TheSamba.com :: View topic - Carter fuel pump/regulator combined good or bad?

Tue Aug 17, 2021 10:30 pm

no regulator
You can either adjust the fuel pressure to work with the carb, OR adjust the the carburetor to work with the fuel pressure.
As long as the fuel pressure is nice and constant, and it should be, then you'll probably be better off without a regulator.

On a weber IDF the float level is easy to adjust and the needle/seat size can be changed if needed, and different types are available. You might notice we don't have total agreement about what normal should be.
Some run the float level as high as 10mm, others drop it as low as 13 Lots of reasons why they sometimes need different setting, but the pressure is one of them.

If it produces 5psi, that's probably FINE, and will work, or you may up setting the float level a little different if needed. Just take it into account and tweak things the right direction and no problem.

Instead of running exactly 3psi because some big head decrees it so, then going up to a 2.0 needle and seat to FEED all that hp you will be making....well your working too hard.
smaller hole higher pressure VS big hole lower pressure....same result.

But if you had a set of kadrons then you better adjust the fuel system to whatever makes em work, ok sure, because.... well, if you've dealt with those you'll probably get it. the needle and seat is available in one size, one type, one quality(not great) and the float level is mysterious.
The weber IDF, no such issues. The float design is pretty darn good.
As I said some people have problems, I believe it, but there are a lot of reasons why and a lot of ways to fix it, so you can choose which one you like to do if you encounter any problem.
If you like regulators, I guess that's fine too, but of course there is always some loss through a regulator, so you end up needing a larger fuel pump to do that all else equal. More parts to break IMO
Some people like gauges, some don't.
That's another thing I like about these pumps is...you don't really need to check the pressure more than once...because, it's working perfect, or it's not working at all. At least 9 times out of ten.
I thought it was impossible for then to partly fail, but somebody said one did, somehow, so it could happen, tho very unlikely. Far more likely the gauge failed really.

Wed Aug 18, 2021 7:06 pm

Thanks for the feedback Modok! I felt the same about keeping it simpler with fewer parts/failure points and variables.

Thu Aug 19, 2021 9:29 am

https://www.rockauto.com/en/parts/carter,P60430,fuel+pump,6256

Here are both the carter fuel pumps. One has a 3/8" inlet and the other 5/16". Both indicate the flow of 15 GPH.

Thu Aug 19, 2021 10:43 am

74 Thing wrote: https://www.rockauto.com/en/parts/carter,P60430,fuel+pump,6256

Here are both the carter fuel pumps. One has a 3/8" inlet and the other 5/16". Both indicate the flow of 15 GPH.

I notice they do have a slightly different "Minimum Pressure". The P60430 is 2.0 and the P90091 is 1.0. They are rated at the same flow rate so I wonder if this has to do with the outlet being slightly smaller than the inlet on the P60430 causing the slightly higher pressure?

Thu Aug 19, 2021 2:43 pm

Since the published output pressures of these pumps seem to vary from vendor to vendor, (and the output pressure may very well vary from pump to pump), the way forward is to install the pump (either pump) and measure the output pressure for yourself with a quality gauge on a "T" fitting at the carburetor inlet.

That way, you can decide if a regulator is required based on the pump you have on your car, powered by your electrical system, pumping through your fuel lines, etc.

Good luck, Mondshine

Thu Aug 19, 2021 3:42 pm

mikedjames wrote: I took a Carter apart, or rather I was given one in pieces. There is a spring loaded ball valve forming a pressure regulator. It opens at 3.5psi or whatever and dumps the flow from the pump back to the input.
Would that ball valve be accessible enough to change on one of these pumps we didn't want to ruin? The idea that we could adjust the pressure to meet our needs would be nice.

[EDIT for vague wording]

Thu Aug 19, 2021 4:51 pm

The P60430

https://carterengineered.com/electric-fuel-pump-p60430

The P90091

https://carterengineered.com/electric-fuel-pump-p90091

Unfortunately Carter fails to provide max or minimum pressure (PSI) and flow (GPS) on the P90091....

