Today I .......

[mechanic80]

Replaced both fuel pumps on my '77 Seville and added the relay to the circuit to take the load off the processor.  The courtesy lamp repair is still holding and I still have the steering damper and front sway bar end links to install.  On the matter of the pumps, the external pump was noisy before its replacement.  Now barely a hum, but the in-tank unit is making more noise than before.  Can't be heard from inside the car but stand by the trunk and it's really noticeable.  Any thoughts are appreciated.  I'm getting good at removing that darn tank by now.

[76eldo]

Might be quieter with fuel in the tank?

Brian

[Gene Beaird]

Norbert, what relay did you use?   Brand, P/N?  Thanks.

[mechanic80]

Relay used was a Bosch 30/40 amp 5 pin.  Center pin was not used.  Mounted at front of left rear tire well.  I'll be housing it in a plastic box for weather proofing soon as I find the appropriate size container.

[Michael Brittan CLC #2750]

Norbert, what brand in-tank and rail pumps did you use, and where did you get them?
Mike

[bcroe]

Keep putting in those relays.  I saw 2 70s ECUs for repair this week, with a burned
fuel pump power pin.  But the relay fix (as shown on my PHOTOBUCKET) solves
the problem even if the pin is gone. 

The 2 wires to the NO relay contact should be heavier, 14 gauge works.  Some
of the plugs available use lighter gauge.  No problem for the relay coil wires. 
Bruce Roe

[Driver8]

Nice work on replacing those pumps. Mine have been changed once on the '79 and are still OK, but I did notice looking underneath this year that all the flexible fuel line sections in-between the rigid fuel lines need to be replaced along with new clamps. I will be sure to do this before another driving season. Did you happen to notice this on your '77 or maybe already addressed it? If you have replaced any line, what did you use? I was looking to use a reinforced FI line from JEGS.

I also recently completed Bruce Roe's external fuel pump relay mod. It gives great peace of mind to have that risk taken off the ECU. I also have a steering damper and F & R sway bar link kits sitting in the box waiting to be installed, but haven't gotten to them yet

Mark~

[mechanic80]

Replaced the rubber lines, all of them, as their age was apparent.  It's more expensive, but use premium (like goodyear gator) lines.  The ethanol in fuel is MURDER on simple rubber lines.  The steel lines all looked fine.

[Driver8]

Hi Norbert,

Do you remember where you bought the Gator hose, couldn't find it? How does this one look to you? >>  http://www.goodyearep.com/ProductsDetail.aspx?id=5144

What was the correct size you used on the under-body sections for gen1 Seville?  My rigid metal lines are good, as the car has 37K and was garaged all it's life.

Much appreciated. Mark~

[Michael Brittan CLC #2750]

Hi Norbert, Mark:

Can you tell me what brand pumps you used and where you bought them?  I recently replaced the rail pump on my '78 Seville with an Airtex, but it is as noisy as the pump that was taken out.  The pump is insulated from the frame rail, so I don't know what else to do to quiet the thing down other than trying a different brand.

Also took the opportunity to have the bypass relay installed as per Bruce Roe's excellent suggestion.

Thanks,
Mike

[Gene Beaird]

I think several have noted that when the external pump is noisy, it's usually a sign the in-tank lift-pump is not working properly.  Replace that pump, and things get a lot quieter, although insulating the external pump from the frame with some rubber padding can help.

[Michael Brittan CLC #2750]

Hi Gene:  The in-tank pump was replaced not that long ago, but maybe does not generate the required pressure.  If I could get recommendations for replacements of both pumps I would check them out against what is currently installed.  I use ethanol-free gas for the most part.  Mike.

[Driver8]

Mike, I am still looking for you. I do know they were from rock auto, but they had several. I will go in the records and get you the brands and post here or PM you. Mark