Pretty Unique, Huh?

[strat1960s]

I hate replacing parts as a way to troubleshoot a problem, but that's what I am going to do.
I have been reading Cobrsix's posts about jetting his carb, but becasue the Weber 38 seems to be a different creature, I am not sure how closely I can follow it.
Here is the problem that I have.
1. I can't get the motor to idle at all
2. In order to keep the motor running, I have to keep my gas pedal about 3/4 of the way to the floor.
3. After shutting the motor down, I have a puddle of fuel sitting inside the intake.

Here is the conclussion I have come up with:
The Isky cam-shaft is tricking the carb into thinking I am running wide open causing my flooding condition. I have asked around, and have been told to re-jet and replace my power valve. I was told that there is only one size of power valve for the Weber 38, so I may be replacing a perfectly good power valve, but this is the only way I can rule out the power valve. I have ordered a power valve and jet kit for the Webber 38 DGAS carb.
Has anyone re-jetted a Weber 38 DGAS? Can you offer some suggestions?
Thanks.
Ted

 

[CobraSix]

I think your center carb or your fuel filter may be clogged.

My carb did that once and it would idle below 2000 RPMs. Ended up being something clogged in one of the carb passages. So, try swapping or cleaning your filter or try swapping one of your outer carbs to center to see if the problems is still there.

That will cause the other two issues that you mentioned.

Slade

 

[strat1960s]

Cobra,

I am running only one 2bbl carb on my Aussie Head. I don't have any other carbs to swap with mine to see if the carb is acutally the problem. As for the carb's fuel filter being clogged, it is possible, I have a pre-pump filter, a pre-carb filter, and finally, the filter inside the carb. I will check the carb's filter. It's washable, so if it is dirty, I will clean it out. The filter I am running between the pump and carb is clear, and it appears to be clean.
I will keep working at narrowing it down either until I have replaced everything under the hood, or I finally fix it.
Keep your fingers crossed for me.
Thanks for your help.
Ted

 

[CobraSix]

Sorry, with all the people running new set ups, I was thinking for somereason you were running the Offy.

Same thing applies. It happened to my 1100 just like your described. Happened all of a sudden, 15 minutes of driving down the road and it wouldn't stay running anymore.

One other possibility, with all those filters...you may be lossing too much fuel pressure at low RPMs. Just an idea.

I only have the fuel pump filter. I got rid of the inline filter.

Slade

 

[rbohm]

8) since you have fuel puddling in the intake, you are definately getting too much fuel. if the power valve is set up to open at too high a vacuum, that will be part of the problem. high float level and high fuel presure also cause the same thing, as does an internal leak in the carb.

 

[strat1960s]

RB,

Is the power valve on a Weber 38 DGAS carb adjustable?
I am using a fuel pressure regulator. In fact I have it set at 3 PSI. I could try a lower setting, but don't think the fuel pressure is an issue at this point.

Thanks.
Ted

 

[rbohm]

8) depending on the type of power valve you have, it is either replaced with one that opens at a lower vacuum rateing, or you change the spring pressure so that it opens at a lower rating. the holley power valve, for example, you change to one that opens at say 3" of vacuum instead of 6" to delay its opening. the edelbrock valve you would lighten the spring pressure to delay the power piston from pulling the rod out of the main jet keeping the fuel flow rate lower. i dont recall which power system the weber has off hand.

 

[strat1960s]

I just got my Weber 38 DGAS jet kit and power valve yesterday. While I was talking with the tech-support guy when ordering my jet kit, it seemed as though he was saying that there is only one replacement power valve for this carb. If I remember correctly, he did not say specifically, but more along the lines of this is the (only) replacement part number. I have heard each power valve has a specific setting, and some power valves can be replaced with valves of higher and lower settings, or they can be adjusted. Does anyone know for sure if this is possible with the Weber 38 DGAS carb?
I will start working on the carb this weekend, as time allows.
Thanks for your help.
Ted