away into the toilet, except in your car it's petrol that's being flushed away! I think I read earlier in this thread that the carb body had a leak down the side of it. Maybe this is worth a look.
As to the choke butterfly valve, the valve should be vertical (i.e., not causing any obstruction at all) when the choke is pushed fully in (that's the choke in the "off" position)
One other thing I've JUST though of: maybe the float is damaged in the float chamber, allowing too much fuel too flow, a bit like when your ball-cock in your toilet cistern stops floating properly and allows water to run away into the toilet, except in your car it's petrol that's being flushed away! I think I read earlier in this thread that the carb body had a leak down the side of it. Maybe this is worth a look.