Weberized Brat still refuses to idle

[RavenTBK]

Yep yep.. stupid engine tricks. Wow.

 

While bounding down some of my favourite trails in the forest, I came across a whoop that wasnt there yesterday. Needless to say, I did bounce up and down quite hard, hitting my head on the roof. I got to the end of the trail, and the Brat died. I was able to crank it back up by feathering the throttle a bit. It has a light misfire when its not under load, and wont idle period.

 

I got it back out onto the road, and the misfire goes away when I mash down on the gopedal and go under load.

 

I got it back home and had my lovely assistant crank and feather the throttle while I peered under the hood at the pressure gauge thats installed on the fuel line. Good pressure, so I know the fuel pump isnt the culprit. With the engine running, I shot a bit of carb cleaner into the carby to clean the throttle plates and jets.

 

Still no dice. No idle, and misfire. Everything under the hood is in the same place and condition it was before..least from a visual standpoint.

 

I'm tired of messing around today, and will start by pulling the plugs, and then tearing it down tomorrow and figured I'd ask tonight. What would yall think it could be? It would save me some time if I knew specifically what to check instead of tearing it apart piece by piece.

 

De-emissioned ea81, weber 32/36..

[Skip]

Check the connection to the ADS

 

the "bump" may have dislogded it's

connector or broke the wire to it.

 

It is also possible the lurch caused some dirt

 

that had been sitting in the fuel bowl "dirt leg"

 

to become injested by one of the jets.

[RavenTBK]

I've got a weber as mentioned above, and I dont have an ADS. Wish it could be something that simple.

 

So far today, the plugs are all good as I thought they'd be, cleaned em up and reinstalled. The engine lost the misfire now, just wont idle.

 

I've ruled out the plugs/wires, and fuel filter as the causes.

 

I do think its carb related. I've disconnected the fuel line, pumped and drained the carb till I was able to blow into the fuel line and hear air escape from the throat of the carb. I blew a bit, and sucked a bit.. the air seemed to be moving fine. I shot some carb cleaner down the throat all around the venturi, and even put a small bit down the fuel line and blew it through the jets.

 

I let it set up for awhile with the throttle plates open to let all the bad stuff evaporate out so as to not start a fire.

 

Just hooked it all back up and still the same deal. No idle, but the misfire is gone after I cleaned the plug electrodes with some sandpaper and regapped them.

 

I did notice something strange though. When the engine is running at just above idle, I listen to the inlet of the carb, and it sounds a bit like when you get to the bottom of your soda from McDonalds.. you know, the straw sucking the last bit of soda out of the cup? Slurp thing. It sounds a bit like instead of making a full spray of fuel, its also passing air bubbles through the jets. Does this make any sense?

 

I've got the bottom aircleaner housing removed from the weber, and I see 6 screws that appear to be holding an upper plate. Can I remove these 6 screws to peer further into the carb without having to buy a whole new gasket/rebuild kit? I'd like some insight on how I can go about troubleshooting this without having to go through a whole rebuild. I'm broke right now, and with the Florida M&G coming up, I've gotta save what I can when I can.

[RavenTBK]

Pics.

 

DSC06859 shows the 6 screws I was referring to in the prev post.

[Skip]

Sorry, my Weber 32/36 DGEV has an ADS.

 

seen next to the bowl vent

Sounds like something is lodged in the idle jet

or an air emulsion tube.

 

I'd try a can of Seafoam in the fuel tank and

a "mexican" tune up

(rev to 3000 choke closed the carb opening)

 

Yes you can get the top of of the fuel bowl.

My gasket did not break when I tore into it.

But they are some mitigating levers on the choke linkage you must also deal with

aside from the screws mentioned.

[RavenTBK]

Nope, looked at mine again in the same spot, and I do not have one. :shrug:

 

Heh.. that Mexican tuneup is a good idea. I went out and tried it anyways. As long as the idle stayed high, it ran.. but when the excess fuel was burned off, it dies.

 

I will purchase a can of Seafoam and run it through the tank when I get it running good enough to drive again.

 

I've searched through the archives and am curious.. is there any way I can do a minor disassembly and manually clean out the idle jet/emusifier tube?

