Topic: Weber still not quite right

[69800]

My new 22r has a 32/36 weber and I followed the weber set up to a tee. It had a little flat spot just before secondary and the mixture screw ended up a 3 turns with 55- 50 idle jets. I bumped up to 60-55 jets and it definitely better but still fill a little anemic at 1/2 to 2/3 throttle just before secondaries. Secondaries are great. Mixture screw is a about 2 1/2 turns. Tried 65-60 jets but I had difficulty with the mixture screw and had almost no room to play. Seems like it was at about 1 3/4 turns but the truck drove not well. Just did not feel as good as the 60-55 set up I have now.
Any Ideas??
thanks
mark

[YotaNate]

I can't seem to get mine right either Sir.  Idles great but weak on the primaries with a HUGE stumble when you open the secondaries.  I'm only getting 12-13 MPG to and this is with a brand new ATK long block.  My wife gets 18-21 MPG in her 86 Runner and the motor has 181,000 miles on it!  Her runner will just pull away from my 82 truck on the highway as well.  I'll be watching your thread to see if you get any good advice sir, good luck!



Nate

[kneedownnate]

Guys, I've run a weber for years and have never found a setup that totally keeps it from stumbling when the secondaries open.  I plan on rebuilding one of my aisin 22r carbs and buying the lc adapter to run it on the 20r manifold.  I've never had an issue with a stock 22r carb running poorly or having flat spots, and they've always treated me way better on inclines.

Forgot to mention, but tuned to run best I usually get the same mileage as Nate, best being 15 mpg back before california started messing with our fuel.

[69800 [OP]]

My worst mileage so far is 16.8 and I ususally get about 19 but I do not use ethonal in my truck. I drive pretty easy.

[79coyotefrg]

My new 22r has a 32/36 weber and I followed the weber set up to a tee. It had a little flat spot just before secondary and the mixture screw ended up a 3 turns with 55- 50 idle jets. I bumped up to 60-55 jets and it definitely better but still fill a little anemic at 1/2 to 2/3 throttle just before secondaries. Secondaries are great. Mixture screw is a about 2 1/2 turns. Tried 65-60 jets but I had difficulty with the mixture screw and had almost no room to play. Seems like it was at about 1 3/4 turns but the truck drove not well. Just did not feel as good as the 60-55 set up I have now.
Any Ideas??
thanks
mark

why are you changing idle jets when the fuel jets are the problem


pull the top off the carb and pull the jets out of the bottom of the fuel bowl

make sure the primary jet is SMALLER than the secondary jet

my FUEL jets are 170 and 180 if i remember correctly

[79coyotefrg]

and put the 50-55 IDLE jets back in

I can't seem to get mine right either Sir.  Idles great but weak on the primaries with a HUGE stumble when you open the secondaries.  I'm only getting 12-13 MPG to and this is with a brand new ATK long block.  My wife gets 18-21 MPG in her 86 Runner and the motor has 181,000 miles on it!  Her runner will just pull away from my 82 truck on the highway as well.  I'll be watching your thread to see if you get any good advice sir, good luck!



Nate

and what jets (idle, fuel, and air) are you running??

[YotaNate]

Glen,

  I know where the Air/Fuel jets are, not sure on the idle.  I think i'll go look again right after lunch!  I need to be getting better than 13 MPG 


Nate

[69800 [OP]]

"The secret  to understanding the critical nature of the carburetor set up and the advantages of a WEBER over other carburetors is the Idle circuit. Referred to as the low speed circuit by Weber, this circuit is responsible for 80% of the driving operation."

This comment indicated to me the idle jets were responsible for the midrange. This is why I went after the idle jets rather than the main jets. My secondarys feel great. You think my primary main jet is the cause of my problem?

I will take a look at whats in there today .. I am pretty sure the carb is factory stock.

