Fuel pressure regulator

[Garbage_Mechan]

The explination of how the pump works is correct. However they don't shut off because we have an orfice returning fuel to the tank so there is flow even if there is no use.

Think of the pulse pump like this:
A bicycle pump that you pull up on the pump handle and it is spring return. the spring force is what regulates the output pressure; when the handle is all the way down a little bell rings to tell you to pull it up again. If there is no flow (head pressure) then the pump handle will reach the bottom of it's stroke so you don't pull up again. If there is flow then the handle will lower at the required rate until the little bell rings.

The only difference in the electric pump is that the solenoid contacts are closed when the piston bottoms out, triggering a new cycle. The really nice thing about this is that there is only power used when fuel is needed, and the higher the fuel needs, the faster the pulses. The electric 'whine in the tank' style is on 100% of the time.

The pulse pumps (probably diaphragm) are positive displacement with efficient check balls; that is why they are self priming. The motor type probably use a vane and don't create vacuum well.

 

[Garbage_Mechan]

Why argue with the guy who developed an markets the best pumps for our engines? He owns a fuel injection shop........

I've heard numbers from 5-10 as to what the stock pump needs, I checked my stock pump and it was putting out close to 6.5.

What do you think'll happen if I run 8?

 

[leswhitt]

Not arguing at all, just wondering what'll happen if I run 8 psi instead of the 5 that the pumps are calibrate for. Since my stock lift pump is at 6.5, certainly there's a variation level. As you said, he owns a shop, obviously knows his way around an IP, and I'm interested to hear his opinion.

 

[jaluhn83]

Bottom line - the increased feed pump pressure should have little impact on the truck running.

The transfer pump & regulator setup are speced to deliver ~60 psi at idle and ~90 at max rpm. This pressure is regulated relative to the supply pressure, which is speced for 5 psi to calibrate. So increasing supply pressure from 5-10 psi will increase the internal pressure the same amount (in theory) which should cause a sight advance in the timing at idle and slight change in the timing curve. Doubtful it would really have much of any noticeable effect though.

 

[Ugly Moosling]

I've experimented with feed pressure vs advance. Every pound above or below 5psi will affect timing by roughly .5 degrees. Hanging between 4-6 psi should have little effect on the timing curve other than moving it slightly up or down in the rpm range. At 8 psi feed you may see 1-2 degrees extra advance at any given rpm. As was mentioned, most rebuilders calibrate to a specific curve using 5 psi feed on their machines. Most people probably wouldn't notice a difference until you get to 8 psi or above. It would be interesting to see someone dyno a truck with a timing tool attached and see what gains or losses could be made by changing feed pressure and adjusting the dynamic timing accordingly.

 

[Ugly Moosling]

In addition to the above post, altering feed pressure had no effect on fuel delivery whatsoever.

 

[leswhitt]

Started back working on the truck this week and one of the tasks was to solve the hard starting and lack of glow plug activation.

In curing the hard starts, I have a PSD pump ready to go in and went ahead and installed the fuel pressure regulator today. Installation wasn't very difficult but there was a return line on the stock system that I didn't quite understand but I was able to leave it alone (return line on the front DS looped back into the fuel line going to the IP).

I found a digital psi gauge and sender on Ebay ($20 shipped) and will wire that in rather than leave the underhood gauge in place. The return line off the FPR will be only for the FPR, I don't plan to tie it in to the stock system and maintain the KISS principle. Here's some photos instead of just a wall of words.

As you'll see from the photos, I have dual fuel filters and my planned setup is tank>psd pump>filter #1>filter #2>fp regulator>ip.

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[leswhitt]

Alright, a couple weeks later and I've wired up the glow plugs for manual activation (works great), installed the PSD fuel pump and wiring (works great), and tested it out. What I found was that the cheapo Ebay regulator is NOT the return style and was building mucho pressure in the system. To fix it and test the concept without buying a new regulator, I put a bypass ball valve after the first filter, slowly cracked it until the digital fuel pressure gauge ($20 Ebay gauge is good to go) after the 2nd filter read 10 psi, let it pump for 15 seconds, turned the key, and the truck fired up within 5-7 seconds after sitting for a few weeks.

With the key off, my psi sits at 10, idling I'm at 8-9, and I expect that it'll drop to 4-5 when I'm rolling down the road. Now that I know it works, I'll test drive it for a while and see if the ball valve is a long-term solution. If it is, I'll just epoxy the handle so that it can't move and keep on trucking. If not, I'll end up buying a Carrier/Facet pump since the cost is nearly the same as a regulator with a return.

 

[leswhitt]

Forget the Carrier/Facet, I was looking online for more pump choices and saw the E8012S for half the price with a lifetime warranty. On top of that, there's a seller on Ebay that's letting them go for $15.75, free shipping included. I wish I had seen that before I purchased the non-return regulator, I would've saved money and time...

Disclaimer - I don't know the seller or have anything to gain from his sales.

http://www.ebay.com/itm/NEW-GLOBAL-...ies&hash=item53fc725222&vxp=mtr#ht_1703wt_916

 

[ryanecvbrown]

Started back working on the truck this week and one of the tasks was to solve the hard starting and lack of glow plug activation.

In curing the hard starts, I have a PSD pump ready to go in and went ahead and installed the fuel pressure regulator today. Installation wasn't very difficult but there was a return line on the stock system that I didn't quite understand but I was able to leave it alone (return line on the front DS looped back into the fuel line going to the IP).

I found a digital psi gauge and sender on Ebay ($20 shipped) and will wire that in rather than leave the underhood gauge in place. The return line off the FPR will be only for the FPR, I don't plan to tie it in to the stock system and maintain the KISS principle. Here's some photos instead of just a wall of words.

As you'll see from the photos, I have dual fuel filters and my planned setup is tank>psd pump>filter #1>filter #2>fp regulator>ip.

You must be registered for see images attach

You must be registered for see images attach

The return line from the cap going back to the IP supplies a small amount of fuel back to the IP under high-demand situations. I still have clear fuel rated hose on my return system from when I was doing some diagnosis awhile back. It was kinda neat to see small bubbles change direction during throttle position cycles. At the time the punt of fuel returned to the IP from the fuel return circuit was sever because I had a massive restriction at the tanks where the factory fuel lines had kinked. Demand from the return sys was so high that after 30 seconds of 2000rpm no-load operation it would suck all fuel lines dry!! No more air bubbles but it's nice to have the clear lines in there if the need for fuel system diagnosis arises.