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77 Seville fuel pump

Started by mechanic80, June 01, 2015, 06:10:34 PM

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mechanic80

I was curious as to whether there might be a single fuel pump "upgrade" for my Seville.  It should fit in the sending unit  in the fuel tank.  I can always hear the external pump working and it is a bit annoying.  Any info?
mechanic80

bcroe

Many people have complained about the noise; many of the original pumps have failed, and all
that stuff hanging in the dirt hitting the frame doesn't please me.  We need to find a high pressure
pump that will neatly transfer to the gas pickup tank unit.  They tend to be a bit too long. 

Some complete tank unit from a later car would be ideal, just drop it in, and put an in line fuel
filter only in the frame for downsized cars; the big cars already hang it on the engine.  Nobody
has done the research to find a drop in tank unit (yet); it would probably be for a port injected
car.  The throttle body injection cars use only about a third the pressure needed. 

My 79 Eldo is in the process of getting a total fuel pump and line makeover, including another
reconditioned (24 gallon diesel) tank.  The car needs to get to the close by GN this month, but
after that I may pursue this farther.  If someone finds a drop in tank unit I'll be testing it;
otherwise will try modifying mine. 

The fuel pump circuit on 70s EFI cars flows right thru the ECU, which quite often results in
a burned out ECU.  To avoid this failure, I have designed a circuit to reroute this power thru
an added relay OUTSIDE the ECU (just like all subsequent systems do).  The drawing is on
my PHOTOBUCKET first album, and I sell a kit with the 30A relay, socket with correct
color/gauge wires, and instructions for $10.  Bruce Roe

Gene Beaird

#2
Quote from: bcroe on June 01, 2015, 07:18:50 PM
<SNIP>

The fuel pump circuit on 70s EFI cars flows right thru the ECU, which quite often results in
a burned out ECU.  To avoid this failure, I have designed a circuit to reroute this power thru
an added relay OUTSIDE the ECU (just like all subsequent systems do).  The drawing is on
my PHOTOBUCKET first album, and I sell a kit with the 30A relay, socket with correct
color/gauge wires, and instructions for $10.  Bruce Roe

I have this kit, and highly-recommend it.  I actually think it quietened things up a bit back there, but not 100% sure.  The last time I started and ran our 79, I could barely hear the pump spin up at key-on, and was actually concerned that the pump(s) had died.  All concerns disappeared when the car fired right up! 

Thanks, Bruce!

IF the pump(s) ever give out, I'll definitely be looking for a pump that'll work to replace both.  I know a standard Walbro works on the 84-86 SVO, and the 84-85 SVO had the similar 'lift pump, main pump' configuration as the Seville, but it appears that Ford may have used a semi-standard-sized in-tank pump.  I'm pretty sure I pulled a replacement pump out of our 86 SVO, and can provide measurements of that pump, if anyone is interested.  I can even provide pictures, but it's a rust mess. 
Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

mechanic80

So what would be the recommended/needed PSI and GPH for such a pump?  It there a "too much" limit for a single pump?  I work in an auto parts store and have occasional spare time to  research such a pump.  I also have the original (functional) in-tank piece to use for comparison.
mechanic80

bcroe

Quote from: mechanic80So what would be the recommended/needed PSI and GPH for such a pump?  It there a "too much" limit for a single pump?  I work in an auto parts store and have occasional spare time to  research such a pump.  I also have the original (functional) in-tank piece to use for comparison. 

It sounds like you are volunteering to help all the 70s EFI car owners, that would be
appreciated.  I know I can build one system for myself, but better would be a solution
that anyone can easily duplicate.  There are pumps often chosen by the high performance
crowd (Walbro 255), but I think they tend to be way too large for this application.  There
are 160 and 190 LPH pumps, I may try a 190 on my 403. 

With port injection, you have the highest manifold absolute pressure at WOT, and the fuel
pressure tracks (above) the manifold pressure.  So you need max pressure when you need
fuel max volume.  The peak pressure is about 40 psi, the 76 500 engines need to support a
pump for maybe 400 hp.  The 350/425 systems could do with some 300 hp.  Bruce Roe

TMoore - NTCLC

-Someone would have to do some measuring, but I wonder how close the in-tank pump for the 94-96 Fleetwoods with the LT1 engine would come to fitting our application?  Very similar set-up (pressure regulator on rail) - I MIGHT have spares of both on the shelf to compare and see what could fit - will have to take look this weekend.  We could then take the chassis pump out of the equation - the original fuel filter could be used (although, opening that thing up can be a chore after a few years).

bcroe

Quote from: TMoore - NTCLC on June 05, 2015, 11:09:25 AM
-Someone would have to do some measuring, but I wonder how close the in-tank pump for the 94-96 Fleetwoods with the LT1 engine would come to fitting our application?  Very similar set-up (pressure regulator on rail) - I MIGHT have spares of both on the shelf to compare and see what could fit - will have to take look this weekend.  We could then take the chassis pump out of the equation - the original fuel filter could be used (although, opening that thing up can be a chore after a few years).   

That would be great, what pressure did the LT1 use?  Are there 3 lines?  From my own experience,
I'm in favor of ditching the 70s cartridge filter, and just use a common, simple, replaceable in line
filter.    Bruce

Gene Beaird

Bruce, they run at about 43# with the vacuum hose on the regulator disconnected. They run ~35-37# at idle. I believe I have an old take out OEM pump from a 95 Impala SS that I can measure, if anyone is interested.

