Too much return fuel?

[w123suv]

I am getting ready to convert to electric fuel pump and… I am using a raptor pump which I know is overkill but it has a lifetime warranty and I already own it so thought I might as well use it. On a previous IDI I had been using it without a regulator and all the way turned down it still put out 10 PSI which caused loud idle and maybe had my timing out of whack? (I just recently learned about this)

On the new idi I have a regulator with return that I plan on setting at 5-7 psi. I would like to mount the regulator under the hood (this is a van) and tee the return into the overflow line off the filter. My question (finally) is: will I be returning to much fuel at that point for the low pressure lines around the injectors to handle? The pump is the 150 GPH model. I don't know if it moves less when you turn it down or not.

 

[BDCarrillo]

It appears that you'd be returning about 120 gph... way overkill on stock 5/16 return lines. I don't know if it would generate too much backpressure on the return lines... a dedicated run to the tank would be ideal.

Turning down the pressure would send more through the return.

 

[FarmerFrank]

I've had troubles with regulators and large pumps.

I tinkered with this for a while when I got my truck and was trying to run WMO ( before I even knew other people did it too) The big problem I kept hitting was fuel would take the easier route, which for me was the return for the regulator. Took a lot of head scratching to figure out why the truck would dr goin down the road randomly.

I pulled the filler neck off my rear tank an welded a fitting and that's where the return for the regulator went to but I only had 1 tank at that time.

I now run a Mr. Gasket 105p pump and tweaked it to get oil through mu filters. Pushes 14 psi all day. Time the pump with the higher pressure. Messes with the timing advance curve but the truck runs great so I don't care.

Best of luck with it and to answer your question, try to T your regulator behind the T where all the returns from the injectors hit instead of before them. Might reduce the risk of leaking injector o-rings.

If it is in fact too much fuel and the IP return can't flow the truck will shut off so you will find out

 

[jaluhn83]

Probably should run a dedicated return line. Problem is going to be switching tanks - you'll need another switch valve.

Any increased pressure in the return lines is going to cause leaks and running issues. One of the few failsafe ways of killing an idi is the clamp the return line off the injection pump.

 

[w123suv]

I should have said that the van is a 92, so only one tank. I was planning to mount the pump on the frame just in front of the fuel tank. Would mounting the regulator there right after the pump and spicing into the return line with a check valve solve any issues? The return line at that point is 3/8.

 

[franklin2]

I am not sure how much GPM of fuel one cylinder uses, but when I was on a trip a long way from home and had one of the injector lines crack, I turned the line around and put the good side on the IP, cut the bad end off, and took the rubber return line from the filter head and stuck it directly onto the bad injector line. It ran fine on 7 cylinders for about 300 miles till I finally found a new hard line. The return system took all that extra fuel from that one cylinder and didn't blow any lines off, and didn't have any leaks. I believe I used a wire tye as a clamp to hold the return line onto the hard line.

 

[idiabuse]

my truck is all plumbed 1/2 dia pressure and return lines and 5/8 dia from the tank to the screen filter and MrGasket 70gph pump I run around 5/6 psi I just knew long ago I had to replumb my truck if I wanted it to run right. I daily drive mine lately. I will switch pumps with ya!

 

[w123suv]

Larger lines throughout would probably solve any potential problems but i would rather not get into that much work if I don't have too. Is a check valve a bad idea? Love the make it work story. I had to read that a few times to understand what you did. Good thinking!

 

[w123suv]

I guess the real question is wether having a regulator will cause excess return flow. On the previous vehicle the pressure was a little high but no fuel was returned at the pump or a regulator. So if the stock system handled everything without a regulator is this bypass regulator that I was planning to install going to let a ton of fuel bypass in order to get the pressure down a few psi?

Maybe I should just buy a carter pump?

 

[BDCarrillo]

Why not add an inline filter after the e-pump that uses better filters (1-2 micron)? It would likely drop the pressure a tad and preserve your injection bits.

The DB2 manual calls for much better filtration than the stock filter provides.

 

[w123suv]

Can you recommend a filter/ head?

I have the regulator so I'm less worried about pressure than I am volume. At this point I'm thinking to install the regulator right after the pump and tee the return into the return line with a check valve. Everything would be pretty close to where the lines go in and out of the tank. Nothing changed on the top.

I do like the idea of relocating the filter though as its location sucks in the van.

 

[BDCarrillo]

Racor makes some pretty good setups and they are high quality filters.

I think a relocated filter is a good use of the excess flow you have and will slow things down a tad.

Teeing into the factory return with a check valve may still cause problems IF the regulator bypass flow is stronger than the bit of fuel that lubricates the injector on it's way to the return system.

Frankly running a dedicated 3/8 rubber line back to the tank would eliminate any possible problems and be ~$20.

 

[w123suv]

How would you plumb that return line into the tank? I've never had the tank down to look at the top of it. Would I need to weld a fitting on? Don't have a welder, so looking for an easy solution. I'll look at racor.

 

[BDCarrillo]

You must be registered for see images attach

F-250 saddle tank sending unit (rear and van should be similar). Plenty of area to drill a hole and install fittings.

You must be registered for see images attach

 

[w123suv]

That doesn't look to bad. Thanks for the part numbers. I'm guessing there is a way to reach inside the tank then?

If you were me would you just sell the raptor, buy a carter or other hundred dollar pump, with correct psi and gph, do away with the regulator and be done with it?