Weber 32/36

[LeDevil]

Ok, normally I can get Weber's to run PERFECT but I'm having troubles with this one it's a 32/36 with manual choke. It's the one I put on my truck at our Tuesday night meet for the guys who were there. I've got it to idle great, pull STRONG, but it still diesels when turned off :confused:. So I'm asking for anyones help on what to do next :confused:.

Thanks in advance Ledevil

[SHADY280]

check your timing, and idle speed again, as well as the idle mixture. those are the only things that effect it. you know the cheaters way to adjust idle mixture right? i dont know you, so dont get offended by the question. if you have a tach, keep turning the adjusting screw in and out till you find the HIGHEST rpm. that is very close to perfect mixture. then set idle rpm and timing and you should be golden.

[mklotz70]

first...I'd finish the rebuild by pulling completely apart and cleaining everything with a can or two of carb cleaner.

 

Most likely, the butterfly is not closed enough at idle. The weber adjusta a bit backwards of most carbs. I found on a buddy's weber that the secondary was not closing all the way because the plate was misaligned...might check that too.

[banzai510(hainz)]

If the carb seems to idle fine and run correctly, motor is timmed to say 10deg(IM not sure what you have I seen 7 -12deg) But if you have a L20 U67,N58 or any open chamber L20 head the motor will deisel.

 

So you can try to Run Super and see if it helps. But most likely you will need the idle cut off selinoid installed but not all Weber can get this installed . If the main idle jet brass screw is the same as the second barrel you CANNOT convert it. YOu have to leave will it or pop the clutch. YOu right when you shut down push the gas so the butterfly opens so it lessens the amout of vacuum goin into the carb.

 

If motor doesnt desiel when cold(shutting it off) then you fine and its the design of the head.REMEMBER stock L20 carbs came with a idle cut off selinoid(there is a 12volt wire) when ignition is tured to OFF a little rod plunger plugges the idle jet hole

[hang_510]

... you know the cheaters way ...

 

drop the clutch, it will stop dieseling :rolleyes:

[DISLEXICDIME]

(in Cheesy 70's Kung Fu Accent)

Come I Will Teach You A New Style It Is Called The Clutch Kill!

You Can Stop Engines With A Single Kick.

You To Will Become A Master Of The Clutch Kill Grass Hoper

[datsun dreamer]

I use that technique every time.......Hold clutch in,Turn off ignition...Then release clutch(with foot on brake!)...Truck turns off.....Works every time!

[OL YELLER]

I use that technique every time.......Hold clutch in,Turn off ignition...Then release clutch(with foot on brake!)...Truck turns off.....Works every time!

 

Well yes that does do the trick every time...BUT, (OH No, Ron is gonna do a caveat..watch it!!) what is the underlying reason for the problem?..Has to be a reason and then has to have a solution....."Clutch Kill" is effective, but, it is only a band aid........................Need to fix the problem.....(oh and by the way..I don't know what that might be...Carb? Ignition?..heck I dunno) My son says I am good at tellin ya what to do..but not good at doin it...(shoot at my age...doin it is out of the ? LOL)

[datsun dreamer]

Hey ron, I think my choke on the weber is bad...I had the carb. rebuilt over a year ago and it works very well....Just never solved the deseil problem!

[mklotz70]

well...the correct way to fix it is to put the stock carb back on because it had the fuel shut off valve. When you "upgrade" to a weber, it's a common side effect, depending on the application. I'm pretty sure it even mentions it in the weber lit I've read. Anyway.....

 

Another possiblity is carbon build up in the combustions chamber...causing hot spots that ignite the fuel. Can of carb cleaner down the throat while it's running(hot engine too) might help.

 

If you want to know if the buterflies are closed enough, put a vac guage on the tube to the dizzy's vac advance. There should be no vac signal when it's idling.

[71-521]

weber info:

http://www.carburetion.com/mixtureadj.htm

http://www.carburetion.com/Weber/adjust.htm

http://www.carburetion.com/diags/3236DGVDiaginfo.asp

[datsunaholic]

My 4X4 does that... never did it with the stock Hitachi. My '76's Weber doesn't because it has the cutoff solenoid.

 

I also found that my '81 510 does it with the stock setup ever since I put an electric radiator fan in. The bugger acts like a generator as it spins down, and makes the car run on for 5 seconds. If I switch the fan off (I have it on a toggle) before killing the ignition, no run-on.

[LeDevil]

Well thanks for all the help/info guys I've gotten it down to a small diesel now :D

[Bleach]

I always ran my idle mixture lean.

Adjust the mixture out 2.5 turns from closed. Set the speed at 1000 rpm. Then turn the mixture screw in slowly until the idle drops to 700/800 rpm. Its running lower due to lean idle. Works for me. minimal deiseling. I had a stock low compression engine though and bigger cam.

 

KA24DE don't seem to have that issue :D

[SHADY280]

if it diesels enough, you could be like that uncle buck, in that movie with that big old car. hed walk away and 30 seconds later BAM. hahahaha makes me laugh. one of the other best ways to clean carbon is with water. take a spray bottle and rev the engine a bit, spray down the carb. this works better because water doesnt ignite like carb cleaner, just dont use a hose, it only takes a little.