25 replies to this topic

[ystrdyisgone]

So I took my soob to the local "Subarus only" shop today. After the guy took her for a spin, he highly suggested a tune-up. New plugs, cap, rotor, probably plug wires too. He guessed that the plugs were shot because of the dieseling that occurs at shutoff.

Is this a correct assumption or does this have to do more with my weber carb?

A bit more info: She won't idle when she's cold. I have her "tuned" to idle at 1000RPM when she's warm. But have been noticing a skip or "bog down" every few seconds in the needle even when she's warm. Doesn't drop below 950 RPM but still noticeable.

Also my gas mileage around town is about 14 right now..

Thanks ahead of time for any helpful responses!

[El Presidente]

That idle speed is too high and probably why you are getting intermittent skips and bogs. When the butterfly's are opened to far at idle, it will start pulling fuel out of the transition circuit, causing inconstant high idle, and horrible mileage.

Your idle should be around 6-700 rpm when WARM and about 900-1,100 rpm when cold.

A tune-up helps, but you need to tune your carb for any mileage or performace increases. Theres lots of writeups and tips on how to do this, I'd search around if you have questions.

Josh

[ystrdyisgone]

Ah, good to know. I know very little about these carbs, or rather carbs in general. It appears I have to do some research.

So my problem is air to fuel mix ratio and possibly jet sizes? Because my butterfly is definitely open a bit to keep that idle speed. But if it isn't open then it will not idle cold..

[Loyale 2.7 Turbo]

If it isn't open, it will not Idle? ... That Weber could have a Idle Circuit problem, such like Dirt...

How are that Weber's Jettings? ... are Adequate for the EA82? ... Do you know the Numbers?

Mine runs on 140 on Low (Primary) Stage and 162 on High (Secondary) Stage, and I Have Awesome Mileage with my Weberized EA82, it is even Better than Stock on Highways; so I Believe that yours could have Wrong jettings.

Beside a Tune up, Something that will help to get rid from Dieseling, is to use a Complete Can of Seafoam on the Engine's intake: it removes the Carbon buildup excess, which becomes Hot spots on the Combustion Chamber and leads to Dieseling.

Kind Regards.

Edited by Loyale 2.7 Turbo, 04 January 2013 - 11:10 PM.

[djellum]

the choke is what keeps it running when its cold, tune the motor to be in spec when warm. if the choke wont work then adjust it, or just use your foot to run it for 30 seconds or so in the morning.

[ystrdyisgone]

I'm not sure what the jets are at actually. The previous owner did all the installation and tuning on it. I looked back to his thread about it, and the last I saw was that it wasn't running right, he threw a bigger jet on and then it worked. Someone said "No jetting up is not the answer!'' And he never responded. So they are probably wrong. I'll check tomorrow. It's too cold to go out there right now.

When I first got the car, that was one of the first things I did. Put a can of seafoam in through the brake booster vacuum line.

One thing I'm concerned about is the timing advance the PO set up to make it run, could that be causing rapid carbon buildup in the engine, such as on the valves, etc?

I know very little about this stuff, but have read enough on the board to guess that something, if not many things, are wrong with the way it is set up.

[92_rugby_subie]

Beside a Tune up, Something that will help to get rid from Dieseling, is to use a Complete Can of Seafoam on the Engine's intake: it removes the Carbon buildup excess, which becomes Hot spots on the Combustion Chamber and leads to Dieseling.

Kind Regards.

Do you do this by dumping it into the Carb? I was gonna ask if this might help my issue...

[El Presidente]

Yes some research will help, before you start confusing yourself with jets, air correctors and emulsion tubes, learn how to tune your carb. If you need to bump the idle to keep it running why cold you need to adjust your choke, which is common when winter rolls around. There are hundreds if not thousands of threads about this..Learning how to work on carbs can be intimidating, but when you wrap your head around how they work, you'll realize that what makes them work is really simple and when you get the theory down, you can quickly adapt your skills to other carbs.

When you run a weber, you can advance your timing well beyond factory specs and get great low end torque out of it. I think I had mine a 16 degree advanced..maybe 18 degrees, been a while...

Josh

[ystrdyisgone]

Alright, digging into some Weber threads now.

One last question, just so I can start tuning with everything else in place already, what jets would be recommended for my altitude? 4500, sometimes driving to 8000 to go snowboarding.

