Unable to restart Daily Driven '79 620 l20b

[Mitchell]

Is in the same as the resting position of accel pump arm which is up? If it is, then it's stuck up, but I can push it down and it returns up

[banzai510(hainz)]

in the diagram I provided the lever or arm is a slot that gets pushed in to push the diaphrame in. Look closely and you should see something get pushed IN.

the other up part or whatever  Now I assume you have a Weber carb.

[banzai510(hainz)]

If you have a stock carb I guess it up or down on accell pump. I assume you had a weber cause most stock carbs or just plane worn out by now and a rubix cube to put back to gether

If you have a weber coming then its a good news thing. but on a emission filled L20 its a Mofo to get at the bolts

 

datsunmike might be better on stock carbs and maybe a acell fix(photo)

Edited May 8 by banzai510(hainz)

[Mitchell]

It's an authentic Weber, but 32/36 DGEV no slot visible, has an arm that rest upward in a horizontal position, but pumps downward while pushing on it and springs back to horizontal position. Non emissions, A87 head, header with Offenhauser intake...

Edited May 8 by Mitchell

[banzai510(hainz)]

on side of weber #34  you see the 4 little screw that hold the SQUARE this is the accell pump  you see the metal piece in the slot move in and out when you cycle the linkage on the downward stroke.

[banzai510(hainz)]

https://video.search.yahoo.com/search/video;_ylt=Awr4_vFbK_5plQIABYFXNyoA;_ylu=Y29sbwNncTEEcG9zAzEEdnRpZAMEc2VjA3Nj?mkr=8&fp=1&p=weber+car+accell+pump+operation+video&fr=yfp-t-s&turl=https%3A%2F%2Ftse1.mm.bing.net%2Fth%2Fid%2FOVP.KJ_EK0zeeUb-NEHFNw3LwgHgFo%3Fpid%3DApi%26w%3D296%26h%3D156%26c%3D7%26p%3D0&rurl=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DEz3k7bD4_2c&tit=Weber+32%2F36+Accelerator+pump+issue&pos=21&vid=a5bfb16ac764d5a32f22351ce1e5994f&sigr=CfU93yXQClwe&sigt=oOmSveADpcJG&sigi=Db6yT_vXsnBX

 

[banzai510(hainz)]

go to 13mins in vid and youll see him instasll accell pump and see the sloted arm go into square housing. this can get stuck in the IN mode and not release.

https://video.search.yahoo.com/search/video;_ylt=AwrO.iThK_5pmHYBog_7w8QF;_ylc=X1MDOTY3ODEzMDcEX3IDMgRmcgN5ZnAtdC1zBGZyMgNzYi10b3AEZ3ByaWQDdjR3dnptRlFRZDJrOWFMSmxmVS5ZQQRuX3JzbHQDMARuX3N1Z2cDMARvcmlnaW4DdmlkZW8uc2VhcmNoLnlhaG9vLmNvbQRwb3MDMARwcXN0cgMEcHFzdHJsAzAEcXN0cmwDNDEEcXVlcnkDd2ViZXIlMjBkZ3ZjYXJiJTIwYWNjZWxsJTIwcHVtcCUyMG9wZXJhdGlvbiUyMHZpZGVvBHRfc3RtcAMxNzc4MjY1MDc4?p=weber+dgvcarb+accell+pump+operation+video&fr=yfp-t-s&fr2=sb-top&rurl=https%3A%2F%2Fwww.youtube.com%2Fwatch%3Fv%3DrNJXS4GKZCk

 

 

go Im done for today

[Mitchell]

It seems to move freely, doesn't appear to be stuck? After I push it down it springs back up. Also checked the linkage and it operates ok.

Edited May 8 by Mitchell

[banzai510(hainz)]

yes where your finger is pulling down on that the pump should squirt gas in there. Usually it will leak if diaprame torn as in the video I just sent.

 

I would take it Acell apart and get another one and swap it. Or just look at it. this is EZ to do and you dont have to take carb off. If that dont work Maybe there is not enuff gas in the sytem.

 

just make sure it idles then you know gas is getting to the carb. maybe the needle valve or float is low Im only guess now.

 

just think of a Plastic cup with lid and straw that full of water and you squeez the center. the over flow comes out the straw.  either there not enuff gas in there to push out the top cause the needle valve  not letting the bowl get full enough.

 

[Mitchell]

Thanks again, when the truck broke down it was and is sitting 300ft away from my garage on a dirt driveway. 20 years ago, I was able to just bolt this weber carb on and it ran very well right out of the box, I'll just wait until Monday for the new one to get here rather than take it apart on the dirt.

[banzai510(hainz)]

put a plastic tarp under and go for it. this is how you learn to trouble shoot

 

FORTUNE FAVORS THE BOLD

Edited May 8 by banzai510(hainz)

[Mitchell]

I'll let you know what I find...

