Well, I drove it...

Filling brass floats sounds good in theory but I have yet to hear of ANYONE have any long term success.

If you can't find the correct nitrophyl float (are you SURE they don't make on for the YF?) then get a nitrophyl float of the nearest correct shape and join it to your old float arm
 
Linc's 200":24slr8in said:
Filling brass floats sounds good in theory but I have yet to hear of ANYONE have any long term success.

If you can't find the correct nitrophyl float (are you SURE they don't make on for the YF?) then get a nitrophyl float of the nearest correct shape and join it to your old float arm
Click to expand...

I haven't found one yet. I am about to take the top off the carb, and if the float is crunched, that is precisely what I will do.
 
Alright, so it wasnt collapsed...

But it was full of Gas. Sunken float - makes sense..

So I went and got the closest solid float I could find, and I hacked and cut and soldiered and now it's in there.

Problem is, I can't get it set for crap. To high and it overflows the carb, too low and it runs out of gas...

My fuel pressure is about 5-7 psi by my crappy gauge. What is odd is that this last time it overflowed the carb, I took the fuel line off and tried to blow up through it - and nothin, the needle was seated.

I am pretty confused. I just set it down again and it ran out of gas. I am going to try setting it up a little at a time...
 
Okay now I am just getting greatly peeved.

I drained the bowl, and rejiggerd the float to make sure it wasnt catching up on something.

I then bent the float down and set it in, checked the seat - open.

I added some fuel by hand until the bowl was half full - then dropped the top back on and checked the seat - closed.

Perfect, I think. I fire it up and it run for a second and then FUEL STARTS POURING OUT OF THE CARB.

What the heck?

So I check the seat, and its FREAKING CLOSED! How the hell is fuel pouring out of the carb when the SEAT IS CLOSED?

I hate freaking carburetors. I knew I switched my camaro to EFI for a reason....
 
Okay, here's the deal. The pressure is overcoming the needle @ approx 4 psi.

I think what's going on is that my new homebuilt float is less buoyant than the brass one I took out (duh). That means that the fuel can overcome the needle at a lower pressure.

So, the question is how do I solve it. I can lower the pressure to like 3 psi VIA a AFPR (which is lame) or I can try to make the thing a little more resilient.

I hate cars...
 
What's odd is that, upside down - the float holds up to 15 psi with it's own weight... So it's not like it takes a whole lot of force to keep the needle shut...
 
Only thing is, I've got a pile of stuff to go EFI here sometime soon - and I don't really want to drop the 100 $ on an aeromotive AFPR right now. I was hoping to get it running o-k on the mech pump.
 
Alright, so I cheaped out and bought a 27$ spectre AFPR from pep boys. I installed in and it seemed to help a LOT.

After screwing around for a little, I've got it set at the max (5.5) and the carb no longer overflows. I think I might be draining the bowl on acceleration 'cause by the time I get to 3rd and 4th gear it starts to fall on it's face.

I don't have any pressure reference right now. What I am thinking is that If I start out w/ a full bowl - I have enough fuel there to make it through like 3rd gear. Then It starts to go dry. Since I don't have a pressure reference, anytime I am making more than a few PSI of boost, The bowl is not filling because it is at higher pressure than the incoming fuel. It takes a finite amount of time to drain the bowl, which is why I only see the stumble after a few seconds on boost.

If I let out and get out of boost, and then go for it again - It pulls again. That would make sense if the bowl filled back up.

So, Either i've got to figure out how to boost reference this cheap AFPR I bought, or just deal with it. It's not a huge deal right now anyways 'cause it only happens if I go full throttle through the gears. Just normal driving it doesn't seem to be a problem.

Only remaining issue is that my wastegate doesnt seem to be opening. I will easily build as much as 10 psi w/ a 6 psi wastegate spring.

But, I can test that on the bench.

It pulls REALLY hard in 2nd gear haha
 
Woo-Woo.

Wastegate was opening @ like 11 psi. I cut the spring, but I did it too much - opens at like 3-4 PSI now.

But wow! Car is SO much faster than it ever was before.

Right now, I have the wastegate venting to atmosphere ('cause my 1.5" tubing hasn't shown up yet) and it is pretty loud when it opens up. I can't hear if there is any pinging because of it - altho with 3 psi I don't think that is likely to be a huge problem.

