Technical Carb problems - running too rich

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Technical Carb problems - running too rich

Why don't you stop pissing about and take it to a garage who know what they are on about? Seems like sometimes people enjoy having problems without a clue about solving them. Take your car to DTR in south coulsden,surrey and they will have it running like a swiss watch. IF YOU DONT KNOW WHAT YOURE DOING< DONT DO IT!!! spend a few quid and stop stressing about it.
 
Update:

Have now discovered that my fuel cut-off valve isnt working - this should cut the engine immediately if disconnected, right?
You mean the solenoid thingie at the base of the carb? Yes, it should kill the motor at once by cutting off the idle circuit, but nothing awful will happen if it's not working. The motor might run on for a moment after you shut it off, and restarting might be a bit more difficult, but it won't affect running at all. I'd not worry about this until you have everything else running right, especially because....

Also, I have read that to set the idle/mixture correctly you need to warm the engine up and then prop the choke wide open. However with the choke completely open I cannot get the engine to idle at all, no matter what position the idle screw and mixture screw are in. I guess it's lucky that the autochoke only half works.

Now, that is interesting, and suggests that you have a respectable vacuum leak somewhere. Air is getting in where it shouldn't, so to get a decent mixture, you have to cut down on the air coming in where it's supposed to. Likely you're also idling on the transition or main circuit, and that would explain why the idle stop solenoid isn't working - it doesn't affect those circuits. If you do have a vacuum leak, you'll have to find it and fix it first - it is impossible to tune a carb that isn't seeing all the air that's coming through.

Oh, and float level too high and main too rich are the sort of adjustments people make when they have a vacuum leak and don't know it.:bang:

I'm going to rebuild the carb over the weekend (including a new float and needle valve). One more thing: there is a connection on the left of the carb (under the fuel pipes) which is not connected to anything(although it was covered witha rubber bung). If I remove the bung and put my finger on the hole with the engine running there is quite a strong vacuum, I guess this is for cars with vacuum advance on the distributor - should it be connected to anything on my car?

Make sure the rubber plug is good and not leaking vacuum... And then leave it blocked until you have everything else working. Your first order of business is to get to where the car idles properly, and then you can build from there.
 
For clarification, and to clear up confusion - the european specification carbs do *not* have a cut-off solenoid, it is pretty much unique to the federal spec cars.

I agree about the air leak. Without adjustment the car would run lean (if it runs at all) so it tends to need additional, sometimes unnecessary, fuelling.

The most likely candidate is the splash/catch tray under the carb - these can crack as they get old. After that you just have to check all the gaskets.

I had a huge problem on my last X1/9 with the exhaust manifold - it was not a standard manifold and had been fabricated too thick so the inlet manifold was not properly clamped at the bottom where it shared a bolt/stud with the exhaust. It all looked fine but ran like a dog... 5 minutes with a dremel and it was all sorted!
 
Why don't you stop pissing about and take it to a garage who know what they are on about? Seems like sometimes people enjoy having problems without a clue about solving them. Take your car to DTR in south coulsden,surrey and they will have it running like a swiss watch. IF YOU DONT KNOW WHAT YOURE DOING< DONT DO IT!!! spend a few quid and stop stressing about it.

The whole reason I am asking questions on this forum is that I want to fix the problem myself - surely that is the whole point of forums like this - people share knowledge and help each other out. Having just spent £1k on buying the car and then shelling out for tax and insurance I am in no position to take it to a garage who may charge me another £200 to get it running right - I was hoping that there would be a simple reason why the car is not running right that I could fix myself. I would add that I have a lot of experience with mending cars (if not i probably wouldnt be driving old Fiats), but I have only had experience of SU and Solex carburettors before, so the weber is something new to me.

To everybody who has been offering advice, it is greatly appreciated, and hopefully I will be able to return the favour soon enough!

