Weber vs. EMPI 32/36 tuning....

[wildmaninid]

Hey guys. I am having trouble tuning my EMPI 32/36 carb that I got from NismoDR. I have tuned webers in the past with great luck. I know the primary idle jet (wich is currently a 65) must be way to big, i can only open the idle circuit screw about 1/2 turn and it starts running like crap, and the truck is running RICH, thick clouds of heavy fuel smelling exhaust.

 

I look down and see the primary jet is a 170 and the secondary is a 180. I guess that is the air jet that is up top? That just seems a little large as well to me, maybe i am wrong. I live at 1860 feet ASL and this carb seems jetted wrong.

 

Shopping over on carbkitus.com, it appears that weber and empi(epc)replacement jets are the same. Is that true or does anyone know. It seems like this carb is over jetted, I am wondering if anyone knows what the default jet kit is in a weber/empi carb.

 

Just trying to get some opinions, I read all through the weber tuning guide, i knew most of it, no vac leaks, fresh plugs etc. I need to get a fuel press regulator cause my pressure is at about 5psi with my electric pump and i know webers anyways want like not over 4, not sure about the spec on empi.

 

 

Other than being a fuel sucking beast the carb works great and sets up just like a weber. I just need a little advice if someone has any experience with these.

Thanks

Bill

[Cuts metal like mad]

My weber has the same size jets on my L18. Over jetted but runs fine and is 2 turns out. I have VW friends who tell me that the empi carbs are CRAP. Also, as far as I know, 3psi is the max you want on a weber, otherwise it will over fill.

[wildmaninid]

Yea, maybe too much fuel PSI is overloading it but if it was i am sure it would just force past the needle valve on the float with the truck not running but the pump on? I don't think that the carb is junk, far from it, basically it looks like an near exact copy of a weber, just made in china. Throttle shafts operate freely, choke works good, hi idle etc works great, just getting way too much fuel at idle. I guess i should correct my P.S.I before i get too much further, it just seems that 65 is pretty big for idle. In the weber tuning guide it says if you are 1/2 turn out or less on the idle mix screw and it won't run right that the idle jet is too big.

Carb works like it should and runs fine, just getting too much fuel methinks

Bill

[Cuts metal like mad]

My idle jets are 60. However, I am much closer to sea level, like 1700 feet closer! So Try a 50 or 55 idle jet. and MUCH smaller mains. You got some reading to do, unless someone here knows how to tune based on elevation.

 

This link will give you a good baseline for an L16 at close to sea level.

 

http://dimequarterly.tierranet.com/articles/tech_weber_tuning03.html

[wildmaninid]

Thats a super informative article. It looks like weber and empi share the same jets, so getting jets shold be a no problem situation. The EMPI is jetted right now as follows :Primary Air 1.70 Secondary Air 1.80 Primary Main 1.40 Secondary Main 1.50 Accel Pump 0.50 Primary Idle 0.65 Secondary Idle 0.50 Secondary Venturi 3.5 Needle Valve 2.00.

 

I have never got this deep into figuring out jet sizes and what works, all I know is i put about 45 miles on my truck and used 1/2 tank (indicated on guage) of fuel, and am leaving many many unburnt dead dinosaurs behind me.

 

I thnk i might need to get a jet pack kit or something. Weber sells a master kit, so once i am for sure that weber/empi are interchangeable, I will get that going.

 

Any more ideas/advice are welcome.

Bill

[Cuts metal like mad]

If it looks like the weber 32/36, you are almost guaranteed the jets are the same. I have actually bought empi carb parts locally in the past because they are cheaper and easier to get. I haven't used empi jets though.

 

A small engine jet kit wont come with small enough jets for you though. They dont even come with small enough jets for sea level tuning. I think they mean 2.0 to 2.5 when they say "small engine".

[wildmaninid]

I am seriously thinking of ordering my jets and emulsion tubes to the exact same spec as that article from dime quarterly. It seems like a huge change but I would really like to get the carb dialed in before winter, as I am going to be parking the 620 real soon.

 

Bill

[hang_510]

Yea, maybe too much fuel PSI is overloading it but if it was i am sure it would just force past the needle valve on the float with the truck not running but the pump on?

 

I don't think that the carb is junk, ... just made in china.

have you confirmed that its not?

 

my (dual) webers had an issue when i reinstalled them and the pressure was >4.5 PSI, as soon as i tweaked the regulator down, that problem went away.

 

 

 

made in china is synonomous with junk.

their boats are called junks...

[wildmaninid]

My fuel pressure regulator is on its way, i am at 6.4 p.s.i and i need to be down to 3 p.s.i. I am going to do that first before i go any further. Weber parts are a direct interchange with the empi, except for a couple gaskets on the body. The truck runs just as good as any weber I have ever had on a datsun (4) and everything about the carb seems a-ok. This is the first datto with an electric pump that I have had, so I think whats happening is partially my fault.

 

I don't need to be told that things from china are synonymous with garbage, I am all too aware of that fact, however I have been around EMPI sidedraft carbs before and have always been impressed with their quality.I have had webers out of the box brand new that wouldn't run at all, one had improperly tightened bolts, another had so much dirt in it the entire idle circuit was plugged, and most webers are now made in spain...........not saying much there.

 

Thanks for the advice and input

 

Bill

[wildmaninid]

Well I finally got a chance to put a fuel pressure regulator on and got the pressure dialed down from around 8 to just under 3. Truck still runs fairly rich but not as bad as it used to. I have 3 smaller idle jets ordered and next week i will play with those and see where I am at.

 

I will update here when I do.

 

Bill

[wildmaninid]

Today I recieved an array of main idle jets in the mail. I went from a 65 (what was in the carby) and tried a 55, then a 50 and have stopped at 45 for now. Idle is much smoother, the horrific rich smell is gone from idle now as well. I can definately stabilize idle enough to set the timing up right.

 

Now with my new NGK plugs and NGK plug wire set I should have the 620 purring good just in time to put her away for the winter!!

 

Bill