poor cold starting+ idle jet circuit

[srtames]

My 1.4 with 32dir carb is very poor at starting in this very cold weather. I have to crank the engine for about 2 minutes. I have had new rotor, dizzy cap, leads, plugs and the spark plugs are the right colour. I have cleaned the idle jet but am loath to strip the carb top but may have to. Is this due to not having a proper fuel enrichment choke as the idle jet is so tiny to drag fuel through. Perhaps there is a blockage further in. Would be grateful for a diagram showing the idle passage ways.

Thanks, Steve

[volvodspec]

no need to, i have a seetrough of the carb but never got it to the point where i thougt those drawings could be usefull.., the 32 dir carb is way too simple to make it that hard for yourself.

first a few simple things,.

the idle jet makes the car run stationary on its own by squirting a small amount of mixture into the inlet manifold.

choke makes the mixture richer by blocking some of the air and making sure that some extra fuell is going to the inlet manifold via a leaver that puts the gaspedal mechanism a bit open..

when the idle jet is the problem, it should still start on choke, but won't run stationary unless you press a little on the gaspedal.


seen the fact that you've already changed the ignition the cause will definatly be in the fuel region.

first, dismount the airfilterhousing

you can test the idle jet by turning ignition on, and then take the connector with the blue/red wire of the idle jet and then tap it on the connector, you should hear a clicking noise. meaning the electrics is ok.

if you have an air compressor you can use it to blow trough the carb channels, simply remove the idle jet (wrench 13) and blow a little, be carefull cause the petrol will exit out of the carb up into the air! there are a few other likewise channels that you can blow clean as above, see below.

next check the fuell pump, remove the the leading spark-plug cable, disconnect the fuell line from the carb and put the end of it in a bottle, crank the engine and instantly there should be a good amount of petrol coming into the bottle. you can also check the bolts of the fuellpump cover, 6 small ones and 2 big ones.

check if the 5 screws of the carburator lid are firmly tight, don't put the screws too tight, its only m5 thread and aluminium.. when the screws are loose this would probably help a lot, the 4 nuts at the bottom of the carb tend to get loose aswell, this will make air get into the inlet manifold that will fuck up the burning process.

next, look at the top of the carburatur and now manually move the throttle lever, there should be a nice amount of petrol injected into the carb, and there should be a stream well visible. if not, remove the carburator lid, blow trough the 2 fuell jets at the bottom of the petrol storing cup, blow trough the air jets on top of the carb and make sure that the jet just aside of the 2 air jets is tight and with the "sprayer nozzle" into the chamber that is on the side of the valve cover.

pick up the carburator lid and dismount the floater, put it in a cup of water and push it under water, make sure that the floater isn't leaking or getting water inside of it. build the floater back to the carb lid and hold the lid upside down, now adjust the heigt of the floater with the gasket thickness in mind to 7mm by bending the floater mounting

build the thing back together and replace the carburator lid gasket by a new original one (never use liquid gasket on these carburators!! saves you a lot of trouble!!)

try starting the engine and reving/adjusting. most likely the car will be more fuell economic and definatly a lot more reliable;) and if you have recently adjusted stationairy and co the car will initially runn terrible;)

[srtames]

Thanks for the info, I blew through the emulsion jet and main jet and seem to make a big difference. There were also two very small jets which I dont know their function. I notice that the breather pipe from the rocker lets through unfiltered air and wonder if oil droplets were the blockage cause? Its a fiddle getting the linkakages back .

Regards, Steve

[Chris_C]

I notice that the breather pipe from the rocker lets through unfiltered air and wonder if oil droplets were the blockage cause?

It was on mine.... my crankcase now vents to atmosphere and it doesn't happen anymore.

[srtames]

I downloaded the info from the tech page and there was a very good diagram of the webers action. The very small jet appears to be a second idle air jet which if blocked may explain why you need more throttle to keep the engine idling. I think I willtry to fit an oiltrap on the breather . If you lleave the breather off you may get mayonaise in the rocker and will the mot man object!

regards, Steve