So probably any specs published else where is pure BS...

Sent off e-mail to Carter for more information on P90091 about pressures and flow rates.... Waiting for (hopefully ) their response...

Fri Aug 20, 2021 6:24 am

Directly from Carter Carburetors Technical Services hot line...In response to my inquiry on missing data on P90091 fuel pump....

(screen shot of e-mail response)

Sun Aug 22, 2021 5:14 pm

Hi yall. Im gonna order the carter P90091 for my beetle, and was wondering if someone could please measure the OD of the pump body for me? I want to 3d print a custom base/mount for it and would like to have it ready for when i arrives.(plus im sick and need something to do :lol: )

also, is there any reason why i cant replace the fuel filter that comes with the pump? I have a nicer one i would like to use.

Thanks

Sun Aug 22, 2021 5:54 pm

Here's the measurements from my P90091.
pump diameter 1.6170
filter diameter 1.7065

Regards,
Jason

Sun Aug 22, 2021 6:28 pm

55rag wrote: Here's the measurements from my P90091.
pump diameter 1.6170
filter diameter 1.7065

Regards,
Jason

awesome thank you very much and God Bless!

Sun Sep 19, 2021 7:47 am

I am also in the market. I went with the P60430. It is ordered but not installed.
..,But what about the block off plate? should you block off? Should you leave it on just in case the electric pump dies so you have a spair?

Sun Sep 19, 2021 7:52 am

Either works although idk if you will burn up the mech pump by running it dry that long.

I ended up getting the p60430. Its way too much pressure for solex carbs. My car runs real rich cuz its just pushing fuel out the carb. You need a regulator.

Sun Sep 19, 2021 7:27 pm

All the fuel lines on my bus are 1/4"
neither of these are 1/4" If I reduce from 3/8 to 1/4 won't that boost pressure? that's not what I want.
I got a 60430 and now I think I should have got the 90091.
It doesn't look like either have 1/4 in or outlets. I might need to change out all the lines...?

Fri Dec 03, 2021 2:17 pm

I'll work on sharing the files tonight along with a hardware list, but here's the final product. Looks great y es muy robusto.

Fri Dec 03, 2021 2:33 pm

Just in case anybody needs this, I totally independently of this thread had the exact same questions a long time ago about an EFI lift pump application, but the two pumps I was considering were the exact same! Click on the pictures to be able to read them. I realize Mr. Dale M. already posted basically this same thing, this just adds what he thought was the horsepower support level and calls them "both internally regulated"

The typo in the response: he meant to say these might NOT be good choices
(turns out they were good choices because I have slow cars in a world where 1000HP is just a junkyard LS and one eBay turbo away.)

Fri Dec 03, 2021 2:46 pm

Now you see the Regulator and now you don't !!!!!!

Was using all types of electric fuel pumps and never a problem. Than. I read all the stories how electric pumps start to fail from over or under pumping,
so I buy a pressure regulator.

Big mistake. For a year or two all was fine then my car started to run like crap.

The Regulator failed. Removed the Regulator and the car was back to normal.

What does that tell me-- for two years I ran the regulator and it was totally unnecessary>

Fri Dec 03, 2021 9:26 pm

I purchased a Carter pump with filter for my DC a while back. Did a bit of searching afterwards to buy a spare inlet filter and could not find any specs for it , manufacturer part # or micron size. Has anyone found this info?, I think I read somewhere that 100 micron is acceptable for an inlet filter.

Sat Dec 04, 2021 9:00 am

100 micron on the inlet filter. You don't want the pump working extra hard, delivering fuel to the engine.
10 micron on the outlet side. I placed mine next to the trans.

I ran a Malpassi regulator in the engine compartment.
The cheaper the regulator, the sooner it is likely to fail. See Joe's comments above.

Sat Dec 04, 2021 10:44 am

I find it frustrating that none of the metal can off the shelf filters state what micron size they use, looked at Cater website, nothing there either.