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returnless to Return style fuel conversion

I would replace the vacuum style one on the rail with an adjustable one and bam can't get anymore pressure past what you set it at
@Dee rockafella
If returnless, that won't work, because a pressure regulator can't simply lower pressure to a setting, it must dump the excess somewhere to regulate the pressure; with return type, it dumps excess into the return line.

Think of your garden hose. Has a fixed pressure at the supply pipe, you connect two hoses to it, one slightly open at nozzle, other very wide open. Add those two nozzle flows together, and you get how much the spigot is delivering. Same thing with fuel pump pushing fuel to the first nozzle (engine), the rest goes to the other nozzle (tank). imp
 



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That makes no sense. What are you talking about? On our 2nd gen's that are returnless style there is no regulator in the engine bay. Are you talking about the fuel pulse leveling out diaphram in one of the factory rails?

Also, for your info, you can't just restrict fuel. It needs to go somewhere. A return fuel line in needed.
@Dono
You're right! Fluid flow is a much-misunderstood thing, yet is so important to be able to work with effectively (meaning fix it or can't!).
 












In 1999 Ford changed everything to non-return fuel systems.
@CDW6212R

Thank you, Jesus! And, '99 was still Gen II. So my '96 had return type, my '99 did not, both 4.0, both OHV. A change that significant in mid-Gen throws many ringers......imp
 






Yea Imp, I really never counted on running in to this issue. It's a surprise, but the only way I can see to get the tuning portion right is to go back to return style. Tough to call it an upgrade when the factory did away with it a year or two before.

I keep telling myself I gain a high end adjustable regulator and the boost port to automatically up fuel pressure under boost.
 






Yea Imp, I really never counted on running in to this issue. It's a surprise, but the only way I can see to get the tuning portion right is to go back to return style. Tough to call it an upgrade when the factory did away with it a year or two before.

I keep telling myself I gain a high end adjustable regulator and the boost port to automatically up fuel pressure under boost.

That is true, and it makes me wonder how the later systems are more advanced at controlling fuel. I've read enough of how the newer PCM's are faster and easier to tune radical/boosted combinations. I haven't dug deep enough to find out if that's preference by tuners or idiots, or actually advantages of the later models. Can a later PCM operate a return style fuel system or does it have to be return-less. Interesting ....
 






That is true, and it makes me wonder how the later systems are more advanced at controlling fuel. I've read enough of how the newer PCM's are faster and easier to tune radical/boosted combinations. I haven't dug deep enough to find out if that's preference by tuners or idiots, or actually advantages of the later models. Can a later PCM operate a return style fuel system or does it have to be return-less. Interesting ....
@CDW6212R
I see no reason why a later model PCM could not run with a return type system, so long as the proper pressure were maintained at the rail. Early return-type used a simple vacuum-operated pressure regulator with a diaphragm which operated a valve opening into the return line. The pressure side of the valve was exposed directly to fuel pressure in the rail. As vacuum rose higher, meaning the engine was working under less load, less power called for, less gasoline needed, the diaphragm opened the valve farther, dumped more fuel into the return, thus holding pressure in the rail fairly constant under all engine demand conditions. How constant? Not very, as anyone who has watched a pressure gauge hung on the Schrader, might go up and down from 30 to 45 psi. That caused big variation in air/fuel ratio, harder to control, the difference being "covered" in closed-loop by the O2 sensors. EEC-IV (OBD-I) did this, running at around a 40 psi baseline, worked fine, as far as I was concerned. I used that system to power 8 or 10 conversions, a Maverick, 1/2 ton Toyota, 68 Mustang 351W, '70 Bronco, '79 Ranchero, even took a '71 F-150 with 390 and bored and mounted injectors on a home-made fuel rail set on injectors mounted in the ports of the cast iron manifold. It's crazy what you can do, if yer crazy!

This late '90s returnless scheme I knew nothing about, not even it's existence, until several really sharp guys here straightened me out......Then I bought a 2004 Ex, 4.0 SOHC, and learned Ford had added the pump speed control idea, maybe early in Gen III. I know they had a "fuel pump Module" before '04, which took the FPTS data and converted it into a varying voltage controlling pump speed by a feedback system: if rail pressure is constant, pump runs at a constant speed. Rail pressure drops a teeny bit (how much, I don't know, but probably several psi), or rises, as engine demand changes, the pump speed is changed to bring the pressure back to desired level. Slowed down for a short time, speeded up for a short time. How often? Dunno. But do know varying speed of DC motors every few seconds shortens motor life.

So why the hell go to the trouble? Asking for more places for things to f$ck up. True. BUT, mine has 165K on the original pump Ford put in the tank! Can't hear it run, yet. Longer pump life because the pump doesn't push maximum output all the time, as returnless did.

What else? PCM now has more control over programmability: added road-expected strategies can be used for varying F/A ratios for a variety of conditions not possible before. That don't impress me much.........imp
 












I'm doing a swap into my 2007 ranger and just goin to run a return back to the filler neck and use the pump and sending unit from the explorer so to keep it simple I'm pulling the motor and reringing it and new bearings and all and then going to put it in the ranger it's a drop in affair and change out some wiring and we are ready 3011lbs ranger will definitely move over an explorer though the explorers rear suspension setup looks at bit more like a mustang setup to make it hook where's the ranger I got to do something different
 






I bet Ford went to returnless to save on 10 feet of fuel line.

