Re-jetting (or not) the DFEV

[wetminkey]

Nice in-line fuel pressure gauge! And it tells me that this Weber will do much better with more than 1.5 psi,...I recall the specific drive that killed the old e-pump, too. Even pinching the return didn't do much to increase the supply pressure. Anyway, I bought a rotary Facet today, and it should be here soon.
Redline provided me with a corrected, proper float measurement for the DFEV, so I'll recheck that, and wait to install the new pump. It will then be time to check idle and function under load again. I'll re-jet for altitude as necessary, afterward.
Much more to come,...
Todd.

[wetminkey]

Back from a short period off, and I'm starting with easier projects at first. So I've done fluids/tune on my '68 Mustang, and some minor projects on my RX-7. Time to get back to the Spider's fuel pump and brake bleeding,...
I now have a lovely Facet rotary pump for my Spider, BUT it requires a filter on the input side, Facet #479735. I'll have one Thursday. It's a bit larger than the 20 year old 'cube' pump that I'm replacing,...I hope that I can install it easily! At least I've got 12V+ to the installation point,...!
Wish I was younger,...this is gonna hurt later.
Second time around for brake bleeding with new calipers. Seems like a solid pedal again, after re-bleeding the rears,...but that's what I thought before. Ah, persistence,...my wife and I will bleed the fronts tomorrow.

[wetminkey]

Brake pedal seems to be firm now, after re-bleeding the brake system. Yay!
The old Purolator e-fuel pump assembly was about 4.5" in length,...the Facet, with it's inflow filter installed, is about 7" in length! I was able to swap outlet fittings to my old, slightly shorter, brass fitting,...that gives me enough room for the outflow from the new pump. The provided barbed fittings are quite long! Just the inlet filter adds a lot of length,...
I checked it this evening, and it looks like everything will fit just fine, and even the bolt holes will line up! How friggin' lucky is THAT!??
I'll even have a 3.15A fuse inline this time,...in the trunk.
I couldn't finish up tonight, but I've got everything ready for the install in the morning,...
I've got one convertible finished for the year, I'd sure like to get this one running well before snow!

[markw]

It sounds like you're using a return line system? Are you sure that the feed and return lines are connected to the correct ports on the carb and not reversed?
I have fallen foul of this one before and have just had a look at a friend's car where the same mistake had inadvertently been made. It exhibited exactly the same symptoms. I think they're marked with arrows on genuine Italian made carbs.

Good luck

Mark

[wetminkey]

Ran fine for twenty years with the lines and pump hooked up this way, Mark. Same routing as stock,...
BTW,...easy to NOT screw up. BIG line is feed,...LITTLE line is return,...
No problems there.

[markw]

But haven't you just changed the carb? Feed and return line connections will have been changed too surely?

[wetminkey]

If you check back in the thread, you'll find that the WIX filter routes the return and feeds the carb. Impossible to swap the lines,...supply is 5/16" and return is 1/4".

[geospider]

With the 32/36, the return line comes off the fuel filter
using one of these. Very simple set up.
https://autoricambi.us/collections/filt ... eturn-line

[wetminkey]

Yup. WIX is nearly identical. Return feed comes off the end, though, instead of the side.
None the less, the car will start now, but not run. Sure acts like it runs out of gas NOW! Bogs after a few seconds, and dies. Ran better with my 20 year old Purolator,...
My fuel pressure gauge reads about 1.5 psi,...the new rotary is SUPPOSED to put out 2.5 to 4 psi. I question it's use on a stock return feed line,...I'll see what MB has to say about it.
I don't think anyone sells any parts of real quality anymore,...I've never seen so many parts, for so many makes of vehicles, that are just crap, than I have in the past 10 years, or so. Nothing does what anyone says it will, and half of the parts are defective.
I'm getting REALLY tired of trying to turn wrenches, anymore,...! Thanks for reading my rant. This kind of crap is the reason my simple thread about rejetting has become a HUGE thread about the whole fuel system!
Perhaps the car is cursed!

