Automatically priming fuel system hack

[Bart F-350]

I didn't say it failed, I said (from what I read) that they regular have difficulty in getting the correct volume of diesel to the IP.

 

[Kevin 007]

This is a topic that has gone thru and will continue to go through revisions. QC changes on everything, circumstances change, etc etc. It's good to keep this discussion going as there will always be updates on QC of all pumps, ways to install them, results etc. That's what's great about forums. I've converted to electric for no reason other than reliability and I have discussed it plenty on other convo's and am always happy to add any new findings and listen to others in their adventures.

 

[XOLATEM]

This...in lieu of a cupholder pic...

 

[tbowker]

Long live the cupholder thread!!!

 

[IDIBRONCO]

but tell me of a vehicle made after 2000 that has a mechanical pump?

I can but it might not count since it wasn't made in the U.S. and I didn't see the engine personally. What I was told may not be true. When I was in Iraq as a civilian contractor, the last bus that we were given (to get to work and back with) was a 2001 Nissan bus. I don't remember how many passengers it would hold, for some reason 26 seems to stick in my mind, but the other team of mechanics (not the one that I was on) was trying to fix it after it conked out. One of them told me that it had a carb and a points ignition. If it did, then it surely would have also has a mechanical fuel pump. So...maybe there was a few?

 

[Bart F-350]

As you said.
people living in modern (mostly) cities doe often not realise that there are many many area's on this globe (earth) that do not yet live in the same luxuries as they do.
Many laws are made by those people, trusting that those laws are made for people in the same circumstances, and so it happens that sometimes those laws are impossible to follow due to the fact that if you are living in old fashioned rural country (for example!) you not even have the amenities to accord to such laws.

I hope you can grasp the Idea of what I try to say here, my knowledge of the English language is insufficient to put it in another way, sorry.

 

[IDIBRONCO]

As you said.
people living in modern (mostly) cities doe often not realise that there are many many area's on this globe (earth) that do not yet live in the same luxuries as they do.
Many laws are made by those people, trusting that those laws are made for people in the same circumstances, and so it happens that sometimes those laws are impossible to follow due to the fact that if you are living in old fashioned rural country (for example!) you not even have the amenities to accord to such laws.

I hope you can grasp the Idea of what I try to say here, my knowledge of the English language is insufficient to put it in another way, sorry.

Well said. I understood it just fine.

 

[Linctex]

Oh, forgot to mention, If the engine has sat for long enough for it to energize the fast idle solenoid, then you'll also be priming the IP housing.

Or, just depress the accelerator pedal a little bit . . . . Which is a normal thing, anyway - when starting these engines.

 

[franklin2]

Update on my china pump; Something is going on with it, it sounds terrible and the truck started but quit on me. I got it started later in the day and while it runs, the pump sounds awful, very loud not a calm click click.

I need time, but I am going to pull it off and inspect it, and probably take it apart. I have been driving the truck in the salt lately, and I mounted the pump low on the frame on the pass side near the radiator. I have taken one of these pumps apart before and it's not sealed very well. I am suspicious salty water has gotten inside and corroded something. If it has, I think I am going to see if I can get it working, and move it up onto the pass side inner fender. While it will have to pull fuel up higher, it's rated for that little bit of height and it will be a cleaner environment.

 

[Daniel M Lemley]

I finally managed to fix all my fuel leaks, but I'm still dealing with an air intrusion issue. After sitting for a while, usually overnight, she starts and then dies after a couple of seconds. Then I have to crank for a while to get it started again. Afterwards it runs rough for a minute, then settles down and runs just fine for the rest of for the day. Classic air intrusion / fuel drain back issue. The correct thing to do would be to chase down the problem and fix it. But... I don't have any actual fuel leaks, and other than the rough starting, it runs just fine. And I'm planning to do a WVO conversion on this rig when winter come around. I'll take the time to actually track down and fix the issue at that point, but in the meantime, I wanted to do something to prevent the starting trouble.

I know some folks will run an electric fuel pump in parallel with the mechanical pump and run it to a momentary switch in the cab. But I didn't like the idea of running a switch, drilling the dash, etc, just for a temporary hack. So I present to you "The Auto-Magically Self-Priming Fuel System Hack"

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Electrical diagram on left, fuel diagram on right.

I put a cheap ~$20 fuel pump in line with the mechanical pump with a couple of check valves to control flow. Then, instead of running a switch to the cab, I pigtailed a relay. Fed the hot for the control from the ignition switch lead on top of the GP relay, and then grounded it out to the control terminal on the GP relay where the white wire is connected. Pulled hot for the pump from the hot side of the starter relay and used an inline fuse. Grounded the pump out to the passenger fender. Zip tied the relay and everything together on top of the passenger wheel well. If you wanted a cleaner or more permanent install, I reckon you could use a spare relay slot in your fuse box.

Connected like this, the electric fuel pump only runs when the glow plugs are running. Works like a hot damn! If the engine is cool enough to need to run the glow plugs, then it may have lost prime, so you'd probably want to run the prime pump. The cooler the engine, the longer the pump runs. If the engine is hot enough not to need the plugs, then it probably hasn't lost prime, so no need to run the pump. Once the wait to start light (glow plugs) turns off so does the electric pump, and you're good to start.

Basically you're only running the prime pump when you'd most likely need it, and running it proportionally to how much air may be in the fuel system. And it's turning off before the mechanical pump takes over. And it's all being done automatically. The only time I could see there being an issue is if you have a serious leak back issue, or if the truck sits for an extended period of time. Then the electric pump may not run long enough to restore prime, but in that case you could just cycle the glow plugs a couple of times.

Anyway, figured I'd share what I thought was a pretty neat hack. Cheers y'all!

Bumblebeer!

I was inspired by your post and bought all the parts and pieces to copy your thought. I have sporatic air ingress issues and thought this would be my priming solution. I also have an Amazon tank changeover valve to install, so while I'm down there (planning on putting my lift pump, T's and check valves tucked in the frame rail).

So, question is, most of a year later, how is your system working?