whats up with the bad mileage?

[Yo'J]

I want to jump into this...I have a weber dgev on my 82 wagon and I can't seem to get better than 20mpg. Its almost to 220,000, and the compression isn't that good. I've replaced everything, 5speed d/r tranny, front axels, rear bearings, manifold from a 85', coil, disty, filters, new holly fuel regulator, inline pressure gauge running at 2.75lbs, plugs, o2 sensor, wires, hoses, alt, starter, radiator and yesterday, starter switch, my primary and secondary jets are 140 and I feel bad about the mileage. No leaks found unless its in the dash on the heater stuff. I haven't completed the search there but I don't hear anything and the temp maintains itself perfectly.

 

I have slight hesitation when cold and not that much power till its warm and then only around 3000rpm.

 

What should I have for jets and what should the timing be? It doesn't change for webers right? Its at 8btdc now. The float is adjusted to factory and I don't understand the variations in float leveling. The float was way off from factory, I got the kit for my deceased ea82. (I wasn't going to put on a third set of heads)

 

I pulled the egr system and blocked off the hole. All the stuff had busted hose bibs and I was recommended to do so (from some site before I found all you). pcv stuff is all there. I do now have a full extra set of manifolds though for different years.

 

Mostly I assume my motor is old and almost shot. But if I'm missing something I want to know.

 

I would love to figure out this motor before I do myself an ej swap and lift. I feel like I wouldn't have learned a thing.

[GeneralDisorder]

.... o2 sensor....

 

Why would you replace that if you have a Weber?

 

Tire inflation?

 

I would be checking the float level, and your air bleed's and idle jets as well as your mains.

 

You very well may have to rejet - engine's aren't all the same and if the volumentric effeciency of your engine is lower than the carb is jetted for you will have to rejet and retune.

 

GD

[Yo'J]

O.K.the air is 170 and 160, the idle is 60 and 50. The o2sensor I had extra, the old one looked like a ball of moss.

[GeneralDisorder]

O.K.the air is 170 and 160' date=' the idle is 60 and 50. The o2sensor I had extra, the old one looked like a ball of moss.[/quote']

 

Those are baseline jets for the EA's, so that looks fine.

 

O2 doesn't do anything with a Weber. Might as well have put a spark plug in the hole.

 

How's your choke set?

 

GD

[Yo'J]

For a little bit of history. When I picked up the car it wouldn't idle at all, but its a subie. 15 min and the plugged crap came off and I drove it home, swapped the weber. At first it melted plugs and the disty rattled like a spray can. It drove with a black cloud behind it and got 10mpg due to old lines and a manifold leak. New gaskets and hoses, now, 20, is way better but not good enough. The old owner didn't know what he was doing and rewired over shorts and killed the interior like a slob. The uhaul toe hitch its got was wired loose over the muffler and was attached with coat hanger wire, rusty, coat hanger wire. Oil was everywhere, the rear seatbelts were a sponge and the seats came out as soon as it was home. Its a two seater now with a lumber rack. Runs and starts fine with no shorts but it has been a long haul.

[idosubaru]

O2 doesn't do anything with a Weber. Might as well have put a spark plug in the hole

AWESOME!!!!!!! with ignition cable PLEASE!!

 

what kind of mileage should he expect?

 

what kind of driving are you doing. if you're doing heavy footed stop and go driving in town and short trips all the time you're probably getting about right.

 

check your brakes. even on cars without any brake issues (mine) i've seen mileage go up 3mpg after a brake job. make sure caliper slides are no only greased but greased with brake caliper lube only - not just any old grease.

[idosubaru]

you posted while i was posting...sounds like a work in progress. have you had it long enough to run through a full tank of gas?

 

is the motor noisy at all - like valves tapping?

 

sounds like maybe it sat for awhile, definitely check things out on the motor and i'd check brakes.

[Yo'J]

Those are baseline jets for the EA's, so that looks fine.

 

O2 doesn't do anything with a Weber. Might as well have put a spark plug in the hole.

 

How's your choke set?

 

GD

Well seems fine. Just adjusted it a month ago to be sure. Sparkplug? Would it fit? That would look cool, not something to wire though...jskddn! Better than wasting a good 02 sensor.