A Walbro was a drop-in replacement, though.
Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

bcroe

That is just over the numbers in the book; haven't spent much time monitoring it myself. 
A solution with off-the-shelf parts would be so convenient and probably by far the most
economical.  thanks, Bruce Roe

Gene Beaird

Hopefully this helps some.  I got out to the shop and got some time to do some measuring.  Here we go:

1986 Mustang SVO fuel pump (actually a Walbro replacement of the OEM pump):
Pump diameter: 1.545" dia.
Pump length, body: 3.136"
Overal pump length (end-to-end): 4.70"
Pickup OD: 0.875"

1995 Impala SS fuel pump (OEM pump, will be standard size for any 1994-1996 B- and D-body car)
Pump diameter: 1.450" dia.
Diameter at rubber cover: 1.625" dia.
Pump body length: 3.775"
Overall length: 5.144"
Pickup OD: 0.745"

And here is a picture of the Impala Pump:



Both pumps run in te 35-45 PSI range. 
Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

bcroe

Quote from: Gene Beaird on June 07, 2015, 05:57:05 PM
Hopefully this helps some.  I got out to the shop and got some time to do some measuring.  Here we go:

1986 Mustang SVO fuel pump (actually a Walbro replacement of the OEM pump):
Pump diameter: 1.545" dia.
Pump length, body: 3.136"
Overal pump length (end-to-end): 4.70"
Pickup OD: 0.875"

1995 Impala SS fuel pump (OEM pump, will be standard size for any 1994-1996 B- and D-body car)
Pump diameter: 1.450" dia.
Diameter at rubber cover: 1.625" dia.
Pump body length: 3.775"
Overall length: 5.144"
Pickup OD: 0.745"

And here is a picture of the Impala Pump:



Both pumps run in te 35-45 PSI range.   

I know we can get a bare pump.  What I am looking for is a complete tank pickup unit
that can just be dropped into the gas tank without any fabrication.  We need to have
the right depth; guess a chart of that for all models would be good.  Bruce

Gene Beaird

The 94-96 B-body sender/pump mount has the three fuel lines leading out of the tank, but I have no clue if the diameter of the cover piece is the same as on a Seville/Eldo.  The lift pump on the Seville pick up is tiny, wow.  It looks like there's an extended hard line to the lift pump, that might be able to be removed/modified to work.  The other issue, of course, is the resistance in the fuel level sender, that could be an issue. 

Any idea how long (tall) the sender/lift pump assembly is, and what the diameter of the cover is? 
Gene Beaird,
1968 Calais
1979 Seville
Pearland, Texas
CLC Member No. 29873

bcroe

Substitute 70s EFI single pump High Pressure Tank Unit  8 June 15

Here are a few numbers to check for compatible tank units. 
Tubes dia & function
  3/8" pump fuel outlet
  1/4" fuel return to bottom of tank
  5/16" vent to top of tank. 

3.60" tank unit mount disc outer dia
3.22" tank unit mount disc O ring RIDGE outer dia
3.05" tank opening
0.235"  dia of O ring used between tank unit upper disc and tank. 

NEEDED are tank depths for
79-80 Eldo and 80 Seville
75-78 Eldo
76-79 Seville
75-79 big car

Bruce Roe

mechanic80

I do believe the problem is solved.  A  KESHEN 225  pump available on evil-bay for about 30 bucks replaces the in tank low pressure pump and eliminates the frame rail hi pressure pump. (also ethanol approved)  No noise, no faltering (seemingly caused by a weak in tank hose that leaked internally.) The one issue is finding the 5/8 (?) line connections to bypass the hi pressure pump. It's further back than the frame rail connection.  Be sure to use Fuel injection hose for this section!  The pump will have to be positioned on a slight angle to  allow the strainer to clear the inner sump of the tank.  Happy motoring!


mechanic80
mechanic80

bcroe

Quote from: mechanic80 on July 20, 2015, 02:21:48 PM
I do believe the problem is solved.  A  KESHEN 225  pump available on evil-bay for about 30 bucks replaces the in tank low pressure pump and eliminates the frame rail hi pressure pump. (also ethanol approved)  No noise, no faltering (seemingly caused by a weak in tank hose that leaked internally.) The one issue is finding the 5/8 (?) line connections to bypass the hi pressure pump. It's further back than the frame rail connection.  Be sure to use Fuel injection hose for this section!  The pump will have to be positioned on a slight angle to  allow the strainer to clear the inner sump of the tank.  Happy motoring!    mechanic80   

We appreciate your tests and input on this issue.  My own trial will be more involved,
when there is time to do it.  Changing to a TH425 trans in my 79 Eldo has put the
fuel line closer than I want to the left exhaust manifold.  So my plan is rerunning all
the lines up the right side, of course using something less corrosion prone.  I plan to
use a simple in line fuel filter, instead of that difficult and hazardous cartridge.  But
I have to figure out the fuel rails before starting. 

Still hoping someone will find an off-the-shelf, drop in tank unit that doesn't require
modification for a high pressure pump.  Bruce Roe

TMoore - NTCLC

any chance you have a link the Keshen 225 - nothing is coming up for me in a search

bcroe

I drove 100 miles to Milwaukee for the Olds meet today (with a Cadillac).  Coming back
I started about half empty working down to 3/4 empty.  The wide band OX sensor was
checking on the EFI mixture.  I got a look at what happens when the fuel pumps aren't
up to the job. 

At first I noticed the engine was gradually running more lean.  Then in any hard pull
it would go WAYYYY lean, till the gas stopped sloshing around in the tank.  With loss
of power, of course.  By 3/4 empty it was getting pretty bad, needed to get filled up
to get proper mixture again. 

I am still working a redesign of the fuel system layout & routing to suit my engine &
trans swap.  Once that is done, will try to get the new single pump setup installed. 
Meantime will have to keep the tank at least half full.      Bruce Roe