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Ok To Use Two Fuel Pumps In Series?

  • Thread starter Thread starter Rangerang
  • Start date Start date Feb 9, 2016
R

Rangerang

New Member
Jan 31, 2013
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Feb 9, 2016
#1
  • Feb 9, 2016
  • #1
I have a 5.0 HO in a Ranger pickup. The engine has been hard to start which I determined was due to low fuel pressure. I jumpered the EEC-IV test connector to run the fuel pump constantly when the key is in "run" and that helped, I let the pump run about 3 seconds before starting and it works. I put in a new filter with no change. The in-tank 88 lph pump is fairly new and I use 93 octane non-ethanol gas so I'm puzzled that it's taking so long to build up pressure. I put in a fuel pressure gauge that shows good pressure when running, 38 psi at idle and about 45 psi at full throttle. So the in-tank pump works well except when starting. On a whim, I bought a 255 lph Walbro pump that I'd like to plumb after the in-tank pump and run both in series. Does anyone see a problem with running both pumps in series a) if they're both good or b) if the in-tank pump is failing, dies?
I considered that the filter sock on the in-tank pump may be clogged but it supplies good pressure at WOT and I thoroughly rinsed the tank when I replaced it. Ethanol gas had reduced the original pump to a lump of rust after sitting for six months. Also, fuel from the pump, before the filter, is pristine.
Please, please, don't suggest it's a regulator issue. I can barely fit a finger between the engine and the firewall, so accessing the regulator under the upper intake is a very major issue.

Another question, the Walbro pump draws 20 amps. I'm planning on using #14 stranded wire, sound good?
I have #14 on hand but can buy #12.
 

addermk2

5 Year Member
Aug 25, 2009
308
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Feb 9, 2016
#2
  • Feb 9, 2016
  • #2
replace the 88 with the 255 and stop over thinking things
 
Reactions: Adieu
R

Rangerang

New Member
Jan 31, 2013
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Feb 9, 2016
#3
  • Feb 9, 2016
  • #3
addermk2 said:
replace the 88 with the 255 and stop over thinking things
Click to expand...
I would, but I'm lazy. Removing the 88 requires taking the bed off the truck. And then I'm stuck with wondering what to replace it with. The 88 has a fairly custom twist cap that I'm not sure what to do about. Also, the 88 has the fuel level sender that I'd like to keep.
 

addermk2

5 Year Member
Aug 25, 2009
308
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Feb 10, 2016
#4
  • Feb 10, 2016
  • #4
So much facepalm...
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
8,914
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a van down by the river
Feb 10, 2016
#5
  • Feb 10, 2016
  • #5
drop in the 255 and call it good. That bed should be held on by what, 6 bolts?
 

addermk2

5 Year Member
Aug 25, 2009
308
87
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Feb 10, 2016
#6
  • Feb 10, 2016
  • #6
madspeed said:
drop in the 255 and call it good. That bed should be held on by what, 6 bolts?
Click to expand...

tanks come out the bottom too.
 
R

Rangerang

New Member
Jan 31, 2013
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Feb 10, 2016
#7
  • Feb 10, 2016
  • #7
Well, thanks for all the good advice but my original questions are unanswered. What would happen?
I'll assume no one knows.
Thanks.
 

Gearbanger 101

Straight Outta Locash
20+ Year Stangneter
Aug 10, 2002
9,457
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Ontario, Canada
Feb 10, 2016
#8
  • Feb 10, 2016
  • #8
What's with all the b****y new members lately?
 

addermk2

5 Year Member
Aug 25, 2009
308
87
49
Feb 10, 2016
#9
  • Feb 10, 2016
  • #9
Rangerang said:
Well, thanks for all the good advice but my original questions are unanswered. What would happen?
I'll assume no one knows.
Thanks.
Click to expand...
Oh no... we know what happens. We're just hoping you'll wise up and take the advise given to you by guys who have been doing this for multiple decades.
 

Adieu

Easy there, this ain't a dating site.
20+ Year Stangneter
Mar 7, 2002
9,531
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Feb 10, 2016
#10
  • Feb 10, 2016
  • #10
Ford used two pumps in sequence on the 80s Rangers and F-series. The one in the tank was high volume low pressure, and the one on the fuel rail was high pressure. What happened was, one pump would usually start to fail and take the other out due to the restriction it would cause. It was an overly complicated, un-necessary, and ultimately less-reliable system than a single-pump in the tank. That bull died with the last of the dual-tank trucks that were the last to use it. (And they were worse, three pumps, a selector valve, and a switch that all liked to fail.)
 
R

Rangerang

New Member
Jan 31, 2013
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Feb 10, 2016
#11
  • Feb 10, 2016
  • #11
Thanks. I'll see if I can gut the in-tank pump to save the fuel level sender. Also, the filter sock would still help.
I do have an '88 Ranger with the two-pump setup and have replaced both pumps a few years apart. But the truck has over 150k miles on it.
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,115
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Box behind Walmart
Feb 10, 2016
#12
  • Feb 10, 2016
  • #12
I just replaced the single Walbro pump in one of my vehicles. 230,000 miles.
 
R

Rangerang

New Member
Jan 31, 2013
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1
Feb 10, 2016
#13
  • Feb 10, 2016
  • #13
Impressive; Walbro is a great brand.
On my pumps, it occurred to me that I'd have a high-volume pump (255) sucking through a low-volume pump (88).
That's just a bad idea. So, never mind.
 

Noobz347

Stangnet Facilities Maint Tech... Er... Janitor
Admin Dude
Jan 4, 1985
43,115
21,288
234
Box behind Walmart
Feb 10, 2016
#14
  • Feb 10, 2016
  • #14
Yeah... Nobody really wants to create 'more' gremlins.
 

madspeed

Colonel Mustard
Founding Member
Nov 29, 1999
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a van down by the river
Feb 11, 2016
#15
  • Feb 11, 2016
  • #15
Egremlins are great until you add water, err in this gas gas
 
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