a14gas milage

[legitimate_datto_scientist]

its an auto with only about 120k original miles on it. i get usually a mighty 22 mpg. something obviously wrong, besides the carb which probably needs to be replaced. what else can i do?

[Npdavies.]

Standard tranny would probably help.

[datzenmike]

I had a '76 B-210 with A14 motor new and only twice got the mileage below 30. Usually mid 30s and on a trip I got mid 40s on one tank. You really have to drive it hard to get below 30.

 

Short trips around town with the choke on will lower it. A stuck choke will really drop it. When warmed up take the air filter off and look at the choke plate it should be open and vertical.

[RedBanner]

40+ ftw

[legitimate_datto_scientist]

switching trannies is not an option. also, ive got my choke perma-opened

[datzenmike]

Look down carb when idling. Is there fuel dripping in? Float may be stuck/set too high and bowl overflowing.

Check timing. No idea what the correct timing is for the A. Pull and plug vacuum advance hose when setting at idle.

Check vacuum advance not leaking: remove cap and suck on hose, rotor should rotate clockwise and hold until released.

Check valve lash.

Check brake not dragging: all should spin by hand.

[RedBanner]

8-10 btdc, the best I got out of my automatic was 33-35, if you delete any emmisions equipment you can forget it,

Ive got auto rear gears, running a jetted down 1200 carb, 175/75 rear tires, and a 63a 5 speed, tuned..... Eh ok, and I get 40 on the trip to work and back, 44-6 if I keep it around 55-60, and stay off the secondaries.

[legitimate_datto_scientist]

thanks for the help. i fixed the lash and the timing, checking others. the only emissions ive got muted is the erg, i never thought it would effect my mpg, i guess ill reconnect it

[ggzilla]

120k miles is a lot. The carb is one of the first things to wear out, but not always. Make sure it is in adjustment - per the previous advice.

• A14 should get at least 35 mpg on the highway with a four speed, and up to 50 with the 5 speed.
  
• In town the A14 returns about 28 mpg.
  
• automatics get worse fuel economy.
  
• To get the optimum economy, you need stock equipment, including emission controls and stock size tires
  

[Kisor]

I'm in the same boat, 21-23mpg in my '78 B-210 auto.

 

I installed an O2 sensor and one of the Stoich meters just to see where my afr's are and it runs in the rich cruising and under wot.

 

My setup:

 

Fresh A14

Valves adjusted recently - 20-22in vacuum at idle

Hitachi carb, 106 jet primary 145 secondary (anyone have a 95-100?)

18* base timing, 10 has no power, have been progressivly going up, going to check tdc for accuracy

No egr provisions on manifolds or cyl head ??

No A.I.R. or catalyst, air pump was locked up, stolen cat :(

24.1" tall tires, speedo 5% slow. verified via gps

Automatic trans and stock rear, haven't verified ratio

 

So what am I missing? lol..

 

I drive hard, 75mph highway 60%, easy side streets 40mph. I know thats prob where most of it is but its not 10mpg that everyone else seems to get from theirs.

 

I could drive the shit out of my '97 Integra with more displacement, 50more hp and prob 1000lbs over my B and still get over 30mpg.. What gives???

[ggzilla]

Under wide-open-throttle it should be running rich. Even the new cars do this. But at cruise is should be just at 14.7:1 (which is why the emission controls matter, because MPG is better at leaner than 14.7:1).

 

Missing EGR and smog pump will have no detrimental effect on fuel economy.

 

18* base timing is wrong, it will be too advance at high RPM. Make sure you check the timing at idle with the vacuum advance line disconnected and plugged. Put it at 7 for stock, although 10 is OK. If you get "no power" then something is wrong!

