My facet mechanical to electric fuel pump conversion review.

[Clb]

@Thewespaul
Can you elaborate on this post???

Only thing that is post filter is the the rear most port which has the vacuum canister for the filter light.

You don’t want to restrict the return of the injection pump, worse case scenario it won’t even start, otherwise you will be limiting the amount of fluid cools the pump and injectors.

The valves can fail, but more than likely it’s a piece of old shower head that could be sucked up into the line. You can unhook your feed line and blow back to tank to be sure it’s clear of debris.

I was thinking of setting one at 5p.s.i. And putting it on the return to tank line AFTER the returns come together at the back of the block.
Still a nogo?

 

[Thewespaul]

You don’t want to restrict the return at all, max allowable return pressure is 5 psi. The reason you want to maintain the low return pressure is because of the affect housing pressure has on the operation of our pumps. The housing pressure affects fueling and timing and is calibrated for the low return pressure these trucks typically run. When you increase return pressure, you will loose fuel output and retard timing. Housing pressure acts as a hydraulic return spring for the transfer pressure side that feeds the plungers and acts on the cam to advance timing. When you increase housing pressure, you are effectively increasing the strength of that return spring which will decrease the amount the plungers can move out in their bores- decreasing fueling, and limits the amount the cam ring can move out to advance the timing. If you restrict it too much, you will either retard the timing too much and the truck won’t start or you will decrease fueling to the point that it won’t be able to pop the injectors when cranking. Less critical but still important, there will be less fuel flow passing out of the pump and injectors so you will loose some cooling and lubrication with a restriction in the return. You can see all this in action by pinching off the return of pump while the truck is running. The injection noise will slowly change then the truck will just shut off.

 

[Clb]

edit
jeezus I just lost 30 minutes of edit....
The rest is in Post 49 tap the quote box..

Ok I'm gunna cut this up into sections for clarification...
I am hoping to add to the search pool of knowledge, and help settle whats going on here(flashing fuel lamp).
We have some guru level stuff going on here
So please bear with me!

You don’t want to restrict the return at all, max allowable return pressure is 5 psi.
edit

ok if the e pump makes ?what 9 psi?
the running pressure 's reported are what?6-7 at idle?
How have you come to this"max return pressure being 5psi?
I am guessing the returns are unaffected, however you are talking about the timing and metering i side the pump,
?yes?

End edit

The reason you want to maintain the low return pressure is because of the affect housing pressure has on the operation of our pumps. The housing pressure affects fueling and timing and is calibrated for the low return pressure these trucks typically run.

This is what Mel talked about in the timing test psi vs advance!?
?yes?
End edit

Edit
When you increase return pressure, you will loose fuel output and retard timing. Housing pressure acts as a hydraulic return spring for the transfer pressure side that feeds the plungers and acts on the cam to advance timing. When you increase housing pressure, you are effectively increasing the strength of that return spring which will decrease the amount the plungers can move out in their bores- decreasing fueling, and limits the amount the cam ring can move out to advance the timing.

Edit
If we say in an unlimited supply (of flow\psi of fuel,) situation (the i.p can have all the fuel from the old mech. Pump) I am guessing at some point inside the i.p. ( after the metering housing ?) the feed Psi goes to the return side and the i.p. Has somehow relaxed...
So then how does the return side not run under pressure?

End edit

If you restrict it too much, you will either retard the timing too much and the truck won’t start or you will decrease fueling to the point that it won’t be able to pop the injectors when cranking. Less critical but still important, there will be less fuel flow passing out of the pump and injectors so you will loose some cooling and lubrication with a restriction in the return. You can see all this in action by pinching off the return of pump while the truck is running. The injection noise will slowly change then the truck will just shut off.

Edit,
This is the result of the feed pressures talk agnem did as to high feed psi advancing timing (internal) i.p. Just in the other direction? !
?yes?

@Agnem
@Thewespaul

 

[Clb]

Ok
So
I have no clue what's going on here(lost my long edit)
But tap the quote box from Wes' post quote, then you can see my lost edit session...

You don’t want to restrict the return at all, max allowable return pressure is 5 psi.

edit
The reason you want to maintain the low return pressure is because of the affect housing pressure has on the operation of our pumps. The housing pressure affects fueling and timing and is calibrated for the low return pressure these trucks typically run. When you increase return pressure, you will loose fuel output and retard timing. Housing pressure acts as a hydraulic return spring for the transfer pressure side that feeds the plungers and acts on the cam to advance timing. When you increase housing pressure, you are effectively increasing the strength of that return spring which will decrease the amount the plungers can move out in their bores- decreasing fueling, and limits the amount the cam ring can move out to advance the timing. If you restrict it too much, you will either retard the timing too much and the truck won’t start or you will decrease fueling to the point that it won’t be able to pop the injectors when cranking. Less critical but still important, there will be less fuel flow passing out of the pump and injectors so you will loose some cooling and lubrication with a restriction in the return. You can see all this in action by pinching off the return of pump while the truck is running. The injection noise will slowly change then the truck will just shut off.

 

[Thewespaul]

No worries, I’ll go through each one separately.

1) So you want about 5-6.5 psi inlet pressure fed to the pump because that is what the pump is calibrated with on the stand per stanadyne specs. The spec I used for max return pressure is what ford has in their manual. It’s under the section for trouble shooting continuous return cap leaks- the caps are only designed to hold less than 5 psi so they mark a restriction to the return lines as a possible cause for them leaking. They have instructions for putting a pressure gauge inline to make sure this is not an issue. It lists a restricted return to be the cause for poor performance, hard starts, smoke and engine miss.

2) yes just like that test with inlet pressure. Increasing Inlet pressure will increase transfer pressure, which advances timing, which is what Mel’s test shows. Restricting the return will back up pressure into the housing, which will act against that transfer pressure and keep it from advancing all the way.

