38 dges carb install

I hooked up a gauge to it and I was not able to get it down to 3psi. So I then opted to buy the recommended Weber fuel pressure regulator. It is worth the money. I decided to run it off the front of the engine.

I didn't like my initial install with the fuel inlet on the carb being in the stock location of the driver's side left side. I also wanted to install a permanent fuel pressure gauge. So I drilled and tapped both fuel inlet ports on the carb top plate to accept the fuel gauge in the stock left side inlet position and relocated the fuel inlet to the right side. This is my original setup with the cheap Mr. Gasket regulator and fuel inlet towards the left side of the car.

This is my current Weber fuel pressure regulator and fuel inlet setup part number Another note: When I installed the air cleaner top plate on, and tried to snap on the retaining clips, the two clips on the backside towards the firewall would not fully clip on. I just cut a little material off the bottom tap on the clip so it wouldn't hit the carb when it went on, and that fixed it. The carb ran pretty well out of the box, once I got the fuel pressure sorted out.

But it still had issues. They say to set the float at 40mm from the gasket to the bottom of the float They showed a different style float , and the max float travel was said to be 50mm. I tried both. Neither worked all that well. I then refereed to instructions that came with the Weber Jet kit I bought.

After doing exactly this, I found the measurement to be Runs great. Weber says to screw in the mixture screws until they lightly seat, then back them out 1. If the idle mixture screw is out more than 1. I hooked up a vacuum gauge to the intake manifold to get the best reading for setting these. But right now, it runs great! I don't have any complaints at all, but if I can put the carb into better specs, then I will try. We will see what happens tomorrow. KlassicMotion 16 posts. Just bought 2 webers my self.

Installed the one on the and at start up it ran between 4K and 5K at idle Bolted it on, started it, idle is fine Kudos on the intake. This is one of the disadvantages of a weber carb swap Looks great. Great writeup. I've been running a 38 for a few years on my L20B and I love it.

But I'm taking your que on a few things that I didn't do. That pressure gauge is pimp. Perhaps not necessary, but I'm doing it. And the port matching is happening. It's definitely not too much carb for this engine. Drive-ability is great. I have absolutely no issues. It pulls hard from a stop, clear on up the Revs with no hesitation. I haven't seen just how far up the Revs it will go, but once I feel like I "know" the engine better, I will play with it more.

At first I was getting a little dismayed with the performance of the L20B, and was thinking about more performance mods or a swap, but now that the carb is tuned in better, it's fun.

I've tried to bog the engine down by putting my foot in it while under RPMs in 4th and it still pulls from there. So I've been playing with the idle air jets today. Since the factory jets of 50 were causing me to have to screw the idle mixture screws out more than 1. It sitll runs great, but now I have the right side valve cover side idle mixture screw out 1 turn. So that one is within specs.

This is the minimum spec, so it is still within specs, but right on the line. I think I will leave it for now. Putting on a good fuel pressure regulator and adjusting the float to the proper setting made a huge difference in performance.

Bumping up the idle air jets one size larger from 50 to 55 put the idle mixture screws within specs. Gotta ask cause I've been looking into it.

I'm assuming you made the decision to install a fuel pressure regulator in place of a return line. I've read that pressure regulators can put undue stress on mechanical fuel pumps. Do you think there is anything to that? I could buy into the theory that regulator may put some extra back pressure on the pump, but I wonder how much damage it could really do.

We are only talking less than 2psi that the regulator is stopping. You know, are we talking years before you notice the pump is going out, or months?? I don't know. Regulators have been in use for decades, I personally have not heard any bad things from running one. I'm not worried about it enough to change what I've got And I would put one on my next setup. I dont have a reg or a return on mine, the max weber calls for was 3.

My truck was so lean, the spark plugs were orange Fuel system setup is one of those things thats an art not a science, it all looks good in black and white till you implement it and it doesnt work for beans.

Good luck with your vehicle, also another question, are you happy with your electric choke? Also man that engine is so clean, to quote ferris bueller's day off: "he never drives it, he just wipes it with a diaper" hehe ;. Running extra fuel pressure is just going to push fuel past the needle and seat. I don't see it doing and "damage". Just flood the carburetor. I suppose you could just compensate for it by adjusting the float level.

You also put in another post that you had your idle mixture screws out past the 1. The mixture screws on these Webers are opposite what other carbs are on adjusting the mixture screws.

I only run electric chokes when I can. They are very easy to adjust the high idle on. I've never had any issues. Out is richer, in is leaner man, even my instructions that came with show that in the illustrations, maybe your model of 38 is different? So I've been running around town doing errands in the this afternoon. When I came home I re-checked the adjustment on the idle mixture screws.

The Left side preferred 1 turn out this time. I will try that for now. I also had the engine diesel once on me while I was out I want check on one thing first, then I will look into putting the switch on and seeing what happens.

Thats what i was saying that its different, the 38 has more than one screw also doesnt it? My opinion ignore weber's paperwork, just set it to what sounds best, carbs are tuned by ear, not by a instructional help packet. Turn those idle screws equally till it sounds better they have to in sync obviously same amount of turns for each mix screw.

Also when tuning it you normally want the idle speed screw at 1. If you have a vac leak it makes tuning them oh so much fun since they can have multiple personalities lol. If your engine has the shakes thats a telling sign, it should sit fairly still when running, if its acting like it needs a bathroom break then either its not getting enough fuel and too much air or it has a vac leak which is leaning your mix out unmetered.

Just in case I wasn't clear on how the fuel vapor valve flow guide valve as Datsun calls it hooks up:. Obviously the pumps 'produce' more fuel than most carbed engines can use None of my engines are starved running return lines Of course each carburetor could be set up differently from the factory for various reasons.

In addition, no two engines are a like, thus each engine will need different tuning. It's possible yours just happened to be setup correctly for your car. You can post now and register later. If you have an account, sign in now to post with your account. Note: Your post will require moderator approval before it will be visible. Paste as plain text instead. Only 75 emoji are allowed.

Display as a link instead. Back out the screw 1 full turn. Start the engine, the engine will run very slowly more like a tractor. As long as the engine stays running idle speed is not important at this point. The engine should pick up speed and begin to smooth out. Use your ear, not a scope or tuning instruments at this point.

You want to tune the engine by sound. Adjust to best, fastest and smoothest running point. Now that the mixture screw is at its best running location, you can adjust the Idle speed the screw. Check and set idle to your driving preference. Put the car in gear and apply slight load, AC on and set the Idle as you like it.

Recheck timing and vacuum hook ups. Recheck mixture screw to lean best idle again. If all is still best and smoothest idle then confirm and note the final settings. To confirm settings with the engine running. Start by screwing in the mixture screw and count the number of turns it takes to bottom out and note if the engine dies.

Also check the speed screw and note how many total turns from initial contact. You may have opened turned in the speed screw. Reset the screws back in to the best final settings Per your notes and go on a test drive.