Re-jetting (or not) the DFEV

[wetminkey]

Other Webers have exchangeable venturis, but he DFEV is not one of them.
Since it is a brand new, Spanish-made Weber, it would be unlikely to have the auxiliary venturi installed backwards.
You have not followed the thread,...
Todd.

[SteinOnkel]

Other Webers have exchangeable venturis, but he DFEV is not one of them.
Since it is a brand new, Spanish-made Weber, it would be unlikely to have the auxiliary venturi installed backwards.
You have not followed the thread,...
Todd.

Todd,

Objection, your honor!

Last year my brother had the engine on his '74 914 (the spider-killer ) rebuilt. Bored and stroked, sharp cam, the works. Little thing has 2.3L of displacement now.

Anywho, he bought a set of brand spankin' new Redline Weber 44 IDFs. Guess what the venturi on one barrel was exactly backwards - so the fuel was dribbling out instead of spraying in. On a $1500 setup. From your friends in Gilroy. It took us weeks to figure that out and he was 2x more frustrated than you are.

I'll tell you what. If you like, I can put my currently-in-pieces 28ADF back together and mail it to you. That little friend will bolt right to your manifold. It's not complete - the emissions malarky is missing, but it ran well enough.

Cheers
Steiny

[18Fiatsandcounting]

Todd, maybe I'm beating a dead horse here, but if you really have a DFEV carb, you should have removable auxiliary venturis. Go back and look at the exploded diagram that you posted on the first page of this overall thread, and look at part #97. That is the part that I am talking about.

Also, I just finished rebuilding a 32/36 DFAV carb yesterday, and it's the exact same carb as the DFEV except the DFAV has a coolant-driven choke whereas the DFEV is electric. And it has removable auxiliary venturis that you can pull out with your fingers once the top cover is removed.

Note that I am NOT talking about the MAIN venturis, as those are indeed not removable or exchangeable on these models of Webers.

-Exasperated Bryan

[wetminkey]

Whatever.
Plugs are too fouled for the car to run beyond a single warmup cycle (to fan-on).
23 F for a high tomorrow, and nothing above freezing for the next week.
This thread has been of no help.
Time's run out. I'm done for the year,...
I'll pull the driver's seat and have it welded. Fight with the carb in the spring,...

[18Fiatsandcounting]

Understood Todd. I'll hold off on any advice for you until Spring 2020, or whenever you ask for input.

-Bryan

[wetminkey]

I'll fix it all by myself.

[wetminkey]

Or not,...
We finally had two days in a row with 65 degree weather, so I checked everything once more, and started the car.
Took some running around, adjusting the timing and carb, to get it to idle, but it settled to a nice idle and after a fan-cycle, or two, I tried to give it gas. Wrong,...it nearly died.
I let the car idle through four fan-cycles, since it has sat since last fall.
I have NEVER had a carburetor swap turn out SO poorly in my entire life! I just can't believe it.
I guess my only option is to blindly attempt to re-jet the DFEV and hope that is what the problem is,....
Anybody have any suggestions? Anyone KNOW how to go about re-jetting this carb? Redline Weber is useless,...I can't even get a consistent answer about float settings in the DFEV!

[18Fiatsandcounting]

In my last post on this thread, I offered to provide suggestions if you asked for help. It sounds like you are asking for help, so I am again willing to offer suggestions. Let me know how I can help.

-Bryan

[wetminkey]

I've been through everything so many times, it's getting stupid. Everything seems proper, but "this dog can't hunt!"!
New head gasket, belt + bearing, w/p, etc,...timing marks, rotor, valve position all proper when set,...compression test is good, new distributor with good adv.,...no leaks new single plane intake, DFEV float set 18mm w/ 2mm 'needle valve drop', speed screw @ 1.5 turns in beyond contact and A/F mix @ 2 turns out (per Redline Weber),...and 3psi fuel supply.
I advanced the timing enough to keep the car idling (pulley mark flashes at the engine cover 'crease', below TDC mark - engine idles without missing).
Engine idles fine, but has no power to rev, and bogs with slow acceleration - this is in Park,...the car barely goes anywhere in Drive - just in and out of the garage, on a level surface.
Car will not run with new air cleaner and positive crankcase ventilation attached,...engine dies.

