Good day to all. M new B from malaysia and using a 1985 Mazda 323 sedan. I'm a bit DIY so would like to know how to tune this carburetored vehicle. Without dismanteling the carb, I can see 3 external screws; 1 for the air-conditioner's idling, 1 for the engine's idling but not sure what the 3rd is for. 3rd screw is screwed into the body. I suspect is for fuel/air mix.

Current problem: High fuel consumption at low speeds (I'm stuck in traffic everyday), almost 1/4 tank of fuel round trip of 25kms.

Question: 1)How do I reduce the low speed fuel consumption? (besides leaving the car at home, public transport here seems to serve the transport companies rather than the public). 2) Does screwing in 3rd screwincrease fuel or reduce fuelin the fuel/air mix?

Apologies if this have been asked elsewhere in the forum. Just point me in the right direction n I'll try out your suggestions.

thanks & regards,
kevinlw
Kuala Lumpur Malaysia

 

It is for idle fuel mixture. Hard to say if it will cure your problem but worth a try. One common problem i have seen on those is the spray pump bore wears out. This requires replacement of the carb basicly. You probably have fuel leaking by your spray pump seal. You will have to take the top off to replace/inspect it. You may get lucky and only need a spray pump.

 

thanks for the info hixx. My mechanic gave the carb a wash and retuned it, economy seems to have balanced out i.e. as long as me wheels are correctly inflated, no noticeable fuel guzzling activities seen.

However, now a diffrerent animal has reared its head, knocking! happens regularly in 1st gear and below 2500rpm in 2nd, progressively reducing as I go up the gears. My mech had tuned the mixture to a level where there's condensation on rainy days or cool days with relatively high humidity. in Malaysia, humidity never drops below 50% even in the high mountains!

Regular driving on level roads seems ok until I try to accelerate hard, then the knocking come back during the hard acceleration. knocking also happens going up gentle slopes in 1st & 2nd gears.

Maybe its' high time I change cars? But due the current value of the old fella, I have to mortage my house (which I don't own) to finance a pre-owned car of younger age. 8-P

Wonder if there's hope for me car.

regards..

 

Anyone out there have a manual for my model's carb?

kevinlw

 

Hi Hixx,

Adjusted the idle mixture and managed to get my consumption down to a manageable level. Still bad compared to pre-servicing. before I used to get about 300kms for 26liters of petrol. Now I'd be lucky to get 250kms for the same amount.

I'd found my vacuum advance hose a little stiff, could this be the cause of the knocking? And how do I remove the distributor arm for replacement & adjustment?

regards,