If you feel this is not right, feel free to move this.

2.2L with weber 32/36 DFEV carburetor in a caravan with 3 speed automatic. I'm trying to tune for MPG but I'm banging against wall. Ingition is controlled by the computer (ancient one). Weber measures their jets in mm.

primary is what giving me hard time. The secondary is done, I got it right for full power 75% thru WOT range mixture.

I can start this way:

Idle mixture is no problem and excellent idle.
Idle jet is a pain. I either have to go fat to kill the bucking when I crack open the throttle to take off same thing go slowly n' gentle. The seperation is only 5 clicks apart. Jet .060mm is wild bucking while .065mm only have a rememnt of it.
BUT, both .060 and .065 is way too much rich when butterfly's edge is or past transfer slot when I'm at speed between 10km/h to 45km/h, also often is while at 50-60km/h speeds. That where is I have not yet reach sufficent air velocity for venturi to come online.

When I transition to venturi, either way I go extremely lean (but no surging but lose power) or start rich then it leans out some or way all the way to the extreme lean when vacuum builds stronger while van comes to specificed speed while holding throttle at same position.
If I change a jet, I either stay rich or if I step 1 one way, too lean. Out of control.

Can the old computer interfering with this tuning? There are no leaks because I can hold a idle at any speeds no problems.

SIGH! Cheers, Wizard

First, what are you calling rich, and what are you calling lean ( 11.0 - 13.5 ) ?

Are you using a wideband O2 sensor to test with ?


What air correctors you running ( secondary and primary) ?
What idle jet you running on secondary ?
What main jet you running on the secondary.
What number Emmulsion tubes you running S & P ?
How much vacuum does your engine have at idle ?

And yes the computor controling the timing, but not giving what you need can cause some of your problems.


On the Weber the seconday can effect idle, cruise and tip in of the primary's.


Sorry for so many questions, but you did say Weber, and the word tune didnt you .



Jess

As I speak, just had little shopping around for O2 wideband sensor and was fortune to get one for 70.40 cdn locally so I'll get it on next paycheck. The fillup is now 60 bucks and expected to rise so that is motivation enough.
I have already receviced JAW controller (google for it) and soon will assemble it. The Innovate wideband kit is pricy. around 300-350 locally, this one I'm assembling is appox 55 kit with shipping and 70 dollar sensor.

The setup:

S & P emulsion tubes are F6. I have other sets of F50 and F66 I think.
primary: idle jet 65
main 123 (took from a holley, it's in mm for sure).
air corrector 140

secondary: idle jet 50
main 145
air corrector 155

Weber 32/36 DFEV is mechancial progressive 2 barrel so the secondary have no effect till more than 50% throttle opening.

The gauge is narrow band 20 LED in a arc and narrowband O2. I'll be replacing this and calibrate the wideband controller's output to work with this gauge after I characterize the gauge on the lab power supply with variable voltage divider.

Cheers, Wizard

Hmmmm, fun with the Weber. I am still fiddling with my 32/36 on a Slant Six, using the butt dyno because I have been to lazy to weld in a bung and use an O2 sensor. There are some websites that you might find helpful:


Stock jetting sizes are here:

www.triumphspitfire.com/jets.html

Other peoples experiences:

www.zeebuck.com/bimmers/tech/dgvjetting.html

http://fordsix.com/forum/search.php (search for Weber 32/36)

If I had to guess I would say your main jet might be too small. The stock Weber 32/36 DGEV build is for a 4 cylinder 2 liter Ford engine and it uses a 140/140 Main/Secondary fuel jet setup. Perhaps you should give that some thought. Jet recommendations are tough to give from afar since even engines that are the "same" will perform slightly different with the same jettings--the A/F meter and a stopwatch are your best bets. A chassis dyno is the ultimate, but they are just a little difficult to find and they are not cheap.

Have you checked the float settings? If not, then please do it. I figured that mine was just fine since it was a brand new carb. Negative on that! It has a plastic float, which was set at the brass float setting--not good! I suppose it was the new guy assembling the carbs that day... Anyway, night and day difference with the proper float setting. Now all I am doing is tweaking the secondary so I can accelerate in O/D going up a rather steep hill in my area--a large improvement over the hopeless 1-bbl that the mice had nested in.

Typically, with a A/F meter you can sort out the primary with almost no pain--the secondary is a bit more difficult because you really need to be romping on it (note: got pulled over on a country road for "racing", got a warning because I had the red "Jet-Pac" in my hand and the guy had a Weberized rig of his own).

Good luck!

_________________
Slanted D150

FLoat level is spot on. It doesn't have the surging (of too low level) or anything weird with too high float.



Oh, did a vacuum test with gauge and vacuum hand pump on the spark control computer transductor (big round can). Leaks medium fast at low vacuum but leaks down faster if I try to pump more vacuum Hg.

Got a good spark control computer for 2.2 or help fund me to get a megasquirt computer? Tight on money till I get car insurance paid in June.

Cheers, Wizard