'86 AL21 3ac vacuum advance went...

[GLet71]

I find keeping my rpms's at no less than 3k gives me better fuel economy than when cruising under those numbers. dlb lent me the idea after telling me he was babying Ron everywhere, and only getting about what you're achieving. Yet, after the Tercel meet at the end of June he had to race like a bat outta hell for the ferry and ended up getting the best mileage ever!

[GLet71]

bruce, i think everyone has found that the weber does slightly stumble on hard acceleration from idle. i know that hooking up the two vacuum advance lines helped correct this on my terc, but it was never perfect. i believe it's the nature of a mismatched carb and engine. forum member glet71 now owns that terc so he might be better able to describe exactly how it runs.

also, getting the vac advance hooked up correctly will also improve the mileage. i was getting an average of 26 mpg and as soon as i got the vac advance sorted out and sold it, glet71 started getting over 30 mpg. big difference, especially on highway driving.

I find keeping my rpm's up there in excess of 3k helps keep it running smooth and clean. It seems to be lagging much more when driving around like a granny, so I recommend you give 'er. It's a win win, you get to burn around for better economy! Since buying Ron from dlb, I have done nothing with the Weber other than clean the air filter, which seems to be the must have regular maintenance schedule.

[overs10ded]

Thanks I appreciate your response GLet71! I like pushing the "lil' cupcake" around but have the frame of mind that low (rpm) and slow (mph) = fuel efficiency! (Not in airplanes though! Dangerous!) So I do lug her around, and wifee does too. It's worth a try though and I'll run next weeks fill-up using more revs as a driving technique however my little engine lugs surprisingly well with the Weber. The torque difference from the stock carb was immediately noticeable to me. However I love the throat on that pull of the secondary after 2,000rpm! Pretty sweet!
What jets are you running? My jets never arrived so I have to reorder off ebay, but I'll be in the states in 10 days so I'll bring them back in luggage, along with a laundry list of needed and spare parts.

Take care and good times!

Bruce

[GLet71]

Man, that double post was weird. I thought the first was lost in never Neverland... apparently not! As for my jet sizes, I must defer that knowledge to the previous owner, dlb, because he is the one who installed it prior to me making the purchase, sorry. Let me know how your fuel economy turns out when you get your numbers in.

[dlb]

i'm not sure about the jet sizes, they're whatever came stock with the weber.

[overs10ded]

OK, thanks guys! My Weber (oldie w/brass floats) came with 140 main jets for both primary and secondary, 60 primary idle (seems rich but 1 3/4 turns out for best idle says maybe lean?) 50 secondary idle, and a 160 air correction jet in primary, 170 in secondary. I tried switching the two airs w/each other and was worse so I want a handful of different jets to see about finding "optimum" jetting for "cupcake".

Good times!

Bruce

[dlb]

bruce, i believe that as long as the idle screw is at its 'best' setting between 1-2 turns out, the jet sizes are correct.

http://www.carburetion.com/weber/adjust.htm

[overs10ded]

Right dlb! But I have a bit of hesitation right off idle in the transition to main, the secondary is pretty bog-less with higher than 2200 rpm revs. Just would like to "fine" tune a bit to see about better drive-ability. Thanks for your response!

Good times!

Bruce

[overs10ded]

New combined mpg driving high!! 30.63 with the Weber compared very similar driving distance/route with best Aisian carb was 27.75, so almost 3mpg better with the Weber, and I think I can still re-jet a few more mpg's out of her!!! Thanks for everyone's previous experiences and posts on the forum here.

Good times!

Bruce

[overs10ded]

Best high so far is 34.5mpg w/ solid 31mpg combined!