3) the best way I can answer this is to give you a visual guide from an old stanadyne manual, I have a scan on my computer at the shop and I can send you a copy if you pm me an email.

4) exactly like Mel said in his test, just think of housing pressure as the return spring or a governor for that. With more housing pressure, you have a tighter spring holding back the transfer pressure which limited how much transfer pressure can actuate. Think of the relationship between housing and transfer pressure to be like a double acting hydraulic cylinder, but both sides are equal in surface area and movement is done by changing pressures on either side of the piston.

Clear as mud? I’m probably just confusing everyone more haha

 

[210Tumbleweed]

So...uh...if I'm understanding, to work around the factory IP design limitations:

Flow of lines (feed side and return) with restrictions factored in; must equal or exceed max flow of fuel pump, at any given rpm, at desired rate of delivery

(to match expected HP levels)​

. And then....some sorta...dual regulation of fuel pressures on the return and feed to accommodate fuel injector and IP optimal design parameter of 5-6.5 psi.

Or am I still missing somethin' or other?

 

[Clb]

Thanx wes,I'll work on it in the am..
Btw, I have a hard copy of the standyne manual that is posted in the tech section.

 

[Thewespaul]

The pump needs to have the feed and return pressure the same as it was calibrated at for it to work properly, I guess you could theoretically setup the pump with a 10 psi return pressure, but it wouldn’t be clear how that would affect the lifespan of the pump. My guess it would probably run into issues sooner due to it having less lubrication.

Clb, does yours have the color coated diagram that shows where the different pressures are divided up in the pump? It has a box underneath that explains what each pressure actuated on, this is what I was after to get a visual representation to make it easier to understand.

 

[MtnHaul]

Found this. Are the fuel specs in bold Ford's or Stanadyne's? And although this info is listed in regards to IDI Turbo engines would the same apply to N/A? I assume it would.

7.3L IDI Turbo Diesel Engine Performance Specifications
Engine Model A-185, A-166
Number of Cylinders 8
Configuration OHV V8
Bore 104.39 mm (4.11 inch)
Stroke 106.20 mm (4.18 inch)
Displacement 7.3 Liters (444 cu inch)
Crankshaft Rotation (Viewed from
Flywheel End of Engine) Counterclockwise
Compression Ratio 21.5:1
Firing Order 1-2-7-3-4-5-6-8
Idle Speed (No Load)* 650 rpm ± 50 rpm
Governor Speed (No Load) 3660 ± 50 rpm
Governor Speed (Full Load Rated) 3000 rpm
Timing (Dynamic) 8.5 ± 2 Degrees BTDC
Injection Pump Stanadyne DB-2
Injection Nozzle
Opening Pressure (New) 13,100 ± 517 kPa (1,900 ± 75 psi)
Opening Pressure (Minimum) 9,998 kPa (1,450 psi)
Crankcase Pressure-No Load (Maximum) 20 kPa (6 in-H2O) @ 3000 rpm
Fuel Pressure (Filter Inlet) 14 kPa (2 psi) @ idle
Fuel Pressure (Filter Outlet) 7 kPa (1 psi) @ 3000 rpm
Fuel Pump Suction 20 kPa (6 in. H2O) @ 3000 rpm
Fuel Return Line Pressure 14 kPa (2 psi) @ 3000 rpm
Valve Lifter 0
Valve Lash
Engine Lube Oil Pressure
Low Idle, Minimum 69 kPa (10 psi)
(Engine at Operating Temperature) 276-482 kPa (40-70 psi)
Crankcase Capacity (Without Filter) 8.5 L (9 qt.)
Crankcase Capacity (With Filter) 9.5 L (10 qt.)
Thermostat Opening Temperature 89°C (192°F)
* Manual transmission in NEUTRAL position. Automatic transmission in DRIVE position.

If the specs in bold are accurate then it seems there is tremendous pressure drop with the Facet pumps in the cases where the fuel filter light comes on. I started with the 40285 pump but the filter light would illuminate whenever I got close to WOT. I am curious how they test their pumps to determine the pressure ratings. It seems that the pressure range for a pump is with no plumbing installed after the outlet and that it is up to the purchaser to figure out how much restriction they are adding.

 

[nelstomlinson]

Here is what Pegasus says about the 40290:
This particular pump has a minimum dry lift capability of 50 inches. It can deliver up to 50 gallons per hour (free flow) or 12 - 15 psi (no flow). Typical application 20 GPH at 8 psi.

Why wouldn't we just use that with a pressure regulator which will cap its output at 5psi?

 

[Thewespaul]

A general rule of thumb, you need 1 gph for every 5 horsepower at the flywheel in a mechanical diesel..

 

[Clb]

Wes
I got sidetracked this am, running heater ducting in the shop....
Gunna read thru your last reply later on.

Fwiw
my standyne" automotive diesel troubleshooting guide literature # 99194"
was printed 11\89
And NO no color coded page.

 

[hce]

A general rule of thumb, you need about 5 gph for 1 horsepower at the flywheel in a mechanical diesel..

Is that correct or backwards, seems high?

 

[Thewespaul]

Is that correct or backwards, seems high?

Yep typed that backwards in a hurry, thanks Ill correct it

 

[Thewespaul]

Wes
I got sidetracked this am, running heater ducting in the shop....
Gunna read thru your last reply later on.

Fwiw
my standyne" automotive diesel troubleshooting guide literature # 99194"
was printed 11\89
And NO no color coded page.

That is a seperate manual, the one with the good stuff is the operation and instructions manual. Heres the picture I was referring to, this one is a dm2 pump but this manual is a bit newer and easier to read

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