[GeneralDisorder]

AWESOME!!!!!!! with ignition cable PLEASE!!

 

I just mentioned that because it just so happens that they share the same thread size and pitch . I actually have used them to bock uneeded O2 bungs. Not pretty, but they certainly do the job and aren't dangerous or anything. They are designed to hold back cylinder head temps and pressures after all.....

 

what kind of mileage should he expect?

 

That depends on a lot of factors, but for reference my Brat routinely got 27 with a baseline jetted Weber DGV, as well as my '86 EA82 sedan. My 84 wagon, when it was 2WD, once got nearly 32 on a long freeway run of about 400 miles. All three were running Weber DGV's - one new one, and one I rebuilt myself. Same baseline jetting.

 

However.... if you have a "lumber rack", you will severely cut into your mileage. I would expect to see around a 2 to 3 MPG loss just with a big ol' rack on top like that.

 

Now - my 84 wagon, once converted to 4WD ('82 4 speed), lifted 5 inches, and sporting 28" mud tires (but no rack on top), took a huge hit in mileage. On long freeway trips I would average just over 20 MPG.

 

what kind of driving are you doing. if you're doing heavy footed stop and go driving in town and short trips all the time you're probably getting about right.

 

I wouldn't think quite so much. The lumber rack will cut into the freeway mileage, but doesn't affect it much around town at slower speeds. I would guess 24 or 25 MPG should be seen with mostly in-town driving only. But probably not much more on the freeway when the rack comes into play.

 

All-in-all, I think you aren't far off from figureing it out. If the engine efficiency is down a bit, a little rejetting and tuneing with some choke adjustments should get you back up to around 25 at least I would think.

 

GD

[Yo'J]

Hmmm I got the brakes inspected when I got it. I'll check again. I put new calipers on the back... whatever they are called for drums, the "actuator". Tires are good. The hill holder is bad and needs to be replaced or fixed, I have a replacement already....If its bad, like, not working, it wouldn't stay on, would it?

[Yo'J]

However.... if you have a "lumber rack", you will severely cut into your mileage. I would expect to see around a 2 to 3 MPG loss just with a big ol' rack on top like that.

 

Now - my 84 wagon, once converted to 4WD ('82 4 speed), lifted 5 inches, and sporting 28" mud tires (but no rack on top), took a huge hit in mileage. On long freeway trips I would average just over 20 MPG.

 

 

 

I wouldn't think quite so much. The lumber rack will cut into the freeway mileage, but doesn't affect it much around town at slower speeds. I would guess 24 or 25 MPG should be seen with mostly in-town driving only. But probably not much more on the freeway when the rack comes into play.

 

All-in-all, I think you aren't far off from figureing it out. If the engine efficiency is down a bit, a little rejetting and tuneing with some choke adjustments should get you back up to around 25 at least I would think.

 

GD

 

 

O.K. the rack is pretty slimline, I did o.k. work. its cedar and light weight. I don't drive like a grandpa but I try to keep it under 4000 rpm. Most of the time I'm driving in town with lots of stops and short runs. Working in town here is a driving pit of hell. I'll do wheel lube and check the brakes out.

 

As far as a rejet goes, its clean in there. What should I jet too, or should I just clean them anyway. Whats good settings for the float, economy and/or offroad?

[GeneralDisorder]

As far as a rejet goes' date=' its clean in there. What should I jet too, or should I just clean them anyway. Whats good settings for the float, economy and/or offroad?[/quote']

 

You can get a jetting "kit" from Redline. That might be the way to go.

 

Here's a thought - for a small investment, you can take advantage of that new O2 sensor you installed - there's several availible narrowband monitors out there for cheap. You can then make a much more qaulified and informed judgement on your jetting choices.