Some butt kissing egineer monkey was viewing some execs kidneys via his rear end, and figured how to pay for his summer home. lol
"The more you know" lol
 






I bet Ford went to returnless to save on 10 feet of fuel line.

Some butt kissing egineer monkey was viewing some execs kidneys via his rear end, and figured how to pay for his summer home. lol
@gmanpaint
They certainly didn't do so to help the fuel pump sellers. I want to believe you are being facetious. 10 feet of fuel line vs. added electronics, a sophisticated pressure/temperature sensor, less Dealer ability to understand.........not sayin' I really like it. What I REALLY would like to know, but never will, is who makes such ultimately important engineering decisions at top-level management, what are their qualifications to do so?

For example, to digress if you don't mind, the Buick Skylark years back introduced an aluminum block running piston rings directly on the aluminum, no sleeve. Dismal failure. Nothing learned, the damned fools introduced a BRAND NEW car line, the VEGA, same engine concept, failed again! Management blamed suppliers of aluminum for the blocks, which supposedly had exposed crystals of Silicon in the cylinder walls, upon which the rings "rode over", as improperly made material (??) Idiots! A FOOL can see sharp-edged iron piston rings will SCRAPE AWAY at soft aluminum cylinder walls.

More. The Cadillac "8-6-4".

"The V-8-6-4 system was designed to shut off either two or four cylinders to increase fuel mileage; this was determined by Cadillac's on-board Computer Command Module, which used sensors to monitor engine speed, EGR, idle speed, intake manifold air pressure, coolant temp, air pump operation and exhaust, and adjusted the air-fuel mixture accordingly. If the computer sensed a sustained cruise, a microprocessor (said to be capable of 300,000 decisions per second) would then signal a solenoid-activated blocker plate that physically moved the rocker arm, preventing the camshaft from opening the valve. Your six-liter V-8 would become a 4.5-liter V-6 or a three-liter V-4 at cruise, and a digital "MPG Sentinel" gauge on the dash would reveal how many cylinders were in operation. With only four cylinders doing the work, intake-manifold vacuum and pumping losses are both decreased. Fuel economy gains of 15 percent or more were realized when (or should we say, if) it worked.

That "if" is a biggie. Disaster doesn't quite cover the scope of what happened. Throttle-body injection issues paled in comparison to the valve switchgear: While the bottom end of the engine remained strong, the software needed to run the system wasn't nearly fast or powerful enough to manage the job at hand. Also, while press reports mentioned smooth transitions between four, six and eight-cylinder modes, buyers reported noticeable hesitations while the computer and hardware got their act together. To a Cadillac owner, this was an unacceptable driveability concern. Most V-8-6-4s saw the cylinder deactivation deactivated, leaving them in V-8 mode.

A year after Cadillac's failure, Mitsubishi introduced MD (Modulated Displacement) technology on the home-market 4G12 1.4-liter four. It disappeared quickly"


All of them made mistakes. Ford built the Edsel. Great car, but folks didn't like it. But compared to the other two of the "big three", I believe Ford made the least mistakes. Chrysler: Pacer. And others. But why is GM even still in business? "Brand loyalty", the most stupid and ridiculous reason to buy a product, and govt. subsidy.

I still like Ford's approach, disagree with a lot of their decisions, but WTH, everybody's human.
imp
 












Was just trying to bring some levity to the thread, with some comical relief is all. :D
@gmanpaint
Ah, relieved to hear that, though I suspected as much. Running and watching over a forum must be sometimes a PITA, I would guess! We like your style! imp
 












Oh Mr Imp..... you crack me up sir.

I'm not running anything around here, merely an observer, with the occasional referee whistle.
@gmanpaint
Jeez, again! First time in my life anyone called me that 3-letter word; it's always been "F*cking Engineer", usually spoken by a skilled-trades guy, welder, machinist, electrician, Millwright, who didn't know yet.........

imp
 






Figured I might as well update this as I go. Today was a warm day (The only warm one we will get for a few weeks) so I figured it might not be too bad on the floor of the garage by the garage door. I was right, it was ok. It didn't do without the standard swearing though, so at least the garage door was closed and the neighbours kids weren't around.
I took the tank to a car wand wash and cleaned it up so replacing the tank should be easier (Less crap falling in my eye's).

fuel pumps side by side.jpg

Return style assembly on the left
Fuel pumps side by side 2.jpg

The bottom assembly is the returnless style assembly, notice the fuel regulator. Also notice how dirty the filter sock is on the right of the returnless assembly I pulled out of my tank.
Tank ready to go in.jpg

Cleaned up and waiting for me to lift it back in place. I did take the tank to the street and swish around the little bit of gas left and dump it out by flipping the tank upside down. Hopefully that took care of some of the black crud that was on the pump sock.
 












I'm looking for safe ideas in where to mount mt fuel pressure regulator. Real estate is hard to find. I'm not too keen on mounting it to the brake ABS assembly, but it might actually be a good spot. Thoughts?

fuel regulator position.jpg
 






You could make a bracket coming off where the master bolts to the booster. I've done that for wiring harnesses. Also most non abs trucks have a bracket off the same place to support the brake lines.
 



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i'd chuck the upper on, then start looking for spots. like i was saying, where i have mine is kinda good....sorta. can see it fine, but adjusting it can be a *****. then you might also have the exact opposite, where you can adjust it fine, but cant see it
 






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