Re-jetting (or not) the DFEV

[18Fiatsandcounting]

Todd, I will try one last time: Your auxiliary venturis could be installed backwards, and if this is the case and they were reversed, that would solve your engine problems.

Please: Take a look at those two "wing like cylinder things" in the center of the primary and secondary barrels. Like I have said more times than I care to count, THEY ARE REMOVABLE, AND IT LOOKS LIKE THEY MAY BE INSTALLED 180 DEGREES WRONG. With a screwdriver, these can be pried out, and the openings in the one side of them should face towards the float bowl. If installed 180 degrees opposite from that (very common), the engine will exhibit exactly the symptoms you describe.

For the sake of not continuing this thread forever with no resolution, PLEASE make sure that these auxiliary venturis are installed correctly. AGAIN: THEY ARE REMOVABLE.

And for the record: the DFAV should have a coolant driven choke ("A" for aqua), while the DFEV is electric driven ("E" for electric or the Italian version). Your mileage may vary.

-Bryan

[geospider]

Well, Crap, I just wrote a response and somehow it didn't go.. I wont remember all of it.
1st; dont; replace everything unless bad: power valve and accel pump, both easy to test..
also, yes, the accel pump squirts in primary only.

As Bryan said, the venturies go in a certain way. One side has a round hole and the other side "looks" like a rectangular opening. Put the round hole towards the bowls. you prob know this, but I've done stupid things that I knew, and maybe was installed incorrectly at the factory.
The jetting is not making it not run. That's for drive-ability, performance, etc.
Oh, and 2 turns out on mixture screw will get you going, but you won't stay there. I am less than 1 1/2 at almost sea level. check timing too.

Geo

[wetminkey]

I will check the venturis, but the "opening" in the center of each of the brass tubes is a long oval slot that faces downward,...
I'd rather not pry these out to see what the interior hole looks like, without knowing that I need to.
Both brass tubes, in the center of the venturis, slope downwards, toward the float bowl.

[18Fiatsandcounting]

Please try and remove one of the auxiliary venturis, as I can't tell from the picture or your description whether they are installed correctly or incorrectly. They are usually not pressed in super tight, and can be removed just by pulling on them with your fingers, or perhaps using the handle of a wooden kitchen spoon through the throttle opening at the bottom, to nudge them upward and get them started. Sometimes they just fall out if you turn the carb body upside down and lightly shake or tap it.

These venturis are meant to be removed and swapped around, and in fact you can get different sizes and shapes to fine tune your performance across the rpm range. I've played with changing them around myself, but I couldn't tell any difference. You might have to have the engine on a dyno to be able to tell for sure.

Anyway, these venturis must be installed correctly, and Geo has a much better description above than I could offer. One end of the venturi side arms has a "blind" opening, and if that is the one that faces towards your float bowl, the main fuel circuit won't work and you won't be able to rev the engine much past idle. The side arm that has an opening that connects to the brass tube opening is the side that should face the float bowl (center of carb), when installed correctly.

-Bryan

[wetminkey]

These won't budge without damaging the carb body.
The carb is brand new, and I doubt that the venturis are installed backwards,...I'm tired of everyone guessing, without any diagnostics.
How about if you guys just check your stuff, and let me know what you find out?! Both are installed the same way, and the brass tubes slope downwards toward the bowl - I cannot see how the internal opening would line up, if the venturis were installed the other way,...

[18Fiatsandcounting]

I cannot see how the internal opening would line up, if the venturis were installed the other way,...

This is my whole point. If the venturis are installed the wrong way, the openings won't line up and the only fuel you will ever get into the engine is from the idle circuit.

An important note: Geo and I are NOT talking about the venturis being upside down. We are talking about the possibility of the venturis possibly being installed a half-circle from the orientation they should be in.

Since we are unable to get a visual confirmation without removing the venturis, the only "diagnostic" that I can think of is to use carb cleaner to see if the openings are lined up and clear. You already have your emulsion tubes and air corrector jets removed. If you take some carb cleaner (with the red plastic pipe), you should be able to squirt some into the opening in the side of the emulsion tube well, where there should be a hole that points towards the auxiliary venturi. If you shoot some carb cleaner in that hole, it should spray out from the underside of the brass tube in the middle of the auxiliary venturi. If it doesn't, you've got a blockage somewhere.

-Bryan

[wetminkey]

Yeah, yeah, yeah,...turned around, not upside down - for God's sake then the opening in the venturi would be at the top. Don't you think I would notice THAT?!
I can see that the hole in the emulsion tube well lines up with the end of the brass tube in the venturi - it WOULD NOT, if the venturi was rotated 180,...
I cannot remove the damn things, anyway.
I'm getting TOO MUCH FUEL, dude. Not too little! Lost you somewhere, huh?
I'm done with advice here. I'll contact geo and dinghyguy by PM, as needed, and seek advice on mirafiori,...

[18Fiatsandcounting]

OK, I get it that my input is not helpful here, so I will bow out (for good this time). I wish you success in getting your spider running properly, and I am sorry that I couldn't be of more help.

-Bryan

[wetminkey]

Back to haunt y'all with the solution to this disabling problem,...
None of it was ever caused by the new DFEV carb (as was found on my complete tear-down), the PROBLEM was caused by a new catalytic converter, installed on an engine with a head-gasket coolant leak. The 20 miles home on the highway caused degradation in performance, and despite the head gasket fix afterward, every run of the engine made the constriction in the cat worse (burning the old crap out, I'm sure), until the engine would not start.
Unbolted the "4-2" cast iron manifold from the "2-1" header pipe, and the engine fired right up.
Not a situation familiar to me,...I'm kinda "old-school", and I don't have ANY other carbureted vehicles with a catalytic converter,...kinda a nutty idea!
But when all else fails, and left with NO OTHER POSSIBILITY, punt.
Glad to have this Spider BOTRA (Back On The Road Again). Runs better than it EVER has in the 20 years that I've owned it.

[geospider]

Well Todd. Glad you got this running. Knew you would like the carb conversion compared to the old.
now go have fun.

Geo