Biting the bullet: Converting to electric fuel pump

[The_Josh_Bear]

Here is a diagram I drew of the stock return line setup. Without the soft line between the injector cap and the filter housing, air in the (orange) hard line has no where to go hardly except into the IP and to the injectors. Maybe that'll solve the problem right there. The olives on that hard line might be weepy from leaking, so I'll keep an eye on that.

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Your theory about the OEM return setup is correct. There is a very good reason they all came this way, purging air is a priority. And if you ever fail to switch tanks fast enough the way your setup is now, every ounce of air goes through the IP instead of some percentage being purged. I've done it both ways and it's a LOT faster to recover with the OE setup.

And since you have your E-pump, you now have no excuse (edit: NOT) to go back to the OE style return! Free air purging! Another cool deal is that a LOT more air can go through that tiny orifice than can diesel, which took me a long time to realize. So a tiny stream of diesel goes through that but a boat load of air can run through the same passage. Pretty good setup really.

Without having memorized your fuel setup, you'll just need one check valve somewhere between your fuel tank and your fuel filter to prevent drain back. Unless the Holley or regulator already has one built in, then you won't need an extra.

 

[Cubey]

And since you have your E-pump, you now have no excuse to go back to the OE style return!

I don't understand what you mean by that.

Shouldn't I have it set up like the diagram I drew, even with an e-pump? It's not hooked up that way right now. The connection from the cap to filter isn't connected. It has been fine until Friday... as soon a temperatures dropped within 2 weeks of messing with that hard line during timing, I started having air intrusion issues. I'm guessing I need that stock setup to prevent that (due to bad olives in that hard line), no matter if if it's a mech lift pump or an e-pump.

Yes, the ideal solution is to replace the olives so no air gets in, but since I have an e-pump to purge the air for me, the stock setup should band-aid the problem for now. It's not at all easy to get in there to mess with that hard line. Unless the olives are leaking badly, I see no point in messing with them any time soon.

I have the low pressure (lift) system set at something like 4psi max so even if the return line sees half of that at the injector caps, it shouldn't hurt anything. The return line to the tank should always be free flowing since it's just a hose entering the tank basically, nothing at the other end to stop the flow and pressurize the system that much.

 

[The_Josh_Bear]

I don't understand what you mean by that.

Shouldn't I have it set up like the diagram I drew, even with an e-pump? It's not hooked up that way right now. The connection from the cap to filter isn't connected. It has been fine until Friday... as soon a temperatures dropped within 2 weeks of messing with that hard line during timing, I started having air intrusion issues. I'm guessing I need that stock setup to prevent that (due to bad olives in that hard line), no matter if if it's a mech lift pump or an e-pump.

Yes, the ideal solution is to replace the olives so no air gets in, but since I have an e-pump to purge the air for me, the stock setup should band-aid the problem for now. It's not at all easy to get in there to mess with that hard line. Unless the olives are leaking badly, I see no point in messing with them any time soon.

Sorry, you have no excuse NOT to go back to OE style return.

 

[Cubey]

Sorry, you have no excuse NOT to go back to OE style return.

Gotcha. I do the same, forget a single word that totally changes what I'm saying.

 

[The_Josh_Bear]

Gotcha. I do the same, forget a single word that totally changes what I'm saying.

Right?! It's one of my big peeves too because proofreading isn't *that* hard, and if I can do it, anyone can! But of course I mess up too.

 

[Cubey]

Right?! It's one of my big peeves too because proofreading isn't *that* hard, and if I can do it, anyone can! But of course I mess up too.

I often edit my posts half a dozen times because I notice mistakes or think of something to add.

 

[Selahdoor]

I was beginning to think my post had gone completely over everyone's heads...

 

[Cubey]

Dang. The fuel transfer pump must be going bad. It's blowing the fuse now. It had a 7.5A fuse I put when I wired it up. I just tried a 10A and it also blew it within a minute. Stinks since I have a rear tank full of fuel. I mean, I could pump it out with a hand pump into a 5gal can if I had to. But nah, I'll just leave it until spring when I put a fuel tank selector valve back on. That or buy another one or two 5gal cans and just refuel that way. Kind of a pain to have to do it that way, but no risk of a valve going bad. I'll worry about that in 4-5 months.

On the plus side, I guess the front tank's shower head is still on too. I was biting my lip on the drive to Roswell earlier. It got between 1/4 and the empty line, but I made it.

Back on the topic of the fuel return line setup, I put the soft line back to the fuel filter this morning. It started and then almost stalled out (very low rpm) but not quite, then came back up. Fair enough, I had the system open to connect the hose so air was in there. I'll have to see how it does tomorrow morning before I can say if that will fix the issue.

 

[Cubey]

Hm, not sure why it didn't say want to start this morning. It was either gelled fuel or glow plugs. It got down around 25-27 early this morning and I didn't have antigel additive in it because the forecast didn't show that cold. It showed 32ish. Well it flat out didn't want to start. It kind of hiccuped a couple times like one cyl fired but nope. It acted like no fuel or no glow plugs.

I did notice that the fuel pump sounded kind of funny when I first turned the key, so maybe it was gelled just enough to cause a blockage in a small passage.

