Carb setup

[F6frogie]

Hi, please can anyone tell me how I know this little shaft/diaphram part on my carb is set up correctly ?

Many thanks, Matt

 

[Steve Hennessey]

Matt, is that the 32IF carb you have there?? If so, the answers are in the Haynes manual covering the 1108 engine - the supplement is in the back of the book. Either buy the manual or ask someone to scan and email / fax the info to you. Sorry but I can't help with this one.

 

[F6frogie]

Hi Steve - Thanks anyway. Yes it is the 32IF carb that I know you recommend .
I don't have the haynes manual as yet (haven't yet got the courage to part with nearly £30 !:eek but will do soon - keep thinking a used one will pop up on eBay - if anyone could scan/send me a copy I would be very greatfull:wink:

My car seems to hesitate quite a bit when accelerating (and the odd back fire) and I am just trying to source the problem. once it has passed the hesitating stage the car is very responsive - I've done most things you would probably suggest (except the condenser which I am waiting for it to arrive) - carb overhaul, timing, points/correct gap, cap, leads, plugs/correct gap, airfilter, choke opperation, dist' vacum advance unit, fuel pump, fuel tank blockage etc etc

A little choke dosen't seem to make any differance, and I am using 95 oct petrol with a lead additive. I have only been using the car just over a week so may try the 98 oct petrol and or no additive if you think this is worth a try.

Regards, Matt

 

[Steve Hennessey]

Leaking manifold gasket??? and did you check the base of the carb including the spacer for warpage?? When overhauling the carb did you check the condition of the accelerator pump and replace if needed??
Something tells me that your problem is an air leak and/or a worn accelerator pump/valve clearances/ compressions but I'll put my money on a worn accelerator pump for now!!

 

[F6frogie]

Hi Steve, do you mean the inlet manifold or the actual carb manifold (or both)?

I presume this is the accelerator pump, and yes I thought there seemed to be too much play in the shaft (not sure if the seal (copper?)the shaft runs through would be in a rebuild kit?)- I found an overhaul kit on ebay (Item number: 350039243687) in Germany - which I have just purchased.

Is the mixture screw the one in the seperate heated manifold ? as the small O-ring on this is a little perished too.

Steve, do you know what the measurement is for the initial throttle opening ?

My Haynes manual is on its way

Many thanks, Matt

 

[Steve Hennessey]

Both Matt. The inlet manifold gasket can leak and also the carb flange can get warped so I always check for straightness when overhauling carbs. Always put a smear of Hylomar on the carb flanges and use new gaskets.

It does not matter about the play in the acc pump shaft. It the condition of the rubber on the plunger that counts.

The overhaul kit looks the right one although I would have suggested you got it from the Carburettor Exchange in Leighton Buzzard.

The mixture screw is the one in the heated manifold.

Can I suggest you wait for your Haynes Manual as there are quite a few measurements and settings to consider.

Really glad you've ordered the maunal

 

[F6frogie]

I have had the carb off today and checked the carb and heated manifold for straightness with a metal ruler - both looked fine. I have removed (again) the jets and blown through them with the compressor, re-fitted, installed new gaskets (Flexoid paper) but no hylomar as I always thought that it wasn't recommended for carbs?
I have set the mixture screw to 1.5 turns out from fully in and set the throttle intial butterfly opening to 0.8mm for the moment while I wait for the haynes manual . I have not had a run in the car yet but will tommorrow.

The accelerator pump rubber flange looked in quite good condition, it's just the shaft that has a bit of play and the mixture screw O-ring is perrished.

I have also ordered a top end gasket set so then I could have a play around with the inlet/exhaust manifold if the carb rebuild does not solve the problems.

I did contact the carburettor exchange first a few days ago but they still have not yet replied so in the meantime I kept looking and this is when I came accross the German carb parts shop on eBay.

Would you suggest I fit all the parts of the rebuild kit (Float jet etc) and still the pump if the rubber looks in good cond' ?

