Biting the bullet: Converting to electric fuel pump

[Cubey]

Pretty much ignore that entire last post of mine above.

I still can't go faster than 70mph even when floored, despite the pressure sitting right at 5psi.

I removed the Racor, so now there's just:

Tank->strainer->pump->stock filter->IP

Now what?

Kickdown rod adjustment maybe?

 

[Cubey]

Is it just me, or is the RV's kickdown screw in way too far? It limits the kickdown rod movement quite a lot.

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My F250 for comparison:

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[Cubey]

In reality, the screw needed to be even futher in, not out. At least compared to the kickdown rod movement vs the truck. So I adjusted it. No change.

Flooring it never gets me back to second still for some reason, heck knows why. Probably a whole other problem that needs its own thread.

This has me beat. I'm out of ideas. Surely timing wouldn't cause a 70mph top speed? No noticable smoke, but my fuel gauge seems like it's dropping like a lead balloon, even for this thing. But who knows, maybe I'm just guzzling doing these test drives.

I double checked my fuel line connections, everything is right. So I know I'm not returning to the wrong tank.

If somebody doesn't think of something within the week that helps solve this, I guess I will have to admit defeat and put a new mechanical pump.

70mph top speed ain't gonna cut it. I've been up to 75mph to pass merging traffic in this before and there was more speed available, so I know its not a pre-existing condition.

 

[Cubey]

I pulled off that long 2ft looping hose I put to bridge the lines in place of the mech pump. The stuff is fuel hose, but it's standard duty. It almost feels like it might be collapsing in due to the loops, even though they were large.

I put on this short piece of continental hose i used for power steering return hose, but no longer needed with the new return line and hose assembly. Its much more sturdy and doesn't squish as easily as the other stuff.

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It's probably not a collapsing fuel hose problem, but you never know. It only cost me time to change it.

Now it's getting dark, so I'm done for the day. I'll test drive tomorrow and report the results.

That was basically the only other new thing except the glass strainer right before the pump. (And various brass fittings). It has already caught some specs of dirt/rust so I really do need a filter of some kind to help save the pump. I guess I could remove it long enough to drive 3 miles to see if it's still a supply to pump problem. That's a last ditch effort thing but I guess I might have to try it.

 

[Booyah45828]

Looks like it's consistent.

Gets down to just over 5 when you have your foot into it.

And back up to over 7 when you let off.

I'm betting 5 pounds of pressure is delivering sufficient fuel. I'd try the timing.

I agree, If you're at 5 psi with the electric, I don't see how you'll gain anything going back to the mechanical. Maybe check return line restriction to see if that is the issue. Do you have a boost gauge? If so, had that changed at all throughout this process?

 

[Cubey]

I agree, If you're at 5 psi with the electric, I don't see how you'll gain anything going back to the mechanical. Maybe check return line restriction to see if that is the issue. Do you have a boost gauge? If so, had that changed at all throughout this process?

The only thing that has changed on the return line is a pex tee branching off to the tank transfer pump. Yeah, I can try removing that and see if it'll help but I doubt that could be the problem. Supposedly there isn't a ton of return, or at least not a lot of pressure.

I guess i can stick the return hose into a bucket and start the engine to see how much comes out at idle. Not sure what that will tell me though except return is flowing.

I forget to check boost. It's hard to see when driving, due to it being mounted down low, blocked by the steering wheel. EGT is not much better, but is slightly. I will try to remember to check it tomorrow. What would a change in boost mean?

 

[Thewespaul]

Try dropping the timing down a hair, you’ll get your power back. Your fuel supply is fine

 

[Cubey]

Try dropping the timing down a hair, you’ll get your power back. Your fuel supply is fine

I still plan to visit the shop I mentioned to you in PM. Glad I waited, I'd have wasted the money doing it before. (Like I figured)

It's about 165 miles back that way on the interstate, but it can cruise ok at 55 so I will just hold out for them to do it. I got in contact with em on FB and they said timing a van chassis isn't a problem.

Of course, the local diesel pickup shops around here don't know crap about IDIs. Even the International dealer. It's just been too long I guess.

 

[Booyah45828]

The only thing that has changed on the return line is a pex tee branching off to the tank transfer pump. Yeah, I can try removing that and see if it'll help but I doubt that could be the problem. Supposedly there isn't a ton of return, or at least not a lot of pressure.

I guess i can stick the return hose into a bucket and start the engine to see how much comes out at idle. Not sure what that will tell me though except return is flowing.

I forget to check boost. It's hard to see when driving, due to it being mounted down low, blocked by the steering wheel. EGT is not much better, but is slightly. I will try to remember to check it tomorrow. What would a change in boost mean?

There shouldn't be any return pressure, but there is return fuel flow, if it's restricted to the point it gives you any measurable pressure you could see some power loss.

Lower then normal boost pressure would confirm your lack of power, maybe show air restriction or some other problem. I'm just spit balling. Same with egts.

But I'd say your fuel pressure is fine. So I think you can take the Holley black out of the shopping cart.

 

[Shadetreemechanic]

So you replaced the racor filter on the head today with a higher micron filter? I believe the pressure at the schrader valve on the filter head is prefilter, so the only restriction on the supply side you have left could be the filter itself and you wouldn't see that supply problem on your gauge.
Otherwise I would look on the return side as well. You may have a timing issue, but it should have shown up before the pump swap. I don't think the minor change in supply pressure would mess with timing much, so it sounds to me like you still have an issue that is tied in with your pump conversion.

 

[ifrythings]

@Cubey Just a suggestion, RELAX! Your pushing yourself through a emotional rollercoaster with this e-pump swap.