[El Presidente]

Alright, digging into some Weber threads now.

One last question, just so I can start tuning with everything else in place already, what jets would be recommended for my altitude? 4500, sometimes driving to 8000 to go snowboarding.

Search. I've seen a couple good high altitude threads, but don't obsess over jets yet...even the sea-level recommended jets will work at your altitude, just not as well as slightly smaller ones(don't ask which ones, it depends). Once you learn how to tune the carb, you'll understand how to tune the jets.

Webers are a little complicated for a beginner, but they are great carbs once you figure them out. If your stumped let me know

Josh

[djellum]

even in the weber books and tuning guides they say you have to run it and see how it does to adjust jet sizes. theres no "right" jet just ballparks to get you close. you need to tune it as much as possible in its current condition to find out for sure.

when people talk about "turns" they mean from seated or bottomed out, so 2 turns means two 360 degree turns from bottomed out. always count the turns you do so you can recreate or go back to where you started.

first thing is just get it adjusted properly to run when warm. warm up the engine to operating temp and turn it off.

from my weber book -

back off the idle speed screw till it doesn't touch the throttle mechanism, then turn it back in till it barely does. then give 2 full turns to set the throttle speed.

turn in the mixture screw until it bottoms out (be extremely gentle, just till it stops or you can mess up the little seat inside), then turn it back out 1 full turn.

once its running at these settings adjust the idle speed to the recommended speed (750ish for our cars if you have a manual, little higher for auto). then adjust the mixture screw till it operates and the highest smoothest rpm. repeat as needed. dont get carried away, just get it running smooth and drive around the block to see. if your more than 2 turns out on the mix, or less than 1 turn out, then you may want to check your jet sizes.

after you get it running right when warm you can work on the choke, rather pointless before that.

[Loyale 2.7 Turbo]

Do you do this by dumping it into the Carb? I was gonna ask if this might help my issue...

[THREAD HIJACK] I Suggest to use the Brake Booster's Vacuum hose to the Intake, pouring it Slowly while the Engine is kept around 3K RPM's. [/THREAD HIJACK]

... When you run a weber, you can advance your timing well beyond factory specs and get great low end torque out of it. I think I had mine a 16 degree advanced.. maybe 18 degrees, been a while...

Yes, I Run my "BumbleBeast" @ 20º without Issues, despite the Under-The-Hood Sticker says 8º +/- 2º

Kind Regards.

[ystrdyisgone]

Alright I did some reading, from THE weber thread in Offroad, and from the Manual I downloaded from Loyale 2.7 Turbo a while ago(Thanks by the way:headbang:)

I get the basics of doing the quick tune. Which I will be doing tomorrow morning. I have an electric choke on mine. My understanding of the choke adjustment is that its just turning it one direction or the other? Opening or closing the "choke plate?" as needed to compensate for idle?

[Loyale 2.7 Turbo]

... the Manual I downloaded from Loyale 2.7 Turbo a while ago (Thanks by the way:headbang:) ...

You're Welcome!

The Choke Must be completely open when the engine is already Warm, I Mean at its Normal Operating Temperatures; if the Choke remains close or it doesn't fully open, it will cause an increased Idle and Fuel Consumption.

Kind Regards.

[ystrdyisgone]

Okay, so after doing a basic tune, and warming up the engine fully, how do I go about ensuring that the choke is in the correct position? Sorry for all the questions.. I'm doing research, but not quite finding the answers I'm looking for.

Also, one other thing to note. I've been reading about this "High idle" mode, and also saw it in action in rugby_subies' recent video. Mine has never done this.. I've always had to turn the key while pumping/feathering the gas pedal to get it going.

Edited by ystrdyisgone, 05 January 2013 - 03:21 AM.

[Loyale 2.7 Turbo]

Well, about Electric Choke on Weber Carbs, I Agree with GD:

+1 on the manual choke - I really prefer them on the Weber.

The electric's are alright but seem to want adjustment seasonally and are never quite perfect. I set the electric's a little light (so they pull off quick and don't affect mileage as badly) and then allow them to warm up for 60 seconds or so on the fast idle before driving. Not a huge deal but I still don't like them.

With the manual I just set it, start it, maybe add a fine adjustment, and I'm off. No fuss. Plus the installation is easier and they fit better - not at all close to the distributor cap on the EA81's and don't interfere with the PS on the EA82's. All around a cleaner, easier option.