The parts the carb has now are -

125 0.0 - Float jet
1A - Accelerator jet
110 - Main jet
99 - Idle jet?

I have not yet checked the valve clearances.

Kind regards, Matt

 

[Steve Hennessey]

Hylomar on the base gaskets but not the float bowl - it just provides that extra 1% of insurance. Do fit all the parts from the kit then you will have eliminated everything. The mixture screw o ring is very important as it keeps the screw in the position you want it to be in. It also stops the screw coming undone and falling out (yes, I have seen this happen). The accelerator pump seal could have lost its elasticity so the only way to find out is to fit a new one.
Did you phone the Carb Exchange or email them? They never respond to fax's or emails for some reason but are very helpful over the phone - they also work odd hours.
Suggest you buy just a manifold gasket then you'll have the top end set handy for that all important overhaul in the future.
Do check your compressions and valve clearances before setting up the carb - remember, the carb is the last thing you adjust on an engine.
The jets are all the standard sizes. I had to increase the size of my main jet to prevent pinking.
There you go, I've given you more work to do!!
Steve

 

[F6frogie]

Thanks Steve for all your time and info.

I did email the Carb exchange as I thought it would be easier and the opton on their site was there. I buy most things from eBay.UK/USA as I find it a lot easier as where I live most things seem hard to get (even ordinary things) and even if I do find them, they are normally a lot more expensive in France (even with the postage).

When the kit arrives I will change all the parts and fit new gaskets and a bit of hylomar on the base gaskets as you said. I presume the mixture screw O-ring is in the kit (it looks like it rom the photo)?

In the meantime I'll check the compression and valve clearances but have never done this before (but am quite able and whould not do anything without first researching it in books/internet) - My dad will be over tommorrow who is an ex car, bike and Tank mechanic so he should be able too do these tests in a flash

Yes, I read that you increased the size of your main jet by 0.1mm !! in another post.

I was thinking of buying a compression test kit - anything to look out for when choosing (I don't want to spend a fortune) - have seen them for £10-£15 on you know where:wink.

Regarding the gearbox seals I mentioned in a previous post - I have been to Renault and they said that they were unable to get them - even from the main Renault manufacture and that they were considered as a DEAD stock!
I have found them on the Franzose site (it's a really good site) - the dimensions are 36x54x7.5 aren't they? They don't have the O-rings but if they are 104X3mm I have tracked some of these down too in Nitrile rubber in the states.

Cheers Steve

 

[Steve Hennessey]

Matt, I too once emailed the Carb exchange and waited 2 weeks for a reply before I phoned them and got an instant response!! The small o ring should be in the kit as it's an essential item.
Compression checking is easy. Buy a reasonably good compression tester. Remove spark plugs AND the power lead to the coil. Place a brick or similar on the accelerator pedal to hold it open. You'll now need the help of another person unless you're an octopus. They will need to operate the starter by the ignition switch for about ten seconds while you test each cylinder. Write down the value of each test on a piece of paper. Ie No 1 Cyl = 120psi etc. Try to get a tester in psi as old farts like me only understand imperial measures!!
If all cylinders read approx the same with no more than a 10% difference then that's good news and no need to rush and adjust the valve clearances. Concentrate your time on the carb. To test the manifold gasket, have the engine running and dribble some thin oil around the area of the gasket. If the oil gets sucked in or you see puffs of white smoke from the exhaust then that needs changing.

Regarding the oil seals and sealing rings I don't know what size they are and I'm surprised Renault have stopped doing them. When you do track the right ones down then please let us all know details of suppliers etc for the future. The sealing rings stop the gearbox oil from weeping past the threads of the bearing retainers. I do know that some years ago one could buy kits for making o rings. It was just a box full of rubber strip and super glue - if you got really stuck I'll bet someone out there makes them up.