And my mech advance magically started working again - I have no idea why... but when I got the AFPR on and started getting it running right again, I went to measure timing and there it was, a solid 10*.

Weird...

I am still running out of gas when I dig into it, so I've got to figure out how to refernce this regulator, and i've got to shim the spring in my wastegate back up so I am getting 6-7 PSI... but I am so stoked with this car right now. It easily grabs rubber in 2nd gear.
 
niiiiiiiice!!! Isnt it amazing feelin when all of a sudden things start goin your way lol. I originally boost referenced the stock pump by drilling and tapping a hole in it and puttin a vaccuum nipple in...that lasted till bout 7-10psi and then it let a head gasket out...but it might help till u change ur setup. Now I have a mallory regulator thats boost referenced and it works like a charm!
Matt
 
Well, what I ended up doing was referencing the spectre regulator.

I took it apart and figured out how it worked. I then drilled a hole and epoxied in a 1/8" piece of tubing so I could apply boost to the spring side of the diaphragm. I'm not sure what the ratio is, but it should increase pressure with boost. Unfortunately I don't have a great way of testing this right now.

I referenced this to the carb hat so it only sees boost and not vacuum.

That seemed to help a little, but it really is hard to tell. The stock pump only puts out about 7 psi anyway so it can't get any higher than that. I have the regulator set @ 5 psi.

Before, I had heated and bent the arm on the pump in an attempt to lower the pressure. It may be that I need to take it out and straighten it since now I want to get as much pressure as I can out of it. I have an EFI tank w/ in tank high pressure fuel pump sitting here, but that requires a bypass regulator which is 130$.

What I need to figure out now is if my running out of gas on the top end is due to the pressure not being high enough, or something else. It's possible the YF's needle just can't flow enough fuel @ reasonable pressures to keep up.
 
I bought my aeromotive reg local for $95 new. nice thing is it comes with springs for carb and efi.

simpley going from a stock mech pump to an unknown GM intank and the reg made the car run smoother all across the board period!!

you can use the EFI pump and return style reg to with a carb spring to get it running on the carb and be sure to eliminate any fuel delivery issue.
 
I should mention that my attempt to mod the spectre regulator to be boost referenced was unsuccessful. As a result, I am currently in the do it again phase of "do it right or do it again."

I am clearly starving for fuel under boost. Car drives fine with carb hat detached. Pressure guage confirms no fuel pressure rise w/ application of pressure to reference port.

I must be draining the bowl. It makes it pretty hard to drive :)

The tank I have is for a '95 camaro. I've got it complete w/ pump, sender, and associated plumbing. I am planning on running a -6 line from the tank up to the regulator with a -4 return.

The tank should strap up under the bed pretty easily. I didn't want to take this project on yet, but here we go =/. There isnt going to be anything left untouched on this car once I take the fuel tank out.

It's fast when it has gas, tho. (and with only 3-4 psi!)
 
Ian,

I have the 13301 regulator, and I went with a 3/8" feed line and a 1/2" return. You do want a big enough return as they say.

In the begining I did the referenced mech fuel pump and it would not take 10 psi of boost (stock pump ran out at 5psi and the Carter at @ 8psi), reason for one of my blown headgaskets. Don't try and reference the pump and the regulator both at the same time either, they will cancel each other out. That's one reason I now have the electric Walbro inline pump, w/ regulator and no complaints so far. You do need your fuel pressure above your boost pressure if you want your fuel to flow correctly, but you knew that already.

Looking back at Linc's thread, maybe you are right about the YF needle not allowing enough fuel to flow thru it. Maybe drilling it's seat oversized a few thousands of an inch would help. I had done this to a stock carb on my bronco's 200 and it helped under heavier load conditions. Only suffered slightly under idle/part-throttle conditions due to the more fuel, rarely noticeable. At idle you could of course adjust the mixture screw in to lean it out.

Kirk
 
Well, The more I think about it, the more option #2 seems to make sense. Realistically, I won't be trying to go MPFI for at least a few months (lol) and I can justify a new regulator at that point. The 4-25 psi reg will allow me to run TBI in the next little bit here once I get bored with the carb.

I will mess w/ the needle/seat, but not until I get the fuel pressure sorted out. When my fuel pressure is lower than my boost pressure, no matter what I do to the needle its not going to work right :)
 
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