 

Here's a decent autometer setup for about $60:

 

http://search.ebay.com/search/search.dll?sofocus=bs&sbrftog=1&dfsp=32&catref=C6&from=R40&mppfqy=air+fuel+ratio&satitle=air+fuel+ratio+3375&sacat=-1%26catref%3DC6&fmmk=&fmmd=&fylo=&fyhi=&mppfqy=air+fuel+ratio&sargn=-1%26saslc%3D2&sadis=200&fpos=97068&sabfmts=1&saobfmts=insif&ftrt=1&ftrv=1&saprclo=&saprchi=&fsop=32%26fsoo%3D2&fgtp=

 

And here's a cheapy for $32:

 

http://cgi.ebay.com/ebaymotors/PERFORMANCE-FUEL-AIR-RATIO-2-GAUGE-52mm-METER-Mirror_W0QQcmdZViewItemQQcategoryZ46100QQihZ018QQitemZ280237028507QQrdZ1QQsspagenameZWDVW

 

I just did a search for "air fuel ratio" on ebay. There's a lot of options, from cheap monitors like I sugested, to wideband monitors with special sensors - I have an NGK wideband for my 91 SS project, but the wideband stuff isn't cheap - around $260 for mine.

 

GD

[Yo'J]

Now that is the way to find good jetting! I'll get one of those!

[GeneralDisorder]

If you are going to shoot for leaning it out for best mileage you will also probably want to monitor exhaust gas temps. They will increase as you lean it out - can burn valve seats and stuff if you go too far.

 

GD

[mountaingoatgruff]

since you guys are talking o2 signals and leaning mixtures (albeit by totally different means), here's my latest off-the-wall question:

 

is there a way to modify the signal from my spfi o2 so that it leans my injector out just a hair for better mileage or will the ecu simply compensate... get confused and throw codes... get pissed and commit hari-kari?

 

my hatch is doing pretty good but with gas at $4.60/gal locally and climbing i'll do anything for mpg's. well, almost anything. hell, i'd put a goddamn sail on that thing if i thought it'd help.

[GeneralDisorder]

Well - the short answer is no... at least not to any extent that would be worth the effort.

 

The long answer is that the narrowband O2 sensors that almost all vehicles use were specifically designed to operate accurately only at 14.7:1 fuel/air ratio. Their accuracy is pretty good between 14.5 and 15.1 or so usually. They were designed this way because 14.7:1 is where the three major exhaust pollutants are at their combined lowest points. Thus they didn't care about any other ratio. The O2 is only important at idle and at cruise where it is used to acheive the lowest emissions scores. At WOT all you will see on a narrowband sensor is "rich".

 

Now - for our friend tuning is Weber this his fine - he can play with it till it's in the 14.7 range and get decent mileage at cruise and idle. That's all he needs it for. It wouldn't work if he wanted to tune max power at WOT though.

 

There are wideband sensors and monitors that can emulate a narrowband (for stock ECU input needs), and I think some of them can do scaleing and shifting of the curve - so you could probably do it that way. But you are looking at probably $500 or more for a sensor like that. There is mileage to be gained - you could lean it out at cruise to 15.5 or maybe even 16.0.... you will increase engine temps, but not drastically so. I couldn't tell you how much you'll gain, or even if it would be economically viable. There's too many variables.

 

GD

[Yo'J]

O.K. fuel/air meter installed! Looks like I was running rich a bit on idle. (The air fuel screw is quite the delicate object isn't it?) Its a little too sensitive on the first drive around the block, I think I should take it for a good drive see how it does. Maybe to Bellingham!

 

So question, some how its supposed to tell me my cruise mixture but, only if I'm not accelerating or decelerating, Right? So like on a long flat at a constant speed.

 

I don't know if Im ready for a lesson of how the jets work with the idle jets (although that might be the easy part) and the air corrector jets, the three together and the primary vs. the secondarys, but I'm willing to try if anyone else is. How does the float level get involved in there too?

 

To experiment is to learn.

I remember experimenting:rolleyes: ... and learning:rolleyes: ... and it was fun:banana: !

[GeneralDisorder]

O.K. fuel/air meter installed! Looks like I was running rich a bit on idle. (The air fuel screw is quite the delicate object isn't it?) Its a little too sensitive on the first drive around the block' date=' I think I should take it for a good drive see how it does. Maybe to Bellingham![/quote']

 

Cool - yes the only readable levels will be at idle and cruise. Also you need to let the O2 warm up for about 15 to 20 minutes before relying on it's output.