I also read this on the http://www.racetep.com/webjettune.html web page

Idle Mixture and Fuel Mixture:
There are alot of theories about setting idle mixture adjustment on a Weber carb to determine Rich or Lean jetting....A Weber will run correctly with the mixture screws from 1/2 turn to 3 turns out...The late style DCOE carbs with the extra Air Bleed Screws on the top take 2.5 to 3 turns to operate correctly...So you cannot say that because it is 1/2 turn out that you need smaller jets....You need to find what is right for that particular engine...An engine with a strong vacuum signal will draw more fuel in with less turns of the screw than an engine with a weak vacuum signal will...This is the kind of thing that throws the "certain number of turns" theory out the window..

The Mixture screw and idle circuit is CRITICAL to the overall driveability of the car. It does not just control idle but the entire low speed running and part throttle transition. The mixture screw lets in an ALREADY MIXED volume of Fuel and Air to the engine. This is not an Air Screw. The more you open it the more mixed fuel and air enters the engine. Clockwise is Leaner and Counter-Clockwise is Richer.

The mixture screew is very easy to set whether it be a downdraft, sidedraft or multiple sidedrafts. Start with the screw or screws out 1.5 turns....Start the car and let it warm up. Set the Idle SPEED to approx 900-1000 RPM..Make sure multiple carbs are synchronized...Turn the mixture screws in until the idle starts to stumble and get rough...On a sidedraft with 2 screws do them each a little at a time....Then back them out until the best idle quality is acheived. This is a very simple operation...The car should idle well and small adjustments leaner (Turning them in) should make the idle drop off. Opening the screws more should make it a bit richer but it should still idle. Assuming you have no vacuum leaks this is a very simple process. If you cannot get a good adjustment on these screws and you have to open the idle speed screws quite a bit to get the engine to idle there is a good chance you have a Vacuum Leak and you need to fix it.

Specific Information on Mixture Screw Setting for:
32/36 DGV, DGEV Carbs. If you have to open the mixture screw more than 2 turns on a 32/36 DGV or 38 DGES your idle jets are too small...If you have to shut them below 1/2 turn they are too big....

[kneedownnate]

and what jets (idle, fuel, and air) are you running??

I've run tons of combos over the years.  I couldn't tell you what I have now, but then I couldn't even tell you what color my socks were without looking down.  Te51levin set it up initially and it was best then, but still had a flat spot and drank too much. 

[69800 [OP]]

my idle jets are 60pri and 55sec
my fuel jets are 135pri and 130sec
my air jets are   165pri and 160sec
feels abit lean first half throttle but I would not really call it a flat spot

engine has an RV torque cam, oversized valves and springs
and 2 inch exhaust

[79coyotefrg]

those fuel jets are WAY too small

the air jets are also small but not as far off
i want you to start here
 idle jets 55p and 55s
fuel   140p  and 150 s
air    165p  180 sec

[69800 [OP]]

Ok, I will order them up
thanks

ps notice my secondarys are smaller that primaries  (mains) from factory

but I will go with your suggestions of larger secondaries
m

[79coyotefrg]

its very possible they were installed backwards,  everything ive read and from talking to bud at redline weber i learned to make sure the primary is smaller than the secondary

[69800 [OP]]

ok
I will go with your recommendation

[69800 [OP]]

my idle jets are 60pri and 55sec
my fuel jets are 135pri and 130sec
my air jets are   165pri and 160sec
feels abit lean first half throttle but I would not really call it a flat spot

engine has an RV torque cam, oversized valves and springs
and 2 inch exhaust

those fuel jets are WAY too small

the air jets are also small but not as far off
i want you to start here
 idle jets 55p and 55s
fuel   140p  and 150 s
air    165p  180 sec

ok
I will go with your recommendation

Here are the results... The primarys are real nice. smooth transition. losts of power. I think I will leave them alone now.

The secondarys seemed pretty good before the change but I put your jets in . that combo felt worse. like lots of fuel going nowhere fast. so I put the  original secondarys back in.  I would say its perfect up to the secondarys but with either combo of secondarys I would say its just not worth pushing the throttle down that far because nothing really happens

[69800 [OP]]

If I go a little larger on primary fuel say to a 145... should I be changing primary air to a larger 180 also?

[79coyotefrg]

try it with just the larger fuel jet, then after a test drive try the air jet then you'll know

[69800 [OP]]

thanks