 

[F6frogie]

Thanks again for the info Steve - compression kit bought! i'll get it tested as soon as it arrives.

regarding the DIY O ring seals - you mean like these - :wink:

http://cgi.ebay.co.uk/3mm-Nitrile-Rubber-O-Ring-Cord-70-duro-x-5mtrs_W0QQitemZ300178984708QQihZ020QQcategoryZ48718QQrdZ1QQssPageNameZWD1VQQcmdZViewItemQQ_trksidZp1638Q2em118Q2el1247

As I said I have seen the gearbox seals on www.franzose.de -

http://www.franzose.de/en/Renault/Katalog/Getriebe/ANR81092/

and the O rings I purchased from eBay -

http://stores.ebay.co.uk/BEARING-BARGAINS

Hope this helps anyone else !

 

[F6frogie]

I received the carb rebuild kit the other day which has now been fitted - it hasn't made any differance to the hesitating problem at all.

The car seems to hesitate in any gear on acceleration but not neccesarilly under much load - very frustrating at traffic lights etc as I have to dip clutch let revs rise then it hesitates until revs have increased a little and seems not bad after that stage.

There were two tiny O rings in the kit but were a little too large for the mixture screw which I thought was strange (it was a sealed kit for my exact model carb from an Italien manufacture not a home made kit) - not sure what these O rings should be for on my carb as they were non already on the carb of that size ? there was also a small alu' washer spare which wasn't on the carb before either.

I have not yet received my Haynes manual, intake gasket and compression test kit but will do more tests when they arrive - if you know of any other things I could try please let me know.

Cheers, Matt

 

[Steve Hennessey]

Matt, don't worry too much about bits being left over - sometimes they put extra bits in as sometimes kits may cover more than one variant of the same carb. The kit that I bought for my 32IF did include the right size o ring for the mixture screw and that was the one I bought from the Carb Exchange.
I can understand your frustration but wait for the Haynes manual so you can check the settings. What air filter are you using with this carb? or are you road testing without one?
One thing you can check is whether the petrol comes out of the small bent tube (the pump injector) when you operate the accelerator by hand. Is it an instant reaction or does it just dribble? Did you remove this when overhauling and blow air through it and check whether it's blocked? Did you strip the whole carb down and force compressed air through every orifice?
Steve

 

[malcolm]

Severe hesitation is normally due to the distributor. Is your vacuum advance working OK? Failing that do you have vacuum? There should be a restrictor in the pipe that connects to the inlet manifold (sorry - I remember a private message I forgot to send here). If you don't have the restrictor in the pipe then block the pipe completely.

I have a similar carb on my car and it does hesitate on sudden throttle, but I put that down to the pump in the carb not working properly. My seals are old and I haven't bought a rebuild kit yet.

 

[F6frogie]

Matt, don't worry too much about bits being left over - sometimes they put extra bits in as sometimes kits may cover more than one variant of the same carb. The kit that I bought for my 32IF did include the right size o ring for the mixture screw and that was the one I bought from the Carb Exchange.
I can understand your frustration but wait for the Haynes manual so you can check the settings. What air filter are you using with this carb? or are you road testing without one?
One thing you can check is whether the petrol comes out of the small bent tube (the pump injector) when you operate the accelerator by hand. Is it an instant reaction or does it just dribble? Did you remove this when overhauling and blow air through it and check whether it's blocked? Did you strip the whole carb down and force compressed air through every orifice?
Steve

Hi Steve, Yes I will wait for the haynes manual but I find it a little frustrating as I have sent many hours/replaced lots of part on the car over the last few months restoring it (I have included a small amount of photos in my album, not many mechanical phots though!) - and I can't get round this problem.

Regarding the air filter - I am using the metal filter box/filter assembly I presume is for this carb (the shallow type 50mm?)- again you can see this in the photos - the filter is also obviously new.

Yes, the carb has been totally dismantled, washed in petrol, and every nook and crany/jet/injector blown out using a compressor - before it was reassembled (X3 times now) and yes when the accelerator is pressed (not running), a strong sray is seen (and heard) from thr pump injector into the venturi (I have checked this several times now).