 

Tomorrow I will remove the plug for the filter screen and clean that area out. Any other things I can do?

[Nug]

Sounds like something is lodged in the idle jet

or an air emulsion tube.

Winner!

[monstaru]

funny, i was thinking the same thing...

[RavenTBK]

I've searched through the archives and am curious.. is there any way I can do a minor disassembly and manually clean out the idle jet/emusifier tube?

 

Tomorrow I will remove the plug for the filter screen and clean that area out. Any other things I can do?

 

So we all concur..but is there a way I can fix this without rebuilding the whole carb?

[Skip]

This maybe of some help.

 

Weber carbs ansuch

 

Look down the page after the install stuff

It has photos of what you need to look at

 

 

I also found this interesting, possibly taking this cap off and shoot the juice to it bruce

through it?

[RavenTBK]

Okay, while I was desperately searching for another issue, I ran across a thread that had nothing to do with what I was searching for. It told me where I can find the jets within my Weber..

 

Nothing in the other thread pointed out anything important I should watch out for, so I felt frisky and went out and pulled the top cover of my Weber to peer inside.

 

From all my other reading, I can figure out the primary and secondary mains jets, but I dont know what those three others are in the bottom of the float bowl. See attached image. (And no before yall freak out, its not real rust.. its just stains in the bowl) Which is what and what should my next step be?

[RavenTBK]

Heh.. thanks Skip! That page has plenty of useful information and pictures. Turns out what I thought was primary/secondary were really the air correction jets. I will continue reading.

 

So, I guess now that I've got it apart, I should shoot my trusty carb cleaner through all the jets just to be safe?

[RavenTBK]

Hmm.. so I pulled the idle jet in the back, shot cleaner through the jet itself, and shot it into the hole.. I saw where it dripped out on the other side. I shot carb cleaner back through its "outlet" to reverse flush it if you will.

 

Put it back together. No dice. Still dies @ idle.

 

I found a similar looking screw on the front of my Weber. Removed it.. looks almost exactly like the screw on the back. Did the same process. Put it back together. Still dies at idle.

 

Finally, I got pissed at it and physically removed the carb from the intake and set it on the trunk lid of my Honda which was parked next to the Brat. I shot carb cleaner over everything.. cleaned up the carby real nice. Upon inspection, I learned its not a 32/36, but a 26/27 (stamped on each barrel) which explains why mine looks similar to the pic Skip posted.. but is different. I found one post in the archives that mentions a 26/27.. other than that, I still know nothing about this carb.

 

edit: searching yahoo, I just learned that the "32/36" has a venturi size of 26/27.. that must be what the barrel stamps mean. i still know nothing, but want to fix it. info was obtained here

 

I popped the top off again to see the bowl and its contents. I removed each and every jet, and applying the same process as above. I then flipped the top over and inspected the connections, and shot cleaner through each of the passageways in the lid. I even wedged open the throttle plates, used the plastic straw attachment to shoot carb cleaner up the back side of the emulsion tube in the primary barrel.

 

I just finished putting it back in the Brat.. no dice. I did manage to fix the fast idle though. It idled fast, skipping beats here and there, then when the choke snapped open and the idle went to drop, it dropped all the way to 0rpm. Sux.

 

I've got a friend thats a classic VW tuner.. if I cant get this carb fixed, I'm going to contact him to see if he's got an extra 32/36 dgev laying around I can "test" with.

 

I am now officially stumped again. I know not where to go from this point. May I have some more helpful guidance?

[Skip]

Sorry real wild hair here

 

have you tried turning the main idle speed screw up until it will idle?

 

It is possible you were running on the fast idle cam

 

the jounce bumped the cam enough to allow

the throttle to now rest on the main

idle speed screw

which is set too low?

 

grabbing straws in the dark

[RavenTBK]

Turning the idle set screw to raise the idle, yields a positive result around 1500rpm. At that level, it still skips, but will hold its own. Loosening the screw to bring it back down to spec, it quickly dies out before I return the screw to its previous "amount of turns".

