werber 32/36

[samsnz]

i have a holley 5200c which is a weber licensed copy of the 32/36 dfav carb. its identical in pretty much every respect.

 

i have it adapted to fit a toyota 3a-u which is 1500 opposing flow inline 4. has an aftermarket cam with slightly greater duration but it not mega lumpy and it runs/ran sweet up until recently.

 

having problems at idle with quite bad smoking, smells really rich, i have lowered my float heights, re-jetted idle and main jet curcuits far lower than it was running, replaced needle valve and seat,

 

plumbed in a fuel pressure regulator and completely stripped and replaced any wearable parts like rubber seals and washers etc. i have made the idle problem improve but i cannot seem to tune it out.

 

ive heard webers seem to like a bit of advance up to 12deg static which is maybe my next step but i was wondering if anyone had any better experience or ideas?

 

its embarrasing as and looks like im driving a diesel train down the road

[tortron]

Whats the condition of your sparkplugs?

[samsnz]

http://imgur.com/prc4PAL pic of it here, looks ok to me, they r fairly new. 2 months old perhaps, new leads also bout 2 weeks old

[tortron]

On my tablet with my dodgy eyes they look a nice dry tan which means they are running nicely and you have a pretty good mixture. At idle at least

What colour is the smoke? I assume you mean it is smoking from the exhaust rather than the engine itself smoking.

Where do you notice the fuel smell mostly? Engine bay, cabin, or exhaust?

[samsnz]

yea man its out the exhaust. when it first started it was real black but since leaning everything down a bit the smoke has lightened up considerably which makes me think towards timing issue perhaps because it even smells leaner than when the problem first arose.

 

you can only smell the exhaust in the cabin if the windows are down and the wind is blowing it past

[tortron]

For your homework i want you to drive on down the road at the usual pace. Then switch the engine off and coast to a stop. Pull the plugs and report back on their condition.

This will show up if the main jet is running rich

you want to keep the throttle open a constant amout for about a km. Dont let the car idle when you stop, turn it off before your foot comes off the throttle.

Another couple of runs would be useful too. I.e. A range from idle, 1/4, 1/2, 3/4 and wide open

if the plugs remain a nice tan colour right through, then the mixture and jetting is pretty ideal - and then you can move on to another part of the system i.e double check all fuel lines for leaks or dampness, check the carbs arnt leaking, check the fuel tank, filler tube and cap are in good condition.

Do you have a vacuum gauge?

a white or grey is lean, and sooty is rich (if theres oil on them then thats another story)

[samsnz]

plugs r about the same. no oil as far as i can tell unless its being burned off straight away.

 

ive been reading that a lot of people who run 32/36 have positive crank pressure issues and the smoking can be remedied by new piston rings. ill perform a compression test at some stage but the car goes really well besides this so i cant see how it could be +CP issues.

 

timed into 12 degress advance also and it runs much better at low speeds.