Now I think your problem is the IP is pulling fuel out as your approaching the governors limit. Assuming tire size as 235/85/16, c6, 4.10 rear @ 70mph your engine will be reving at 3211rpm which is where a lot of IP’s will start pulling fuel.

When it was -40 here a few weeks back and my e-pump wasn’t keeping up I was seeing -7.6(psi? gauge isn’t calibrated for vacuum yet) and my engine started to buck just like running a tank empty, higher gears seemed easier for it to keep up as 2nd and 3rd would easily suck the pressure to negative valves instantly, 4th and 5th would run around -1 to -2 on the gauge and still be drivable. These IPs are very tolerant of fuel flow into them and you have plenty at 5psi.

Here’s a good gear calculator I like to use www.grimmjeeper.com/gears.html

As for fuel mileage keep in mind your trying to drive a cruise ship down the road not a pickup.

 

[Cubey]

So you replaced the racor filter on the head today with a higher micron filter? I believe the pressure at the schrader valve on the filter head is prefilter, so the only restriction on the supply side you have left could be the filter itself and you wouldn't see that supply problem on your gauge.
Otherwise I would look on the return side as well. You may have a timing issue, but it should have shown up before the pump swap. I don't think the minor change in supply pressure would mess with timing much, so it sounds to me like you still have an issue that is tied in with your pump conversion.

No, back in mid-late December, with the mech pump installed before i noticed it weeping, or right before it began, I installed a Racor head with a used 2 micron filter I got back in 2017 from a junk yard IDI. I figured I might want it some day. It seemed to be negatively effecting startups and driving, so I disconnected it. Its a matter of just swapping around 2 hoses, no major work. I figured so much restriction before lift pump was the problem.

I ordered new 2x 30 micron filters which I got my hands on in late January. When I did the Holley red install, I put on a new 30 micron and reconnected the head.

Since disconnecting today made no change in fuel pressure, i just now reconnected it. (I didn't post a video of that test drive, since nothing changed)

There is really nothing to check on the return line. I didn't do anything to cause it to be restricted, except maybe the 3/8" PEX tee, but that's higly unlikely. I already checked that thr hose isn't squished around the Holley somehow, and it's not.

Fuel pressure does screw with timing. Everything I'm seeing says the IP expects 1psi at max RPMs, and it's getting 5 right now.

I have good power for city driving, but once i hit around 50-55, I'm lacking power. At 70, there's no more power.

So it makes sense that at 70mph, timing would be screwed up getting 5psi instead of 1-2 it would normally see. At lower rpm/speed, the IP expects higher pressure (5-7psi) so acts fine then.

The timing is off just so that drive fine until you try to get that top end power.

Remember, this is the original IP (~75k mi.) and it's probably never been touched since it was in the factory.

 

[Cubey]

@Cubey Just a suggestion, RELAX! Your pushing yourself through a emotional rollercoaster with this e-pump swap.

Now I think your problem is the IP is pulling fuel out as your approaching the governors limit. Assuming tire size as 235/85/16, c6, 4.10 rear @ 70mph your engine will be reving at 3211rpm which is where a lot of IP’s will start pulling fuel.

When it was -40 here a few weeks back and my e-pump wasn’t keeping up I was seeing -7.6(psi? gauge isn’t calibrated for vacuum yet) and my engine started to buck just like running a tank empty, higher gears seemed easier for it to keep up as 2nd and 3rd would easily suck the pressure to negative valves instantly, 4th and 5th would run around -1 to -2 on the gauge and still be drivable. These IPs are very tolerant of fuel flow into them and you have plenty at 5psi.

Here’s a good gear calculator I like to use www.grimmjeeper.com/gears.html

As for fuel mileage keep in mind your trying to drive a cruise ship down the road not a pickup.

I'm a worrywart, what can I say?

215s are what vans call for but yes on the rest.

I've been driving it for a year so I'm used to the mpg, but it seems a bit worse since I installed the Holley. But that's probably due to off timing, just like the missing top end power.

That ball valve definitely did restrict flow.

And after I messed with removing it, now the glass strainer is starting to leak. It comes apart to change the element, so I gotta loosen a hose clamp so i can tighten it back together. It had no leaks prior to me touching it today.

I might just go buy a cheap metal one that won't be prone to leaking like this silly fancy glass one.

 

[Booyah45828]

Fuel pressure does screw with timing. Everything I'm seeing says the IP expects 1psi at max RPMs, and it's getting 5 right now.

I have good power for city driving, but once i hit around 50-55, I'm lacking power. At 70, there's no more power.

So it makes sense that at 70mph, timing would be screwed up getting 5psi instead of 1-2 it would normally see. At lower rpm/speed, the IP expects higher pressure (5-7psi) so acts fine then.

And that's something I hadn't considered. I was assuming we were chasing a low pressure from the pump upgrade, but if it actually raised your pressure, then maybe your timing is advanced too far and causing the low power. Most like the timing more advanced than stock, but I can say without question my bus is faster around 6 vs anything higher then that.

 

[Cubey]

And that's something I hadn't considered. I was assuming we were chasing a low pressure from the pump upgrade, but if it actually raised your pressure, then maybe your timing is advanced too far and causing the low power. Most like the timing more advanced than stock, but I can say without question my bus is faster around 6 vs anything higher then that.

Sorry if I caused confusion.

Once I put the tester on yesterday, I knew it wasn't lower than 4.5psi, which I mentioned.

After removing the ball valve today, it got about a 0.5psi boost. I will just leave the valve off since it's not THAT messy to disconnect the hose for filter/pump maintenance. Hopefully that won't be needed for years anyway once I get this all done.

The glass pre-pump filter is kind of a pain, so that's the only thing I might change later, if it starts leaking again after I tighten it back. I think it just loosened when I pulling the ball valve off but we'll see.