I've never bolted a carb onto a car (or truck, or tractor) and had it run so poorly,...usually they'll at least go, and bog on acceleration, or something,...but I've never had a car not be driveable, until this Weber DFEV and single plane swap. The car has not been driveable for a year!
My usual strategy would be to return the car to the condition in which it ran well, last. BUT, that involves going back to the dual plane intake, and ADHA! And I swapped because I question the function of it's thermocouple system,...the car ran poorly after warmup.
So I'm perplexed as to how to proceed,...

[18Fiatsandcounting]

Yes, definitely frustrating! I haven't gone back through this whole thread, but from what I recall and with the info you just gave, it sure sounds to me like the engine is starved for fuel when you try to rev it. If it idles fine, especially if it does so happily for a minute or so, then you're definitely getting fuel to the carb.

One question and one request:
1. If you peer down the carb barrels with a flashlight when the engine is idling, do you see any fuel coming from anywhere in the barrel? You shouldn't, as the idle jet is right below the main butterfly at the bottom where you can't see it.
2. Can you take a picture of the top of the carb looking down into the barrels (choke wide open), and post that? The engine doesn't have to be running. I just want to see if something looks amiss down in each barrel.

-Bryan

[dinghyguy]

Hi Todd,

well we know you can at least make it look good if you wrap it in that nice red vinyl.....and since your car is so nice inside, by adding a TV who needs to actually move.....

adding the air cleaner and crankcase ventilation puzzles me, as if the car does not get enough air for the fuel it sees, but of course i am guessing.

Can you remind us all of what yoru various jetting numbers are, just in case someone else can point to something?
also if you look down the carb and move the accelerator can you see any fule being dumped in the barrels?
how far out is your timing at idle?

just a few thoughts.

dinghyguy cruising on sunday top down at 1degC

[18Fiatsandcounting]

dinghyguy cruising on sunday top down at 1degC

Good on you, Dinghyguy, but I once put my top down while cruising around in Yosemite National Park after an 8 inch snowfall, only to have the rear (plastic) window shatter as I put the top down. Must have been around -10 oC.

Back to matters at hand, and good idea about the accelerator jet/pump. Todd, let us know if you see fuel squirting from either jet when you work the throttle. The engine doesn't have to be running, and in fact it may be easier to see the fuel squirts if the engine isn't running.

-Bryan

[wetminkey]

Brand new DFEV, so nothing odd down either barrel. No fuel leakage during idle.

Gosh, Dan,...it's really nice to just sit in the car now, with the new, cushy seats. AAaahhhhh,....a TV would just be a distraction.
CCV oddness, and the desire to just stall, have me confused,...ought to want to run. And you've got to stop driving around, top-down, in the cold! You'll catch pneumonia,...or coronavirus!
Jets sizes are listed in the thread,...they are the ones that the stock DFEV comes with. I'll find, and list them again,...
Timing is probably where I would expect it to be for our altitude,...8 BTDC + 5 (1 degree/1000ft elevation) = 13 degrees BTDC, and I usually add a couple of degrees in for the low octane gas that we are forced to burn anymore. So probably 15 BTDC, total.

Weber accelerator pump question: I see fuel when I open the accel. linkage,...should I see a 'squirt' (like I'm used to), or what I observe, which is more like a short flow, or small gush? I see flow in the bottom of the primary bore, but not a squirt. Made me question it today,...
I need to run the engine again. Perhaps tomorrow,...supposed to be 65F.
Thanks for reading, and the thoughts,...

[18Fiatsandcounting]

Weber accelerator pump question: I see fuel when I open the accel. linkage,...should I see a 'squirt' (like I'm used to), or what I observe, which is more like a short flow, or small gush? I see flow in the bottom of the primary bore, but not a squirt. Made me question it today,...

Yes, when you open the throttle (either by hand at the carb or by having an assistant press on the gas pedal), you should see a squirt of fuel coming from the accelerator pump jet (and from nowhere else). When you stop moving the throttle, the squirt should immediately stop. If you see flow at the bottom of the primary bore, something is very wrong.

I realize that this is a brand new DFEV carb, but something is seriously wrong with how it is set up. I recall now that we've been through this before, but I would NOT assume that the carb was put together correctly when you received it.

It would be VERY helpful to see some pictures of what you have going on in the primary and secondary barrels (with engine off).

-Bryan

[dinghyguy]

There is a post on Mira right now about the same carb I think.....
Todd you might want to read it
Dan