 

So question' date=' some how its supposed to tell me my cruise mixture but, only if I'm not accelerating or decelerating, Right? So like on a long flat at a constant speed.[/quote']

 

Yep - that's the idea. Flat, constant speed. 55 is a good number.

 

I don't know if Im ready for a lesson of how the jets work with the idle jets (although that might be the easy part) and the air corrector jets' date=' the three together and the primary vs. the secondarys, but I'm willing to try if anyone else is. How does the float level get involved in there too?[/quote']

 

If the float level is set correctly then you shouldn't need to change it. Only verify that it's correct.

 

The idle jet is pretty easy - if you have to open the mixture screw more than 1.5 turns you need a bigger jet.

 

As for the others - well you'll have to experiment. That's the only way I'm afraid. You can read some articles on it but they will tell you the same thing. First get your idle set - then your cruise mixture. Then dial in the rest so the progression is flat and responisive.

 

To experiment is to learn. I remember experimenting:rolleyes: ... and learning:rolleyes: ... and it was fun:banana: !

 

Right on - that's the attitude to have. I'll be hooking up my wideband to my Weber soon so I'll have a better idea of how to help you.

 

GD

[Yo'J]

Well Now I think my fuel gauge is broken! Jskddn! 188miles and just over half a full tank! Now I guess I need to figure out the rest of the readings. I'm not sure what to think of the cruise mixture. While running to bellingham at 70 along the flat it would cruise slightly rich if I was accelerating. BUT If I just maintained speed it was totally off the scale lean. On acceleration up hills it was lean aswell, well, not jamming my foot to the floor. After I got back it was Idleing a little rich. I do have some hesitation in the low end. So I'm thinking lean.

 

I'll reajust today and get a longer reading at 30-35. The hardest part of getting a reading is that I have only seen the gauge settle slightly rich or way lean. It has not ever sat stoich centered, just close on idle. If you blow on the screw too hard it would change from rich to lean. I'll count my turns out today. PS I got a cheapy sunpro with leds instead of a dial. Seems sensitive enough.

 

I just woke with a headache and might not be explaining things to clearly. I hope the air quality clears up!

[GeneralDisorder]

Well Now I think my fuel gauge is broken! Jskddn! 188miles and just over half a full tank! Now I guess I need to figure out the rest of the readings. I'm not sure what to think of the cruise mixture. While running to bellingham at 70 along the flat it would cruise slightly rich if I was accelerating. BUT If I just maintained speed it was totally off the scale lean.

 

That's pretty typical - best power is around 12.5:1 so your meter *should* show off the scale rich whenever you get on it hard. Even slight throttle will richen the mixture past what the meter can effectively read. Remember - "off the scale" lean for you is anything above 15.1:1 or so with the narrowband sensor. You can really lean stuff out at near-closed-throttle cruise because the engine is producing very low power - thus pre-detonation isn't much of a concern. The idea is to lean it out till you start getting a small amount of lean surge (you'll understand when you start changing jets)' date=' and then go back up one step richer. It's a balancing act with the primary idle jet and the primary main jet/air corrector as light throttle cruise draws on both. Then in the secondary's you want some nice rich power making jets for passing, ect. And you want a nice flat progression between the two worlds - that's a big part of what the secondary idle jet does. It assists the progression between primary and secondary main jets.

 

On acceleration up hills it was lean aswell' date=' well, not jamming my foot to the floor. After I got back it was Idleing a little rich. I do have some hesitation in the low end. So I'm thinking lean.[/quote']

 

Yeah - it sounds like you are lean in the primary's just a bit. Remember that the secondary opens at 2/3's throttle so it also sounds like you are rich in the secondary's - which is ok. What you are going to need to do is tune the primary cruise with the help of your meter and then tune the progression (secondary idle) and the secondary mains by feel as your meter can't read that far rich. Get the progression flat and the power good. You'll feel a lean condition much easier than a rich one so lean it out till you can feel it then raise the jets up a couple sizes and you should be close to the power making ratio's.

