38 Weber / fuel pressure question (2 Viewers)

[Anvil]

Don't see a crack. There's no vacuum leak.

Plastic floats.

I'm going to pull the carb and send it to Bob Pauge at Weber for a rebuild. There's something I'm obviously missing... I've been looking at it too long. Need another set of eyes to evaluate the carb.

The carb has run flawlessly for almost 6 years, I don't mind buying a new one if need be.

 

[Weber Sarge]

Ok , let me know how it goes . I was gonna have you send it here , just pay return shipping/parts if needed .
Sarge

 

[Anvil]

Hey Sarge, I'd love to send the carb to you for a rebuild!!! I'd really like to learn where/how I screwed things up! I'll send you a message a later.

 

[Weber Sarge]

These days , just cleaning and inspection here , nothing deep .
Sarge

 

[ErikinSC]

@Anvil - have you resolved your issues?

 

[Anvil]

ErikinSC, yes, for the time being the issues are resolved...

I replaced the electric fuel pump with a Kyosan mechanical.

Replaced the HEI with a trollhole dizzy.

Replaced the old Weber with a new 38 dges Weber. Was going to go with a Trollhole carb, but they were out of stock, and I didn't want to wait.

Just ordered a fuel regulator kit from LC Engineering, http://www.lceperformance.com/Fuel-Pressure-Gauge-Kit-Low-Pressure-Carb-Only-p/1035056.htm. Hoping to fine tune the Weber a bit once this is installed. I still think the fuel pressure is too high.

The engine is running fine now, no more flooding or back firing. My only complaint now, is the engine doesn't start as quickly as it once did. Prior to the flooding issues, the engine would start with the slightest bump of the starter... now it takes several revolutions of the crank before she starts. But at least I am now and !!!

 

[ErikinSC]

Well, at least your motor mounts were still good! JK - Im glad you found and solved your problem.

I'm HOPING that I do not have to replace my OEM mechanical pump (4 psi O/P pressure, measured) but have read that 3psi is all that is req'd. I used @Weber Sarge suggestion to install a second fuel filter, a vented CJ style inline just before the carb. I think that will relieve the extra pressure, if it is an issue at all. @Trollhole is upsate in S Carolina - I've gotta make a road trip one of these days to see his stuff. LOTS of good feedback. I ordered a Weber 38 rebuild kit today - but my Weber is only a year old. I'm hoping I find trash in it ... so I can find and fix my problem. Gonna break it down tomorrow after work...

I've always just pumped the accelerator pedal 2 times before starting... works well for me so far.

Most important thing is - you're !!!

 

[Anvil]

Well, at least your motor mounts were still good! JK - Im glad you found and solved your problem.

Now that's funny!

I read your thread... good luck with your problem! I tried the CJ bypass filter idea... it made no difference on my engine.

I've tried different methods of starting the engine... pump once, pump twice, no pumping... still hard to start. Once the new regulator is installed, I plan to tune the Weber a bit and see what happens.

I see you're in Summerville. I lived in that area in the 80's while stationed on a Fast Attack Submarine in Charleston... many fond memories of the region.

 

[ErikinSC]

Now that's funny!

I see you're in Summerville. I lived in that area in the 80's while stationed on a Fast Attack Submarine in Charleston... many fond memories of the region.

I qualified here on the Sturgeon... Fast and Black, 1 screw, 1 crew ! I did 6.5 because it had become just a job, not an adventure. Miss the good people I served with.

 

[Anvil]

I thought you might be a Bubble Head!

I've been on the Sturgeon, though I was assigned to the Grayling SSN 646.

Think I'll take my 40 for a relaxing Friday afternoon drive...

 

[1chukar]

I'll warn you in advance - unless it's an older regulator none of them work very well with the Weber , it needs a steady low 3psi or even less offroad . All the newer low-pressure pumps are about as reliable as a Yugo , although there are/were exceptions . Best route is to use the stock mechanical pump and either tap the carb's inlet head (very tough to do it right without wrecking it ) or use an inline bypass filter . I have built brass bypasses that had provisions for using a Weber main jet to regulate the flow and they worked the best . There are bypass type regulators but decent ones cost more than a new carb . Just be careful about placement of the filter and heat , route the return one way or another back to the tank - best and easiest solution .
Sarge

I am very grateful for coming across this solution as it really had a positive effect on my ‘74 with Weber 38. Changed start up, idle, removed intake backfire. Next move is to dump the electric pump and reinstall the reliable mechanical one.
thanks Sarge!!