Carb Flooding

[C.Jett]

85 F150 SB Carb 4.9  How to install gauge to check fuel pressure? New fuel pump, supposed to be correct fuel pressure. EGR valve installed. Installed 2, 1/4” spacers between carb and EGR valve. Single gasket between carb and Intake. CJ

[ArdWrknTrk]

Just deadhead a Fuel pressure gauge at the carburetor connection and start the truck with the fuel left in the float bowl

[C.Jett]

Jim, you busted my bubble, I was going to reinvent the wheel with hoses and fittings. I just reached a milestone on Dec 24, 83 yrs OLD….. That’s my excuse and I’m sticking to it! So, do I have the gaskets correct? Thanks Jim. CJ

[ArdWrknTrk]

Happy Birthday CJ!
Congratulations, that IS quite a milestone

I will look closer at the gaskets. BRB....

[ArdWrknTrk]

Okay, here's an exploded view with the 9447 gaskets on either side of the EGR plate under the carb.

[C.Jett]

Thanks for the wishes Jim and the help. Does 9a589 represent spacer or EGR ? Doesn’t look like my EGR. So I don’t need the 2 1/4” gaskets at carb?  CJ

[ArdWrknTrk]

9a589 is a generic part# for the spacer under the carb. (these sketches are deliberately universal)
I can look for the specific part for your truck in a bit (I know Gary is busy)
But right now I'm collecting a wreck on the side of a highway.. 😄

[ArdWrknTrk]

This might take a while.🙄
I have to get her back over the guardrail...  🙃

[C.Jett]

Thanks Jim, good luck with the wreck. CJ

[ArdWrknTrk]

Sorry I got very busy and had truck trouble this morning.

Let me go dig up some specific numbers for your vehicle....

[Gary Lewis]

Yes, Gary has been busy.  But I'm home now and can look up part numbers.

So, is the question what the whole part number is for the spacer for this truck? Like the spacer is missing? Or, what am I missing?

If I remember correctly, there's a spacer that was used in Canada w/o EGR, and the spacer used in the US with EGR.  Am I looking for one of those?

[ArdWrknTrk]

I just wanted him to know the spacer IS an EGR (in the US) and the drawing is poor for a reason.

That there are two different gaskets. One above and one below. Not both stacked beneath the carb.

Can you handle this? I've got 1/2 hr to get in to work.

[Gary Lewis]

I've got it.  Be safe.

[Gary Lewis]

Yes, the spacer for trucks destined for the US was also the way that exhaust gas got into the intake.  But the spacer for Canadian trucks blocked the EGR passage.  And there was a gasket above and below that plate.

Let me see if I can find illustrations or pictures...

[Gary Lewis]

None of the instructions we have for rebuilding the YF/YFA show the spacer.  Nor do any of our emissions info that I can find.  And many of our posts about them have links to eBay, but those adverts have expired so there are no pictures there either.

But this thread on Non-EGR spacer for 300/4.9L [D7TZ-9A589-H] - NOS has the following two pics.  But be aware that this spacer is one of the non-EGR units so it actually blocks the passage in the intake and exhaust manifolds.  So your spacer will have some passages in it that this one doesn't, and you should use gaskets, one above and one below, that match the passages in your spacer.

[C.Jett]

Thanks Jim, Gary I bought a rebuilt carb and it would not work. They shipped me another one. About 50 miles later, it flooded over. Bought a Chinese carb, worked great fr about 4 months and flooded over. Removed and installed the 1/4” gasket (2) between carb and EGR. It just flooded over again. Installed a new NAPA fuel pump, it has 7 psi, w hitch is the max psi for this engine. Any ideas? CJ

[Gary Lewis]

From my experience two things can cause a carb to flood - too much fuel pressure and junk in the tank.  And "junk" includes gum or goo as well as rust or grit.

As for fuel pressure, I've run 460's with 5 psi, so a 300 six with a 1 bbl doesn't need more than that.  But I can't tell you the max that your Carter can take, although maybe Bill can.

So if you think your tank is clean or have a good paper filter ahead of the carb, then I'd install a fuel pressure regulator.  I've used this Holley unit on several vehicles with good success, but I've paired it with a gauge, like this one from AED.

[C.Jett]

Thanks Gary, I was leaning toward a regulator, I have new tanks, lines, pump and filters. I really hate to cut the steel fuel line. Do you have a better method on install? Thanks CJ.  PS Haynes says 4-7 psi.

[Gary Lewis]

I don't like cutting the steel line, either.  So I'd consider using a rubber hose from the pump to the carb and put both the regulator as well as a paper filter in there.

But you may have a problem finding a fitting that works in the pump.  That's a flared fitting in the pump and finding a flare to hose-barb fitting isn't easy.  If you can't find that you could use a flared fitting and a short piece of flared line.  If you are doing the flaring put a little bit of flare on the end going to the carb so the line can't slide off.

[ArdWrknTrk]

Well it seems you both have made progress.

I'd be tempted to buy a stock piece of brake line and find one of the 87944-58 nuts to slip over it