The Onan generator behaved well enough to run the block heater for 5-10 minutes. The cord's plug got warm so I decided to try to start it and it did easily. When doing that, the Onan just happened to stall. If I can't get that stupid thing to work reliably, I might just get a good used 2k watt inverter generator and keep that on hand for emergency block heater use. Also handy for the microwave and RV water heater (if I don't want to use LP).

Maybe the block heater was a red herring since it ran for such a short amount of time. Hard to imagine that was enough to warm up a cast iron block. Maybe fuel just happened to got flowing enough despite minor gelling finally after so many tries on the try after I had the block heater on.

It didn't start then die like air intrusion. I could swear I smelled faint diesel when I lifted the hood to check for fuel pressure at the filter valve. Maybe it's just from the intake since the filter has no cover, just the retaining ring. I never smell it after driving when I go to check the oil level so I don't think there is a leak.

Yeah that's going a bit off topic but not really since I noticed the fuel pump noise variation. Had no problems in the 250 miles I drove and the many starts on the warm motor.

On the subject of the soft return line reattached to the fuel filter/metering valve fitting, I could swear it has slightly improved the mpg. Nothing wild but it does seem better. Unless New Mexico's diesel quality is far superior to Texas'. I crossed into Arizona today and filled up in San Simon and it seems like the slightly better mpg is still with me, even with some steep climbs where I have to drop to 2nd to control EGT. Had to drop to 1st on one even. Course the 3-4 mile descent where I barely had to give it throttle made up for that.

Head winds are evil to tall IDI RVs. That's what slows it down so much and makes EGTs climb when trying to maintain highway speed (55+), especially on hills. I just let everyone pass me. If I drop much under 55 on a hill, the hazard lights get turned on.

 

[IDIBRONCO]

I doubt that it was gelling at 25-27*. The fuel that comes out of the pumps is blended right in colder climates. I've run straight pump fuel with no additives at much colder than that. The only chance that I can see where it could have gelled is if there was a lot of wind. Weren't you having glow plug issues before?

 

[Cubey]

I doubt that it was gelling at 25-27*. The fuel that comes out of the pumps is blended right in colder climates. I've run straight pump fuel with no additives at much colder than that. The only chance that I can see where it could have gelled is if there was a lot of wind. Weren't you having glow plug issues before?

Well the fuel was bought at the auto diesel side in southern New Mexico so maybe they weren't giving it the antigel? Who knows.

Nope, I never had glow plug problems on the RV. I ran the block heater a few times last year when I happened to be on grid in free Texas town's RV parks when it got very cold but in general, nope never had a problem.

The F250 did in 2017. It had autolites that were half burned out. I put in new motorcraft plugs. It also had the glow plug solenoid go bad.

They could very well be the originals on th RV and are starting to finally show their age. It's supposed to be about 37F low overnight where I am now, so we'll see how it does in the morning.

It didn't sputter like it had air after it started so I guess that issue is resolved.

I saw a cheapy but well reviewed 2000w generator for $300 on Walmart marketplace. A set of zd1a plugs cost about $100. I'd rather spend the money towards something more versatile like a bigger inverter generator that can run the block heater and more. The 1000W block heater is too big for my beloved 500W Yamaha generator. A modern inverter generator with eco mode (lowers RPMs with 25% or less load) can probably be as efficient.

Yeah it's not as convenient dragging out a generator vs running glow plugs but I'm rarely in a hurry on cold mornings.

I'd rather spend little to nothing to get the Onan working properly though since that it's there.

 

[IDIBRONCO]

Nope, I never had glow plug problems on the RV.

I thought that when you were here, you said that once in a while they wouldn't kick on and you had to turn the key on and off a couple of times to get them to come on. Maybe I'm wrong though.

 

[Cubey]

I thought that when you were here, you said that once in a while they wouldn't kick on and you had to turn the key on and off a couple of times to get them to come on. Maybe I'm wrong though.

Oh yeah, that. Well that has to do with the solenoid, not the plugs themselves. Wait to start wouldn't light up because the solenoid didn't activate and it would take a few times to get it to work. WTS was coming on this morning, and I can hear when the plugs are on because the Holley fuel pump's tone changes due to the load change on the batteries. I didn't have that audible clue with the mechanical lift pump. So at least some are heating, since a voltage drop occured.

 

[Cubey]

They keep underestimating lows. It was 32 this morning. As soon as I got up, I fired up the glow plugs. They ran the usual long time (under 10s) then I shut off the key for about 15secs (so the pump wouldn't run). Then turned it again and they only ran about 4 seconds. Cranked it and it fired up okay without excessive cranking, just idled slightly rough like maybe 1 or 2 weren't hot enough yet. It wasn't too bad nor did it act like it wanted to stall. It let it smooth out and idle for about 30 seconds more before shutting it off. Very strange how it acted yesterday morning. Yesterday, I switched to using the Power Service white bottle (winter/antigel) that I already had from last year, so maybe that helped? I was using the grey bottle up until then. I didn't notice the fuel pump sounding funny when powered on like yesterday morning.

 

[The_Josh_Bear]

I know this will sound a bit random but where is your pyrometer located?

As for the fuel gelling you're probably right that in Southern NM they wouldn't be blending the fuel yet and even the slight freezing caused gelling in the lines. Then presto as soon as you use the white bottle everything is good to go.