Another little problem,hunting at idle?

[robbocop]

I've just rebuilt the carburettor on my Le car turbo,in the short time the cars been running it's hunting at idle,the revs are going up and down quite a bit,it's ok with the choke on though?It did actually snap out of it for about 2 minutes,i managed to get it to idle very very low and it just wouldn't stall.Turned the car off,came back later and fired it up and it started hunting again?The air mixture screw is 1 and three quarter turns out,is this about right?

 

[phildini]

Most of the time it's an air leak

 

[sparkie]

which gaskets did you actually end up changing?

did you clean/soak the carb with petrol before re-assembly?

i rebuilt mine last week, and it seems ok. - although i did have to make a few new gaskets out of 'notepad backing cardboard' - the ones where the carb mounts on the 'plenum' and the gaskets either side of the plastic spacer plate.

 

[kruxing]

Try the card board packing or make a gasket out of corksheet.If that doesnot work check the butterfly valvle they tend to worn out with time.

 

[robbocop]

It was a genuine Weber rebuild kit i used,had everything in it!Cost me about £80 a year ago.It was strange that for a period of about 5 minutes it cleared itself,i switched it off then,went back later to start it and the idling was irratic again?.

 

[sparkie]

hmmm, i bought a 'genuine weber kit' too but cost me £35.
maybe there were two types? - basic kit and a extensive rebuild kit?

what i did find was that if i looked down the first stage, the secondary venturi was dribbling fuel on idle, that caused the car revs to go all over the place. - i changed the float chamber jet back to the original one and tightened the top of the carb down *really tight* and it seemed to stop doing it. - look down the 1st stage with a torch and see if its spitting/dribbling fuel.

 

[robbocop]

My kit had the thick plastic base gasket included,all other gaskets,all jets,diaphrams etcOnly pain was the mixture screw was different which i really wanted to replace,the rubber o-ring/seal on it was too thick and it wouldn't go down into its hole,i just had to use the original one.

 

[gtturbogordini]

Mine was doing that for ages, the plugs start to get black and it's then hunting, I've since been able to do some long distance miles and found iv'e had to change the mixture a few times to get it right. but now it's settled down and i've found i've had to richen up the mixture slightly after first weakening it. I've played around withy it for a while and while not perfect it happily idles fine now.

I've got an exhaust with chrome pipe at the back and you can tell by the tone of the build up on the inner tip if it's too rich. ie very black, but it';s now more of a grey colour which seems much better.

 

[robbocop]

hmmm, i bought a 'genuine weber kit' too but cost me £35.
maybe there were two types? - basic kit and a extensive rebuild kit?

what i did find was that if i looked down the first stage, the secondary venturi was dribbling fuel on idle, that caused the car revs to go all over the place. - i changed the float chamber jet back to the original one and tightened the top of the carb down *really tight* and it seemed to stop doing it. - look down the 1st stage with a torch and see if its spitting/dribbling fuel.

I've just taken the ducting off the carb and it's doing exactly what you're saying,dribbling fuel in the secondary venturi,isn't that odd both having the same problem after a rebuild?I'll change it back to the original one(which ofcourse im looking frantically for and can't find)and i'll see how i get on.

 

[robbocop]

I've rep[laced the float needle jet and the two jets at the bottom of the bowl with the original ones and the fuel is still spitting and dribbling down from the venturi?Car is ok with the choke on,just when you get to the point the choke is about off the car starts revving up and down and wants to stall,and eventually will stall.

 

[sparkie]

have you tightened up the float chamber jet enough, to nip up on the aluminium washer?

i noticed when you looked down from above at the two air correctors, there is a small circle slightly off to one side that shows the gasket, and as the car runs, it got wet. but when i tightened up the screws on the top of the carb. (i had to really tighten it loads) it stopped leaking.

 

[robbocop]

I take it by float chamber jet that's the float needle valve jet under the float pin?Might be onto something there as i can't remember there being a washer/gasket under that when i renewed it!but there was a aluminium washer in the new kit!I'll stick it on tomorrow and see if its any better.Thanks!

 

[sparkie]

yeah, its the one under the float pin. - there was definately an aluminium washer on mine. - make sure you havent got one on, and its stuck itself to the carb top - i had to use a screwdriver to tap my original one off.

 

[robbocop]

Made a bit of progress today.Car starts every time now and idles for ages quite smoothly.Just very rarely for a couple of seconds this really acrid,choking smell gets in the air and the fumes go a little blacker,but it always disappears?All i did was strip the carb down again and clean everything,changed the seal on the mixture screw,changed the shorter mesh filter at the fuel inlet back to the original longer one and something seems to have worked!The washer 'was' on the float needle valve base,couldn't remember it being there!

 

[robbocop]

Can't believe this.Car has started and idled fine for the last two or three days.Late yesterday however the choke just suddenly decided when you pull it out it wasn't going to have any effect on the carburettor whatsoever??With a bit of coaxing it run.Now today a bigger surprise,it won't start at all!!!!!Not even thinking about it,it just turns over all the time,i think my patience has just run out.

 

[sparkie]

flooded or no spark?

check the spark first.

then get a can of deodorant, or carb cleaner and spray directly into the carb. - it will force the car to start.

 

[robbocop]

It's not getting a spark.Although saying that i only come to this conclusion after trying one lead and plug lying against the cylinder head to look for a spark,there wasn't one.But then i thought for the hell of it i would test all the leads with the spark plug stuck in them lying against the engine,only two of the leads gave a spark??and this didn't mean two of the leads were faulty either as i swapped the leads over to the cylinder i was getting a spark and it was fine!So this meant two of the leads weren't getting a spark from the top of the cap?Im renewing the cap,leads and rotor arm.

 

[mrdini]

It's not getting a spark.Although saying that i only come to this conclusion after trying one lead and plug lying against the cylinder head to look for a spark,there wasn't one.But then i thought for the hell of it i would test all the leads with the spark plug stuck in them lying against the engine,only two of the leads gave a spark??and this didn't mean two of the leads were faulty either as i swapped the leads over to the cylinder i was getting a spark and it was fine!So this meant two of the leads weren't getting a spark from the top of the cap?Im renewing the cap,leads and rotor arm.

try to avoid the nasty red plastic cheap variety that a lot of motor factors sell i have had bad experince of those, i now have the black ducelier type and thats fine

 

[robbocop]

It's not getting a spark.Although saying that i only come to this conclusion after trying one lead and plug lying against the cylinder head to look for a spark,there wasn't one.But then i thought for the hell of it i would test all the leads with the spark plug stuck in them lying against the engine,only two of the leads gave a spark??and this didn't mean two of the leads were faulty either as i swapped the leads over to the cylinder i was getting a spark and it was fine!So this meant two of the leads weren't getting a spark from the top of the cap?Im renewing the cap,leads and rotor arm.

try to avoid the nasty red plastic cheap variety that a lot of motor factors sell i have had bad experince of those, i now have the black ducelier type and thats fine

That'll be the nasty cheap plastic red one i've just gone and bought then! :lol: To replace the nasty cheap plastic red one that was already on it! :roll: I'll look into trying to find a good one.

 

[5atmo]

Where do you get them from? I have been looking everywhere and even Renault say that they are no longer available for the atmo.