 

I'll reajust today and get a longer reading at 30-35. The hardest part of getting a reading is that I have only seen the gauge settle slightly rich or way lean. It has not ever sat stoich centered' date=' just close on idle. If you blow on the screw too hard it would change from rich to lean. I'll count my turns out today. PS I got a cheapy sunpro with leds instead of a dial. Seems sensitive enough.[/quote']

 

That's fine - just remember than the meter has an extremely narrow readable range. The "rich" section is anything from 9:1 to 14.5:1, and the lean section is from 15.1:1 to around 17:1. That's the downfall of the narrowband sensor (not the gauge), and unfortunately it's part of the design of the thing not a problem that you can fix. For what it is, and for what it's cost you, you are still ahead of the game even with the added work of tuning multiple times and it only giveing you a tiny bit of feedback. Fortunately though - the place that it does work at is where most of your mileage gains are to be found - part throttle cruise.

 

GD

[Yo'J]

Thanks GD I'm gonna drop a 150 main jet in today (the store was out of 145s) and see if it picks up better. I think, if I'm processing this correctly, that might get my fuel up a little. I'm getting a little bit of confusing info here though. I was told at the store I got my jets at that the idle jets work up to about 2500rpm and the air corrector jets work to compensate at really high rpms, I don't know what that means. Now its pretty obvious that the secondaries work over 2/3rds throttle. So what rpm s do the air bleeds affect things at? Is this a tangible figure? I would assume air would flow regardless depending on the valve/intake... speed.

[GeneralDisorder]

Thanks GD I'm gonna drop a 150 main jet in today (the store was out of 145s) and see if it picks up better. I think' date=' if I'm processing this correctly, that might get my fuel up a little.[/quote']

 

Well - generally bigger jets consume more fuel. But in the interest of getting on the gauge I think it's a good test.

 

I'm getting a little bit of confusing info here though. I was told at the store I got my jets at that the idle jets work up to about 2500rpm

 

When the throttle plates open more than a few degrees they expose the transition ports and the idle ports are no longer exposed to the low pressure area under the throttle plates. You can actually shut off the idle circuits if you open the throttle plates with the speed screw too much. It's more around 1500 RPM that they cut out. Try this - remove the idle jet and holder and then see how far you have to take the speed screw before it will run on the primary (with no jet or holder it won't suck any fuel through the circuit). That's where the idle port is no longer receiving any vacuum.

 

and the air corrector jets work to compensate at really high rpms' date=' I don't know what that means.[/quote']

 

The air corrector jets supply air directly to the emulsion tubes which introduce air into the fuel flow - they modify the fuel fow much like the screen in your faucet modify's the water flow. They make the fuel spray light and airy. More fuel needs more air to emulsify it properly. Less fuel requires less air. They do this at all RPM's where the main jets are operating. Try removing them or blocking them off and you'll see what I mean.

 

One of the best ways to understand the Weber is to play with it. Try taking things out of the equation - try the boundery conditions - no jet or at all (wide open) or blocked off completely.

 

Now its pretty obvious that the secondaries work over 2/3rds throttle. So what rpm s do the air bleeds affect things at? Is this a tangible figure? I would assume air would flow regardless depending on the valve/intake... speed.

 

Yes - any RPM where the mains are operating, so are the air bleeds.

 

GD

[daeron]

what a great thread.

 

after reading this I am very sorely tempted to see if we have a spare narrowband gauge hanging around to tap into my O2 with, just for the halibut... With the SPFI it would basically just be a confirmation on whether or not I am running at an appropriate mixture, almost like an idiot light for the correct operation of the FI, right? I know I could just try to find the LED on my ECU but thats a PITA.

[michael appel]

I have a ea82 carbed that runs 26 - 30 mpg and has a rack with tire on it the choke stopped working and the carb needs cleaned but other than that it runs and good also the engine with that many miles needs some thick oil and decent spark plugs for the loose cylinders

[GeneralDisorder]

also the engine with that many miles needs some thick oil and decent spark plugs for the loose cylinders

 

Not at all. I guarantee the cylinders are nothing like "loose", and heavier oil is only going to harm the bearings - it really won't help. The tollerances inside the EA's stay pretty much solid till very near when they blow apart.

 

GD