[banzai510(hainz)]

hopefully there is gas coming out when you take that cover off. if NO gas then most like not the pump diaphrame.  but the diaphrame not filling up with gas. ck the float setting /needle valve.

 

can fix this w/o taking carb off the manifold

Edited May 10 by banzai510(hainz)

[banzai510(hainz)]

did you pull the accell pump diaphrame from the side and gas come out???????????

[Mitchell]

not yet, can I pull it after taking the carb out of the truck, it will be much easier?

[banzai510(hainz)]

 You can do it with the carb on manifoldLike I said you can put a tarp under the truck incase you drop a screw but. start it or crank to get gas up there . then shut off and pull those 4 screw off and gas should come oout kinda like in that 1st vid it was dripping gas.

then you know you have fule in the system. ck the diaphrame. If looks good put it back on. If no gas come pouring out I would look at the needle valve being stuck not letting enought gas in.

 

 

But Im goin by your last major post . NO GAS SQUIRTING in maine barrel when linakge is cycled.

 

 

the 4 screw to pull it are right there, you got lots of room. Why pull carb off if you dont have to.

[Mitchell]

I ran it again today and was able to drive it to my home, of course slowly under 2100 rpm. So now the truck is on a concrete driveway and within reach of air tools and electricity. I verified while it was running and immediately after shutting it off, that it will not squirt fuel. I also checked my plugs and they looked like it is running very lean, white in color, but they are new set of plugs... The new carb just arrived, so that's why I thought about doing it with the carb out of the truck since It would just be much easier to access the 4 screws, but doable if necessary while on the manifold. I would like to know if the diaphragm is cracked or torn so if it matters, I'll take the accelerator pump before removing the carb.

So, does it matter if I check the accelerator pump after taking the carb out?

 

Thanks

Edited May 11 by Mitchell

[datzenmike]

If plugs are light or white then running lean. Primary jet has dirt in it. 

 

Accelerator pump needs to be working but this is not the reason it won't rev above 2,100. 

[Mitchell]

Thanks Mike, I'll be putting the new identical 32/36 carb on tomorrow morning, should be interesting...

[Mitchell]

New carb installed easily and it started right up runs a noticeably smoother, revs a little bit higher to 2500 (from 2100) and idles smoother, but not revving beyond that without popping. My timing is verified good, the truck starts very good. I'm back to looking at the distributor possibly not advancing or shorting internally? I have sent my recycled unknown matchbox distributor to Jeff at advanced distributors to be rebuilt with good parts, but it will be another week before I get it back...

Edited May 12 by Mitchell

[datzenmike]

Vacuum advance has nothing to do with revving up. 

Second carburetor same pretty much eliminated the carburetor. Unless the adapter is leaking vacuum from bad gasket or is cracked. 

 

 

Check ignition timing 12^0.

 

Check distributor cap not cracked and rotor or cap not carbon tracked. Check coil high voltage outlet is not carbon tracked or cracked and sparking to the - terminal. Carbon tracking is a thin line often looking like a crack where the insulation has broken down and the spark takes a short cut along the surface to ground. Once there it's easier and easier for the spark to jump. Shitty picture of my coil with faint crack and spark arcing to the ground terminal.

 

 

Check your valve lash. If nothing then probably needs a valve job.

[Mitchell]

Thanks very much, Carb came with a new gasket. I will check each item you've mentioned, it just started raining so it will be a little while. I had checked valve lash last week cold and found only number 4 exhaust was too tight. At least now I can check them hot...

[datzenmike]

Often, solving any problem is a process of elimination and it takes time. However, every problem is a teacher and you amass knowledge that help with future problems. It's like being a detective.  

[banzai510(hainz)]

22 hours ago, Mitchell said:

I would like to know if the diaphragm is cracked or torn so if it matters, I'll take the accelerator pump before removing the carb.

I MYSELF would just like to know if there is gas behind the accell pump.

 

I have changed accell pump diaphrams with the carb still on. This is NOT hard Bushmen in africa do this with landcruiser all the time..  Just to let you know the I lay money the carb is most likely fine just the pump/needle valvef/float or dirt.

Its a perfect trouble shooting experiment.

 

Like the video or I said before if the acell pump torn it would leak gas  coming out the side. It DONT leak gas but doesnt squirt gas. So maybe no gas in the bowl or not high enough

[Mitchell]

or maybe one of the internal emulsion tubes is partially clogged. Since the new carb is doing about the same thing it must be something else... Maybe too much distributor shaft play, causing higher rpm arc?  or burnt valves? It started pouring down rain here, I'm going to do a warm compression check and check valve lash hot this time, check timing again and see where those are at...

Edited May 12 by Mitchell