What model# fuel pump are you CIS guys using

[gbgastowers]

I was checking to see if I had the correct in-line fuel pump for my fairly newly acquired non running 82 Euro S (CIS). The one that's on it is a Bosch 0 580 464 045(flow rate 141 L/HR and operating pressure 400(KPA). The one that is supposed to be on it(according to PET and Bosch) is a 0 580 254 053 (fr=175 and op=500) or 0 580 254 967 (fr=168 and op=500). The one I have on it won't work will it? I think the pressure and flow rate would be too low. I don't think I have an in-tank pump due to the fact I see no wires coming out of the tank outlet.

[DPW928]

The CIS system needs the higher flow rate to maintain proper system pressure. Also, a lower flow rate can contribute to hot start problems. I would go with the proper pump specified in PET (only one will match your configuration) or a 6.5 bar Pierburg pump.

[MPDano]

The stock correct ones. CIS pump has that longer neck on it too. If you don't have the in-tank one then I bet you have another one in the rear fender somewhere.

[Fabio421]

Originally Posted by MPDano

The stock correct ones. CIS pump has that longer neck on it too. If you don't have the in-tank one then I bet you have another one in the rear fender somewhere.

No. The pump is mounted under the cover at the rear of the car that is located on the bottom of the fuel tank. There is no pump mounted in a fender somewhere.

Use the correct pump or the engine may "break up" under high load and RPM situations.

[Xlot]

Originally Posted by Fabio421

No. The pump is mounted under the cover at the rear of the car that is located on the bottom of the fuel tank. There is no pump mounted in a fender somewhere.

Use the correct pump or the engine may "break up" under high load and RPM situations.

Some CIS cars have more than one pump.

e.g. Dave's car: SharkSkin - Shark Attack Round Twenty - Fuel Tank Vent Line/Filter Refurb

[DPW928]

Porsche transitioned from a fender mounted pump to an under tank pump in 78. The early 928's that were manufactured for destination to hotter climates were equipped with a second in tank pump. The factory pumps did have the long neck which contained the internal check valve. The aftermarket Pierburg doesn't have the internal check valve but the 6.5 bar unit that I bought includes an external check valve and all of the required fittings.

[MPDano]

Originally Posted by Fabio421

No. The pump is mounted under the cover at the rear of the car that is located on the bottom of the fuel tank. There is no pump mounted in a fender somewhere.

Use the correct pump or the engine may "break up" under high load and RPM situations.

Uhm Fabio, he was talking about a 2nd pump. I know the main one under the tank next to the fuel filter. He either has the "2nd" fuel pump right at the fuel tank inlet (in-tank pump) or he has one in the rear fender. Mine is an in-tank and I am pretty sure if it's not an in-tank, there's a 2nd fuel pump in the rear fender (not sure whether left or right).

I could be wrong, but I thought all CIS had 2 pumps.

[american-kiwi]

My 78 with CIS , 5spd, has 2 pumps...one under the tank behind the black cover, the 2nd is in the pass' side rear wheel well right up by the tail-lights (not covered up)...you should be able to see it by just looking under there...i had to replace both pumps...if you start replacing that 2nd pump...you will be replacing fuel lines too....mine was as hard as rock...as soon as i tried to undo the in-line fuel lines they just fell apart on me...too dry rotted...i would say if there's no pump under the fender...someone has removed it and bypassed the lines to the filter/accumulator assembly ... CIS needs the 2 pumps to run right...(75-80 PSI) it will run on one pump...but give it some heavy gas and it will loose power (i know..lol)

PS...both pumps need the one-way check valves too