[swiftt]

You may have checked some, or all of the following, but I'll ramble:

 

It sounds to me like it's running too lean. Perhaps a fuel obstruction somewhere? Also check for vacuum leaks. If it won't idle, misses when it is running, and dies when you open the choke up, it all points to running very lean. Check all the vacuum lines as they are the most likely to break "instantly" as you describe (I'm picturing the spare tire bouncing and landing on the vacuum lines that run to the charcoal canister).

 

Have you removed and cleaned the needle and seat? If they are gummed up with crud or tarnish, you will get inconsistent tuning results. Also prudent to check the float level while you have it apart. I once had a VW beetle with a Solex 34PICT carb. Pulling the top and cleaning the gummed needle and seat was an annual maintenance chore or it would cease to idle.

 

Check the fuel filter and the screen filter that's located in the inlet of the carb. They are both cheap so it wouldn't be a bad idea to just replace them and eliminate them as the fault.

 

Remove the inlet fuel line from the fuel pump and blow compressed air through it, back to the tank, to clear anything that may be blocking the tank outlet.

 

Don't give up on those jets. Symptoms point to idle jets, in particular. If it runs at higher RPM, fuel will go through them but only when the volume is high enough. With this knowledge, we can conclude the jet of carb cleaner will go through too but may not be under enough pressure to release the obstruction (gasoline varnish is a VERY good glue). Another option for cleaning them would be to remove them and soak them for a day in a bucket of carb parts cleaner, followed by nice shot of compressed air.

[RavenTBK]

You may have checked some, or all of the following, but I'll ramble:

 

It sounds to me like it's running too lean. Perhaps a fuel obstruction somewhere? Also check for vacuum leaks. If it won't idle, misses when it is running, and dies when you open the choke up, it all points to running very lean. Check all the vacuum lines as they are the most likely to break "instantly" as you describe (I'm picturing the spare tire bouncing and landing on the vacuum lines that run to the charcoal canister).

Heh.. I'm leaning towards an obstruction of some kind as well. On the entire engine, theres only one real vac line, and that runs from the carb to the dizzy, which is in good shape. PCV system was removed and replaced with breather elements long before I obtained the Brat. Vacuum system, check. Its been de-emissioned, so the charcoal canister is gone. Heh.. plus, I'm running 30" tyres.. I dont have the spare under the hood. It doesnt fit!

 

Have you removed and cleaned the needle and seat? If they are gummed up with crud or tarnish, you will get inconsistent tuning results. Also prudent to check the float level while you have it apart. I once had a VW beetle with a Solex 34PICT carb. Pulling the top and cleaning the gummed needle and seat was an annual maintenance chore or it would cease to idle.

Float needle is clean.. bowl stays full.

 

Check the fuel filter and the screen filter that's located in the inlet of the carb. They are both cheap so it wouldn't be a bad idea to just replace them and eliminate them as the fault.

Fuel filter is new as of this morning, and the screen within the carb was pulled today and was found to be clean, but for testings sake, I've left it removed for the time being.

 

Remove the inlet fuel line from the fuel pump and blow compressed air through it, back to the tank, to clear anything that may be blocking the tank outlet.

This one I'm not too fond of, as at high revs, the Brat runs and pulls just as strong as it always has. So I dont believe its a flow volume problem.

 

I really do appreciate the suggestions though! What may not apply here can be applied to other issues, either now with others, or in the future with my own.

[RavenTBK]

Actually, I after some extensive searching, I've found only ONE thread that describes similar symptoms. It was done by Ratty2Austin back in April'04. There were no replies. I've sent Austin a PM asking what was done to relieve the issue. The original thread can be found here. After reading through the original thread, I went back out to peer down the barrel after I got the engine warmed up. The description Austin wrote is better than the one I did. The "straw sucking" sounds I described before are consistent with the "drippy" emusifier tube. Liquid fuel would create the same sounds in that situation.

 

I got the Brat warmed up, and to my surprise, thats exactly whats happening here. I brought out the light, and shot a short video of the inside of the primary barrel. I used a twig wedged in the throttle linkage to keep the revs up while I set up the shot. I then removed the twig and actuated the choke on and off by hand to keep the engine running while taping. You can just barely see the solid drips of fuel impacting the closed throttle plate.