[wetminkey]

Finally got it running,...just as crappy as before, so my 20 year old Purolator 'cube' pump was doing the job just fine! No need for a new fuel pump,...
Direct feed to the Weber only reads about 2 psi ('average' with the flutter), so I'll assume that the new gauge reads low and that the Facet pump is good.
DFEV needs rejetting, OBVIOUSLY. Engine starts, idles and revs to about 1500, and bogs beyond that. Smells like too much gas.
The DFEV must have a 1000 gallon accelerator pump!! I've never seen SO MUCH gas come out of the primary jet with so little accelerator effort! Carbs of the 650 - 700 cfm size dump that much gas! Ask me how I know,...!
This has taken so long that now I'm stuck with trying to rejet in colder temperatures,...bad news.
I'm not so impressed with Redline Weber. I've NEVER bought a new carb that would not run well at this altitude,...they are also hard to contact, borderline helpful.
Hope I can fix this,...wasted a whole spring/summer/fall farting around with this DFEV. I should have reinstalled my rebuilt ADHA, like I was going to do in the first place.

[SteinOnkel]

Cheer up, buddy! We'll figure it out

Yes, Redline Weber are a shitty company to deal with. Their products have been consistently horrible. We had a set of 44IDFs from them brand new that came assembled wrong and were full of crap. Nice. They're return policy was "the finger" so that was double nice. Ended up tearing apart brand new carbs and getting them ultrasonic cleaned. Always a pleasure dealing with medium-sized companies. When will these guys realize that thanks to the internet we can buy this crap anywhere? I digress...

Couple of questions I have.

When you say accelerator pump are you sure the fuel is coming from the primary jet? My understanding is it should be a little tube in the primary venturi that has a shot of gasoline squirting out when you gas it. At 1500 rpm your primary should not be doing much of anything really. Perhaps you are idling on the main circuit?

Here's what I would try in regards to your fuel system. Idle the car for 2-3 minutes. Then kill it and remove the top of the carb. Look inside the float bowl, how much fuel is in there? If the well is full enough to cover the jets in there you are good. These carbs really don't care that much if they see 2 or 3 psi.

[18Fiatsandcounting]

Todd, in addition to Steiny's thoughts, I keep getting the impression that you're getting way too much fuel going through this carb and into the engine. Several possibilities: 1) float needle valve isn't working, 2) float adjusted so the gas in the bowl is way too high, 3) main jets way oversized for this engine.

I can't remember if you did this, but try putting really small main jets in both the primary and secondary. 110 or 115 or 120 if you have them. And see how deep your fuel is when you pull off the carb top. If it's over about halfway, probably too much.

-Bryan

[wetminkey]

Thanks for the encouragement, gentlemen. Much appreciated.
I've set the float a couple of times (since I keep finding various measurement methods), but I'll check it statically, as you suggest. That way I'll know for sure that the carb is getting enough fuel for demand, and not too much.
Having bought many carbs without having to alter ANY of them, I'm just a tad apprehensive about changing this Weber, but I have the baseline jet sizes recorded, so I guess that I can always change back, if I have to.
I stated my high altitude rejetting objectives a page, or two, back. I'll try to get the jetting closer to the old ADHA's jetting, since it's secondary is the same size as the DFEV's primary. I hope I'm reasoning that properly,...32mm is 32mm no matter what carb. Jetting should be similar.
Anyway, I'm following rejetting for altitude research that I've done online (also posted a page, or two, ago).
Sure wish I could have driven this car farther than to the end of the driveway this year. Got a lot done, but still going nowhere.
Manyana.

[SteinOnkel]

Yep, I hear ya. This is probably not the best to mention that my $150 34ADF Knockoff from Far East ran great out of the box

You could put your other carb back on and see what it does then. That would rule out a lot of things like valve lash, ignition, fuel delivery etc.

[manoa matt]

In case it was stated else ware, and I missed it. What coil are you using, and have you checked the primary and secondary resistance against the values listed in the manual? Primary should be 0.7000 ohms Secondary should be between 10,000 and 11,000 ohms The finned aluminum coil bracket grounds to the body, so the mating surfaces to the studs should be clean also. Other things to check are the ignition module mounted behind the coil to the coil bracket. Also there is a magnet in the distributor sandwiched between the magnetic pickup and the advance plate. There is a white painted stripe on one side of the magnet, IIRC the strip should face down when installing.