GD

But I Ended completely Removing the Choke from my Weber, it isn't needed here, at the Caribbean.

... how do I go about ensuring that the choke is in the correct position? ...

make sure the choke is closing when the engine is fully cold, and have the air cleaner off looking at it as the engine is warming, the choke flapper should open slowly as it warms up and stay open fully. there is adjustment on it too.

My newly rebuilt weber arrived with the choke coil in BACKWARDs, so as the engine warmed up, it actually was pulling choke on (closed). ...

I Hope that Ideas could Help you.
Kind Regards.

[ystrdyisgone]

Sounds like I should look into getting a manual choke...

I did the quick tune today, got it running as well as I am able. The throttle butterfly is no longer slightly open at idle, only problem is that it idles at about 450-550 when warm. I can't adjust idle screw because that just opens the throttle and kills my mileage, and the mixture screw can't be changed from 2 1/4 turns out because it either slows the idle or begins to run rough.

NOW do I look into changing jets? Or is there something I'm still missing?

[djellum]

you need to get the idle up to 750 before you can adjust the mixture. the idle screw will open the butterfly a bit, thats exactly what its supposed to do.

set the mix back to 1 turn and use the idle screw to get the idle up. you should adjust the mixture a little and then compensate with the idle screw to keep it around 750. up or down 100-200 rpm and reset idle.

the idle screw wont do much to your mileage by itself, since its only at idle and doesn't affect anything while your driving. it does affect the mixture it takes to run at idle, which throws off what it is while driving as well. up to 3k rpm or so your running on the idle circuit and the mixture you set it at.

[ystrdyisgone]

Alright, I believe I'm beginning to see the picture here.

Thanks for all the help djellum and loyale!

[ystrdyisgone]

So I still have to work on the choke, but I think these settings are about right? I took it for a spin and noticed a drastic improvement. Not as sluggish as it used to be. Not that I do this often, but when accelerating say in 3rd, but starting at only 1500RPM it doesn't sputter and kick like it wants to die(it used to).

I put in new spark plugs yesterday, it no longer diesels on shutoff.

I know that my cap and rotor are fairly worn, as well as the spark plug cables being very old, so that might have something to do with the rough exhaust? New parts should be here on tomorrow.

Here's a video:

[djellum]

if you think the cap, rotor, and wires are worn then you definately need to check into that before you can tune real good. that could easily be causing the bobbing in the rpms.

whats your timing set at?

sounds pretty good. what you may find if your mixture is off a little is that it will pull good at low end, but run out of power at the top, or the other way around.

[ystrdyisgone]

I know the cap and rotor are worn, just waiting on the parts to get in. The plug wires come apart every time I take them off the plug(the clip stays on the plug) So yeah, I'll be retuning after, just thought I would try to get it somewhat correct beforehand.

I am not entirely educated on timing, so I am unsure how to check what it is set at. Will do some reading.

It feels pretty good on both ends actually, compared to what it was.. Looking forward to getting the new ignition parts in and really dialing it in.

[rdweninger]

You check the timing with a timing light. It hooks to battery positve/negative and then an inductive clamp over the #1 plug wire. The light will flash every time #1 cyl fires. You point the light at the top of the flywheel and will see the timing marks. You should check your local parts store to see if you can 'borrow' one. If not... they should know some old timer who has one. Good work... keep it up.

[old sub freak]

Yes keep it up.It just gets better and you did it all your self...Think of the cash you saved.....So I just put a new weber on my wifes 88 Dl wagon.The install info mentioned fuel pressure 3 PSI MAX.. 2 psi good...now its been years since I checked fuel pump pressure with a vacuume guage,A vacuume guage??? Yes.. the opposite of a vacuum guage is a fuel pump pressure guage. So has anyone ever checked there pump's pressure or put a fuel pressure regulator??? I thought lighter pressure might give better MPG...mabey??? so anyone adjusted there pressure??? thanks,Todd OSF

[old sub freak]

Well I was told by Loyale 2.7 that all carberated fuel pumps only put out 3psi max. so mine should be fine.Thanks 2.7 !!...I got it all tuned in and the fast idle for cold weather works good,not to fast ..just right.Her car is a DL so theres no tac.I had to set it the old fasion way.. and using a vacuume guage helped alot..C ya,OSF

Edited by old sub freak, 22 January 2013 - 01:01 AM.
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