Cheers,
Jim
 
Hi Jim, totally agree with you, as I have said repeatedly, I don't own the knowledge, I am only the custodian of it, If I can help on this forum I do, that is the whole point of it afterall, I have said before that some people here tempt us with info but then don't follow through, maybe not so much in the X1/9 forum but certainly in the Ulysse section. Sorry rant now over!!!, stuck here in Greece and no fuel, tanker drivers strike today:cry:
 
hah - learn something new every day

For clarification, and to clear up confusion - the european specification carbs do *not* have a cut-off solenoid, it is pretty much unique to the federal spec cars.

OK, makes sense (or as much sense as any of the US/Euro differences do:p). Thanks, and I will try to remember this when offering tuning advice across an ocean.
 
I think that people seem to have hit the nail on the head. You have a leak on the inlet somewhere letting in air. If it was me i'd start at the top. Rebuild carb (its nearly 30 years old with rubber bits) while the carb is off check the carb heat shield for crack (as per jimbro) change all the gaskets when you put it back together. If that doesn't work take the inlet manifold off and check the manifold gaskets and as jimbro (aka the oracle) says check the depths are the same on the inlet and exhaust manifold. While the inlet manifold is off give it a right good clean and check for cracks. Remember these were cast by hot and bothered italians (that'll do francesco, they're only going to England...)
 
A quick check

One quick check for a vacuum leak.... Try spraying ether or carb cleaner on any suspect area. If the engine speed changes, that area is definitely leaking.
 
I think that people seem to have hit the nail on the head. You have a leak on the inlet somewhere letting in air. If it was me i'd start at the top. Rebuild carb (its nearly 30 years old with rubber bits) while the carb is off check the carb heat shield for crack (as per jimbro) change all the gaskets when you put it back together. If that doesn't work take the inlet manifold off and check the manifold gaskets and as jimbro (aka the oracle) says check the depths are the same on the inlet and exhaust manifold. While the inlet manifold is off give it a right good clean and check for cracks. Remember these were cast by hot and bothered italians (that'll do francesco, they're only going to England...)

It's better than that - the carb's themselves are reputedly cast from what is referred to as "monkey metal" in the trade, recycled aluminium alloy with wildly varying levels of purity, the result is that different parts can behave differently when heated up, not much different from the ally cylinder head on a steel block. This gets worse over time too.
 
Haven't had chance to check mine yet, but I've seen a few X19 inlet manifolds on ebay with a pipe coming off the left hand side. What would this be connecting to? There's no brake servo, and no vacuum advance on the distributor, so I'm a little puzzled (again).
 
Have just ordered a rebuild kit from Eurosport - includes everything except for the choke diaphragm, and was slighlty cheaper than FastRoadCars. If this doesnt help then I am going to have to get it to a garage I think and leave it to the professionals!


Did you fit the carb rebuild kit from Eurosport after, and has it had any effect on the running? :)
 
turbo jim-apologies for my rudeness..didnt appreciate you werent in the position to take your car to a garage. I bought a weber service kit and had DTR strip and rebuild my carb-They did a great job and doesnt take too long/cost too much. Sometimes its better to pay for an hours labour and get it sorted-thats what I was getting at. Good luck..Lucio
 
Re. the mystery pipe, I've discovered that that it's a water pipe for the carb, rather than a vacuum pipe. Didnt realise the manifold had a water jacket!

Martygf- havent yet got round to using the rebuild kit, I've been too busy to spend much time on the car unfortunately. Will let you know how I get on.

Lucio - I would love to take the car to somewhere like DTR, and if I knew it would only be an hour's labour then that would be fine. My worry is if the garage I take it to needs to spend 3 or 4 hours on it then it's going to cost mega-bucks. At the moment I'm beginning to feel that it's going to have to go to a garage though. Hopefully the rebuild kit will help in some way, and I'm also going to clean the inlet manifold and heatshield, then reassemble with new gaskets.
 
You could always take it to DTR and have them take a *look* at what the problem is and then quote you for how long it will take to sort. I have used them for years and cant recommend them enough-honest and reliable and more importantly they know their Italian cars-talk to Paul-he even *had* an X/19.
 
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