Need help with Weber 38/38 problem..

dang

dang

Administrator
Site Donor
Messages
4,435
Reaction score
3,536
Location
Rocklin, CA
Ok, I've run out of things I can try with this Weber 38/38 I'm having trouble with. Here's the story...

I had two 38's off of a CS parts car (that was running when I bought it but I only heard it for a few seconds). I pulled the carbs off and put them on the shelf. Now, two years later, I've decided to put them on my coupe. I took the stock Zeniths off and mounted the Webers, along with different linkage and modified the opening in the manifold. The engine starts and runs but it seems to only be running on one carb. What I've done so far...

- Checked for vacuum leaks, over and over...
- It gets fuel
- New accelerator diaphragms
- I've swapped the carbs on the manifolds and the problem followed the carb
- I've swapped the tops of the carbs (floats) and the problem stayed with the body of the carb (did not follow the float).

After doing all of this it seems to be a problem with the body of one carb. I've taken it off several times and cleaned the hell out of it and to no avail. While the engine is idling you can put your hand over the good carb and it kills the engine within seconds. If you put your hand over the bad carb nothing happens (engine keeps running). If you rev the engine up a bit and put your hand over the bad carb it continues to run but your hand gets covered with fuel from the suction.

I'm hoping someone has some insight, I'm running out of ideas.

Dan
 
you've unscrewed and cleaned your idle, main, and air corrector jets? Needle valve operating correctly? Float getting stuck?
 
Last edited:
It should at least be getting fuel thru the idle circuits. I'd pull the idle screws out and blow back through the idle passages with compressed air with the top off. A good shot of air should come out the hole inboard of the idle jets on each side. Check to assure that your idle passages into the bore are clear.
Have you tried adjusting the idle speed screw?
 
I've blown carb cleaner through every orifice on the carb and it just flies out the other side of the passage. The carbs were very clean when I started and everything worked, nothing sticky, no film on anything but I cleaned them anyway. I thought I had another 38/38 to use but I can't find it. I'm at the point of putting the Zeniths back on. 8-(
 
I remember a Shop that worked on Webers in Sacramento called Factory Carb or something like that.Maybe worth getting them to look at it before giving up?
 
I just realized how close you are. I'm pretty good with Weber downdrafts. Let me know if you'd like some help. I'd be happy to swing by.

-Scott
 
I have the 38/38 Webers as well.
I hadn't owned a car with carbs in 30+ years so steep learning curve.

One of my carbs was just dumping fuel down the throat. You could see it from the top looking in.

I bought rebuild kits and followed some instructions and returned them to car. Same problem.
I took it apart again and could not find a reason for this.
I was tired of fooling with it and friend offered me a replacement carb and that one has been working ok for about 6 months.
I am getting ready to do an engine rebuild and am switching to Weber 45 side drafts so have not messed with the 38/38 carb anymore.

There is a valve in the bottom of the float bowl called the Power valve.
I remember reading where they can be a big problem with this carb.

BTW this model does not have the solenoid cut off.


I have a brand new one if you think you would want to try it?
Hard to find really good info about this particular model.
Let me know.
Gary
 
Last edited:
Well, thanks to Dascoupeguy mentioning the idle cut off solenoid I remembed that the carb with the problem had one cut off solenoid and the other side was plugged, or what I thought was a regular jet. After taking it off it ended up being just a screw with no metering tip. I can't find my other Weber to try another jet or solenoid but I'm sure that's the problem. The fuel is dumping through that jet inlet unrestricted.

I need a idle jet or solenoid if anyone has one. I'll order one online tomorrow if not.
 
I have a number of idle jets. Feel free to PM me if you want give them a try.

-Scott

dang said:
Well, thanks to Dascoupeguy mentioning the idle cut off solenoid I remembed that the carb with the problem had one cut off solenoid and the other side was plugged, or what I thought was a regular jet. After taking it off it ended up being just a screw with no metering tip. I can't find my other Weber to try another jet or solenoid but I'm sure that's the problem. The fuel is dumping through that jet inlet unrestricted.

I need a idle jet or solenoid if anyone has one. I'll order one online tomorrow if not.
Click to expand...
 
This style...
 

Attachments

  • IMAG0932.jpg
    IMAG0932.jpg
    87.2 KB · Views: 116
  • IMAG0929.jpg
    IMAG0929.jpg
    79 KB · Views: 111
You must log in or register to reply here.
Back
Top