Severe hesitation is normally due to the distributor. Is your vacuum advance working OK? Failing that do you have vacuum? There should be a restrictor in the pipe that connects to the inlet manifold (sorry - I remember a private message I forgot to send here). If you don't have the restrictor in the pipe then block the pipe completely.

I have a similar carb on my car and it does hesitate on sudden throttle, but I put that down to the pump in the carb not working properly. My seals are old and I haven't bought a rebuild kit yet.

Hi Malcolm, I have sucked through the vaccum pipe linked to the distributor and can see the plate inside the distributor just move - this restrictor you speak of where exactly is it situated ?

My car also every now and then backfires, just very slightly but stops the car in it's tracks for a split second ?

Thanks for all your help guys:smile:

 

[Steve Hennessey]

Matt, this is getting even more difficult to diagnose from a distance - we will get there though. When you say backfire do you mean from the exhaust or spitting back through the carb? If the accelerator pump is working as well as you mention then the problem must lie elsewhere. I keep thinking weak mixture connected with engine gases being blown backwards through the carb due to leaking inlet valves - hence my ealier suggestion to check compressions, or the leaking manifold gasket. When the engine is ticking over does it hesitate at all? Did you squirt oil around the gasket area with the engine running?

 

[F6frogie]

Matt, this is getting even more difficult to diagnose from a distance - we will get there though. When you say backfire do you mean from the exhaust or spitting back through the carb? If the accelerator pump is working as well as you mention then the problem must lie elsewhere. I keep thinking weak mixture connected with engine gases being blown backwards through the carb due to leaking inlet valves - hence my ealier suggestion to check compressions, or the leaking manifold gasket. When the engine is ticking over does it hesitate at all? Did you squirt oil around the gasket area with the engine running?

Yes, I know it must be difficult and I am very greatful for all your help.

It backfires through the exhaust (I thought this was an ignition problem) but not all the time - lately I have been doing a 20 min journey to work twice a day and tonight it backfired once while it was actually hesitating.

When it is ticking over it is like a new car! literally, and the throttle picks up instantly even on short stabs on the pedal.

I haven't yet tried the oil around the intake gasket test yet as I was hoping to have recieved the new gasket by now and just change it anyway.

 

[malcolm]

Does sound like a weak spark. I had something very similar sounding in my MG - that turned out to be the rotor arm that had broken down and was leaking spark. It wasn't very good at lot throttle or low engine speed but was fine on full throttle. I had some coil problems on that car too, and ignition lead problems with my Renault.

PS - the hose that should have a restrictor is the one that joins to the inlet manifuld below the carburettor. I blocked mine off completely.

 

[F6frogie]

Does sound like a weak spark. I had something very similar sounding in my MG - that turned out to be the rotor arm that had broken down and was leaking spark. It wasn't very good at lot throttle or low engine speed but was fine on full throttle. I had some coil problems on that car too, and ignition lead problems with my Renault.

PS - the hose that should have a restrictor is the one that joins to the inlet manifuld below the carburettor. I blocked mine off completely.

I will check the spark on each plug but the points, rotor, cap, leads and plugs are all brand new (the old rotor was worn down pretty badly).

Regarding the inlet vaccum - should I remove the vaccum pipe there and block the end or the manifold? or both?

 

[F6frogie]

I removed the vaccum advance unit from the distributer today to check it was function properly and found to things -

one was a tiny piece of rolled paper towel inside the rubber tube which connects to the plastic pipe (mine is yellow in colour) of the carb manifold, dist' side - I presume this was to act as a restrictor but it was black with dirt so obviously after a short while it would block? Should there actually be a proper restrictor here/the other end?

I cleaned up the vaccum unit and it is working more freely now.

I then notced that the vaccum (how much it advances the timing) can be slightly adjusted inside the distibuter by means of rotating a small adjusting cog where the vaccum unit connects to the sprung contact point.

I still have not yet received my haynes manual and it has been 10 days