 

Looks like I've found the source.. now, since there was only one thread like this...with no replies, I must ask. How can I remedy this?

 

http://latency.fjeer.us/bratdrip.mpg 3.49mb, 640x480, MPEG

[Skip]

If I didn't know better I'd say that carb was

 

"dumping"

 

Meaning flooding serious

 

If you pulled a sp. plug after it stalls is it black and wet?

 

Ever see black smoke on the restart?

 

How do you have your return line to the tank plumbed?

[RavenTBK]

If I didn't know better I'd say that carb was

 

"dumping"

 

Meaning flooding serious

 

If you pulled a sp. plug after it stalls is it black and wet?

Nope, but I will add that to the todo list at next light.

 

Ever see black smoke on the restart?

Nope. Not ever.

 

How do you have your return line to the tank plumbed?

There isnt one. Never has been one. :-\ Ran fine without it. The fuel pump, according the the inline gauge next to the carby, is only putting out 2psi. Most Weber installations I've read about this afternoon run on 3.5-4.5psi and require a return line to handle the extra volume of fuel. :shrug:

[RavenTBK]

Austin replied to my PM last night.. and pretty much said that a solution wasnt found, so he went back to the Hitachi.

 

:banghead:

So I'm still stumped.

[RavenTBK]

It was suggested to me by the local VW parts house to check the needle and seat, as the bouncing could've damaged one or the other, causing too much fuel to fill the bowl, overpressurizing the carb. He said that would be my jackpot...and if it isnt, he has no clue. Well, checked em both, nothing unusual was found. Float level is good too. I even bent the floats down a little lower than spec, and ran up the engine. Same deal, wether the bowl is full, or kept most of the way empty. Seems as though I've stumped the parts guy too. :-\

 

I've temporarily installed a cheap regulator from the parts store, and turned down the pressure to 1.5psi. Anything less and I found that it wont run at high revs either. Still spitting.

 

This thing is so freaking frustrating. I'm gonna give Redline's tech number a call and see if they'll talk to me and maybe give me a place to look. Dunno if they will, since I didnt buy the carb from them. :shrug:

 

Actually, I'm rather surpised that nobody else has replied with any possibilities. I know I'm not the only EA81 Weber out there.. the lack of replies leads me to believe that nobody else has had this ever happen to them. I know it had to of happened to someone at sometime. Wheres the knowledge?

[rallyruss]

Ok I will take a few shots in the dark. You answer skip by saying that there is no smoke/wet plugs indicating its running way rich. so I doubt its needle and seat. I have not touched webers for almost 10 years now thankfully. but when I did they were quiet often had pluged jets in a situation like this. this was when I worked at a VW shop so similar stuff.

 

now I understand you have tried to clear the jets with carb spray. at this point you may need to do a complete tear down and blow the pasages out with a rubber tiped air gun.

 

but before you do that. check somthing for me. If you still have a EGR valve on there and it gets a bit of carbon stuck under the seat holding it open you will never idle proper no matter what you do.

 

the sucking noise sounds normal to me. carbs suck.:-p

good luck hope that helps some.

[RavenTBK]

Okay.. I'm at a loss again. Today I pulled the carb back off the engine again, and took it up to my buddys shop. I popped the top, removed the jets, removed the air correctors and used a nifty rubber tipped air blow thingie and blew through the passages. I blew both emulsion tubes out, and inspected them. Completely clean. Pretty much, I was an air gun bandit.. shooting and blowing through the passages at all oddball angles. Nothing came out that I could see.

 

I got home and put it all back together, same deal.

 

Ticks me off too. This time, being the 15th time I've pulled it apart, I somehow lost the stupid c-clip that holds the choke linkage together. Apparently its aluminum, and so my sweeps with the magnet turned up nothing. Either that, or it flew through a brick wall somehow.

 

I'm gonna try once more and bend down the floats.. to see if I can keep the bowl near empty to see if that makes any possible difference.

[JWX]

u check the fuel pump or anything in the lines? could be a vac leak too. try another carb and see if that fixes it