High pressure fuel pump for EFI Seville 78 350 gasoline

[ALAIN]

Hello,
I need to replace the high pressure pump on my Seville (1978 EFI 350 gasoline) but cannot find an original one at a reasonable price for shipping to Europe.

So I plan to use a PIERBURG 7.21287.53.0 but it shows some differences with original pump specs :
-   Pressure is 3 bars (43.5 psi) instead of 2,7 (39 psi) for the original.
-   Hose fitting diameter is higher (12 and 8 mm instead of 6 and 9 mm)
Anyone has a qualified opinion ? Experience ? Suggestion ?

Another issue is that I measure only 8 volts at the at the fuel pumps feeding cable.
Is this normal ? Will it be enough ?

Thank you for your help and advice
Alain

[bcroe]

I need to replace the high pressure pump on my Seville (1978 EFI 350 gasoline) but cannot find an original one at a reasonable price for shipping to Europe.
So I plan to use a PIERBURG 7.21287.53.0 but it shows some differences with original pump specs :
-   Pressure is 3 bars (43.5 psi) instead of 2,7 (39 psi) for the original.
-   Hose fitting diameter is higher (12 and 8 mm instead of 6 and 9 mm)
Anyone has a qualified opinion ? Experience ? Suggestion ?

Another issue is that I measure only 8 volts at the at the fuel pumps feeding cable. Is this normal ? Will it be enough ? Alain 

The pump needs to be rated higher than the highest
pressure the system will see, 39psi.  Then the fuel
pressure regulator will bring it down to what is needed,
might go as low as 29psi at high manifold vacuum. 
Needs enough volume to support 200hp.  I have been
using a Walbro 190 with good results.  Since I put it
into the tank, it is the only fuel pump in my 79 Eldo. 

The pump(s) need full voltage, better take a VOM
and find where you are loosing voltage.  The fuel
pump DC power circuit for those cars has been
problematic, yours may be on the way to burning
it out.  Check the very center pins of the ECU
connector, often BLUE  PIN C will burn out.  Other
issues are with the ECU relay and board traces. 

80 and later EFI used a pump relay external to the
ECU to avoid failure, I have designed a retrofit
for the 70s Cad EFI.  It will cure a burned pin
C problem, possibly fix your low voltage problem. 
Also check the condition of the in line fuse nearby
on the BLUE connector pin H wire. 

Other info, Bruce Roe  bcroe@juno.com CLC # 14630

[79 Eldorado]

Hi Alain,
I installed Bruce's external relay solution on my 1979 Eldorado. Bruce is able to diagnose and repair ECUs so he sees a lot of them. Here's a link to my install topic on the forum for installing the relay:
https://forums.cadillaclasalleclub.org/index.php?topic=153100.msg414525#msg414525

Let us know what you find.

Welcome to the forum,
Scott

[ALAIN]

Thank you so much Bruce and Scott !
I'll let you know the outcome and probably revert to you for more advices 
Have a nice day in America
Alain