C4 fuel pump replacement options

Most of the fuel pump assemblies are for C2. C4 fuel pump assemblies need to have pickups for the venturi pumps. I'm doing PM and want to replace the pump in my C4. Where can you purchase C4 fuel pumps/assemblies without spending $$$ for P tax? It looks like the only real difference is the hose/pickup mumbo jumbo, not the pump itself. Can a replacement pump, Walbro etc, be installed in the housing and the housing from the old pump reused? Porsche 996 Fuel Pump Kit with Genuine Fuel Pump and URO Seal PEL FPKIT 996 996620103AX PEL.FPKIT.996 1J0919133A PELFPKIT996 | Pelican Parts 00 2000 Porsche 911 Fuel Pump - Fuel Delivery - APA/URO Parts, Autobest, Autopart Premium, Carter, Delphi, GMB, Genuine, Hella, In-Tank - PartsGeek

C2 version. Notice the price delta. 1999-2001 Porsche 911 Fuel Pump - APA/URO Parts W0133-5316576 - PartsGeek.com

Here are the fuel line shenanigans required for C4 variants. PS. You want to delete the black rubber piece.

Radium Engineering make an adapter to install aftermarket fuel pumps in the oem basket. Don't overdo the fuel flow or you will get unnecessary fuel recirculating which heats the fuel up.

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Well that's quite useful, thanks Prf. And conveniently, those guys are practically in my backyard. I'll be traveling through their neighborhood tomorrow afternoon. I may look them up. I think the turbo guys might do this more often; what's the pump they like and what flow would be NA 996 appropriate?

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A few companies make adapters for the 996. The one PRF linked is very nice and inexpensive. Mate it to a Walboro 342 for a 996 NA win win... Walboro is the gold standard for performance pumps and reliability... Or go for a URO and hope for the best, or pay big $$$$ for a Porsche pump. Actually, any of the above will probably work out for a very long time...

It's the wild west when you're searching for a walbro 342. Prices from $29 to $181, there's a whole industry of fakes. Buyer beware. 342 appears to be what turbo guys do if that's not too much flow? What's the solution for replacing that u-shaped piece of rubber hose that fails? I think recommendation is PTFE accordion fuel line for definitive repair. Might have to make a longer loop to prevent kinking. But too much might interfere with other lines.

I have removed the fuel pump, basket and sender to upgrade the fuel lines, specifically the horseshoe segment that splits and as a preemptive measure I am going to replace the 25 year old pump with the Walbro/ Automotive Industries unit using the Radium adapter. I will have a few questions. How can I tell if the check valve is functional before installing everything back on the tank? Is that necessary? Neither the pump nor the kit came with a sock. Are they generic enough to source at a FLAPS?

Looks pretty good for 26 years old. I cleaned it up a bit after this photo before opening up the tank. Pulling the pump wasn't too hard. I was able to spin the ribbed ring off by hand after a few tries.

If the car starts promptly after sitting overnight the check valve should be ok. I used submersible fuel line for that U hose. Do make certain it is submersible or you will be doing it again in a few days. I used an AEM 1200 fuel pump which is too much flow for a stock 420hp 996 Turbo. Seems about right for 580hp. Try to get a fuel pump with barbed connections. The AEM pump I used has connections without barbs and the hose has blown off several times. I used a filter sock from Radium, though they are fairly universal. You need one to fit the intake of your pump of course.

There are no obvious markings positive or negative on the Spade connectors. is that something you're supposed to know just by looking? Apparently the positive should be larger and the neg should be smaller. It looks like the one on the left is slightly thicker, not real impressive though. Seems like it would not be that hard for the manufacturer to indicate +/-. Which lead is positive?

And here are the fuel pump wires, Looks like black is positive, larger,, was connected to the positive terminal of the stock pump. Other wire is yellow, Goes to negative terminal on pump.

The 4 pin plug going to the lid: large brown is negative large other wire (black with stripe? Can't recall) positive Two small wires are tank gauge. Can't help you with fuel pump polarity.

Stock pump is clearly marked positive/ negative and positive is clearly larger. I guess that's too hard for the Walbro folks to indicate on their product. Or the one I got from a reputable seller is fake...

U r probably suppose to buy the harness too? Match up how the pic of this harness would go into the pump and it should give u the + side. https://www.tanksinc.com/index.cfm/p...0aAgDbEALw_wcB

Thanks, yeah I was looking at those. I ordered the harness pig tail just now so I won't have to try mounting female spades on the Walbro. The harness connector will help because the Walbro pump connections are very close together and the harness connector looks like it has a center bar to insure they stay separated. Do you have to assume the red pigtail lead is positive? Because that would mean splicing it to the corresponding black Porsche fuel pump positive wire instead of black to black. Red to black is probably right but it's pretty lame that the Walbro doesn't come marked and they have no online presence to document basic specifications. You don't want to have to do this twice. These pumps are common but it isn't clear which terminal is which.

I ordered a new sock too.

I got in touch with a walbro representative, they're under a different company name, Erickson or something. The walbro customer service number never got back to me. Anyway, The guy was very helpful, sounded like he was just a manufacturing worker but happy to check. he said pumps used to be marked and didn't realize that they were no longer including that. He did not know for sure. So he had to pull a pump and look at the specs. If you have the pump looking from the top, with contacts up the right hand connector is positive. Near the 1:00 position. The contact near the 11:00 position is negative. This is for the 255 pump. GSS whatever, whatever. I'll try to look it up. Interestingly, this does lead to a situation where you connect the black wire of the walbro pigtail to the car's yellow wire and the red wire to the car's black wire which is somewhat counterintuitive. Also interesting, apparently the contacts on some wallbros are reversed so best to confirm. Glad I did since I didn't want to drain the tank and pull the whole pump assembly again.

Has anyone here tried running the Radium 996 Turbo fuel pump kit in a Carrera 4S fuel pump housing, or knows if it fits/work properly? I�m looking for something a bit more capable than the factory setup and exploring alternatives for a track-focused car. Mainly trying to see if anyone has already adapted this kit or mounted a different pump/Walbro setup into the C4S basket successfully. Any info or experience would help.

I couldn't say. I did attempt to use the radium 996 fuel pump adapter but it wouldn't fit in my basket. Apparently it's turbo specific and my NA has a smaller aperture for the fuel pump that wouldn't accept the adapter. I don't believe they make one for a non-turbo. When I called them they said they had never had anything to do with the non turbos. The adapter is nice looking but it had to be returned and I am grateful that there was no trouble returning it. Summit was very prompt.

After running the new fuel pump all summer I can definitely say, not surprisingly, the previous pump was due for replacement and the GSS 255 has been doing great. It is smaller diameter than the housing for the stock pump so I had to fabricate a bit of a simple spacer around the pump to fit the basket. The turbo fuel pump must be different/ larger and have a different basket because the way it looked a turbo adapter would also require modification. I assume a c4s fuel pump basket would be the same as my C4 and any other normally aspirated 996 so the turbo adapter won't fit.

Here's what I used. Fuel Pump, Electric, In-Tank, 255 lph/67 gph, 80 psi, 12 V, 5/16 in. Inlet/Outlet, Hose Barb Fuel pump link Walbro Electric In-Tank Fuel Pumps GSS342BX