 

* speedo 5% slow -- so consider that in your MPG calculations

 

* 75mph highway 60%, easy side streets 40mph -- that's your problem. A14 with Auto at 55mph it will return over 30mph, but drops the faster you go

 

* my '97 Integra with more displacement, 50more hp and prob 1000lbs over my B and still get over 30mpg. -- The Acura has better gearing. If you put a 5-speed overdrive, your A14 will get MUCH better mpg, about 10-15 mpg better -- the effect is exponential. A 4-speed automatic will also up the MPG. Lowering the RPM at cruise will increase the fuel economy fast. Likewise driving 10 mph faster will have an exponential decrease in fuel economy. The Acura has better aero and better gearing. And a computer-controlled fuel system. The B210 cannot compete with that.

[Kisor]

Under wide-open-throttle it should be running rich. Even the new cars do this. But at cruise is should be just at 14.7:1 (which is why the emission controls matter, because MPG is better at leaner than 14.7:1).

 

Missing EGR and smog pump will have no detrimental effect on fuel economy.

 

18* base timing is wrong, it will be too advance at high RPM. Make sure you check the timing at idle with the vacuum advance line disconnected and plugged. Put it at 7 for stock, although 10 is OK. If you get "no power" then something is wrong!

 

* speedo 5% slow -- so consider that in your MPG calculations

 

* 75mph highway 60%, easy side streets 40mph -- that's your problem. A14 with Auto at 55mph it will return over 30mph, but drops the faster you go

 

* my '97 Integra with more displacement, 50more hp and prob 1000lbs over my B and still get over 30mpg. -- The Acura has better gearing. If you put a 5-speed overdrive, your A14 will get MUCH better mpg, about 10-15 mpg better -- the effect is exponential. A 4-speed automatic will also up the MPG. Lowering the RPM at cruise will increase the fuel economy fast. Likewise driving 10 mph faster will have an exponential decrease in fuel economy. The Acura has better aero and better gearing. And a computer-controlled fuel system. The B210 cannot compete with that.

 

 

Thanks Zilla, maybe I came off sounding a little less informed than I am in that last post. lol...

 

I know where my afr's should be, Hence why I asked if anyone had any smaller jets. My secondary jet I think will be fine if I can get the primary down a bit.

 

I don't know why, where, or how my engine had the EGR removed. There isn't any ports machined into the head or manifold. Just blank spots in the castings. Makes me wonder what year make and model they are from.

 

The timing at 18* is where I'm at with small increases of a couple degrees over the past couple weeks. Again my next step is to verify my TDC and timing mark to see if I have balancer slippage or something else going on.

 

I understand slower cruise speeds will net better overall mileage but I would rather not get ran over than net a few MPG's. haha

I can't imagine its worth 10mpg... maybe I guess...

 

That sucks the B was rated at 30 some mpg with the auto and just a couple driving changes kills 10mpg. Using the Integra may have been a bad example but I could beat the crap out of that car and It would cost maybe a couple mpg's.. not 10+

 

 

 

 

I'll officially ask here and idk if a seperate parts wanted thread is needed but if anyone has any Hitachi jets in the 90-100 range let me know. The narrow band guage I'm using isn't the most accurate way of tuning my car but it gives me some clue as to where my mixture is and needs to be. I may try to grab a wideband locally and see how far i'm off.

 

Thanks,

Brad

[legitimate_datto_scientist]

funny, my speedo is abou 5% slow also. and my odometer has stopped making accurate calculations difficult. but i know its not where it should be. i adjust the timing and lash it seems slightly better. ive noticed my mpgs are much worse in heavy traffic when im idling alot. much worse

[ggzilla]

Adjust the idle mixture screw. When set to the correct best-lean procedure, the idle fuel economy will be similar to newer engines.

[Master-O-Turbonics]

I think the worst city mpg I got was 28mpg averaged on a whole tank.

35mpg on combined hwy/city.

This was with a 5spd.

Never burned out a whole tank on highway with it.

 

3.90 gear, 185/65 R14 tires

[ggzilla]

Yeah with a 4-speed or 5-speed you can get 28 city.

 

But not with an automatic.