Mechanical V. Electric Fuel Pump

I just replaced my mechanical pump with an electric pump and it's a night and day difference!

The electric pump is more efficient and my engine runs a lot smoother as well.

For what it's worth, I stick to the theory that if it's not broke, don't fix it. Mechanical for me with the Blue Truck.

404000 Km , still running on my 2nd. Mechanical pump . Zero issues with this set up , see no reason to change .

Dski1991 said:

I just replaced my mechanical pump with an electric pump and it's a night and day difference!

The electric pump is more efficient and my engine runs a lot smoother as well.

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Ya there really isn't a reason that an electric pump should make an engine run "smoother" compared to a mech pump unless there was an issue with the mech set up, like air intrusion or starvation for example.

I do run electric for the reason of easier priming, and because good quality replacement mech pumps are getting harder to come by. ….as are electric however. But there are more options for electric as there are for mech pumps. And if installed in a smart way, electric pumps can be easier to change out upon failure, compared to a mech pump. Otherwise I would still be running mech pumps.

The ease of priming with an electric pump, after running out of fuel or whatever; can really be a big deal if you run your batteries down in the middle of nowhere trying to re-prime a fuel system on a mech pump engine. And having a more positive and quicker prime to the injection pump, reduces wear on the injection pump and the starter.

But don't quickly scab together an cheap e pump setup in a hokey way and expect it to last and give good results. Install a good pump, in an appropriate manner.

Kevin 007 said:

I do run electric for the reason of easier priming, and because good quality replacement mech pumps are getting harder to come by. ….as are electric however. But there are more options for electric as there are for mech pumps. And if installed in a smart way, electric pumps can be easier to change out upon failure, compared to a mech pump. Otherwise I would still be running mech pumps.

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The reason I like Holley Red (and by extension, Blue/Black) pumps:
https://www.holley.com/products/fue...components_and_service/fuel_pump_repair_kits/

Yeah the repair kits costs as much as mechanical pumps from your favorite parts retailer, but on my RV, the Holley's location is far easier to access and repair than a mechanical pump with far less mess.

This is how cramped it is for the mechanical pump on 91 and older vans:



Compare that to the frame rail mounted Holley. I can crawl under the RV very easily and there is a ton of room to move around to avoid having diesel dripping down on me. I have the pump connected with a 2 terminal weatherproof connector, so it can be unplugged, if it needs to be completely removed for repair. It was a lot more expensive than a mechanical pump but it's far less worrisome.

Cubey said:

Compare that to the frame rail mounted Holley. I can crawl under the RV very easily and there is a ton of room to move around to avoid having diesel dripping down on me. I have the pump connected with a 2 terminal weatherproof connector, so it can be unplugged, if it needs to be completely removed for repair. It was a lot more expensive than a mechanical pump but it's far less worrisome.

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Yea, being able to sit under the vehicle and service the fuel where you can stay dry is a good thing.

Yes. Regardless of the application or type of part, being able to service something or improving a design to increase servicability is a great improvment.

I have been using an electric on my rig since i fired it back up about half a year ago. I like it ok. wouldnt say i am in love with one over the other but my electric does the job. most of them have a filter before the pump, i learned that those can clog easily and cause fuel starvation. other than that i have been happy with it.

Covers up those damn sneaky cold O ring return line leaks, that coupled with a leaky fuel pump check will MAKE YOU INSANE. Nothing like a 10 sec start/run only to air up the pump.

Matt Leaman said:

I have been using an electric on my rig since i fired it back up about half a year ago. I like it ok. wouldnt say i am in love with one over the other but my electric does the job. most of them have a filter before the pump, i learned that those can clog easily and cause fuel starvation. other than that i have been happy with it.

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The person who put the cheap 12D pump on my F250 put a clear plastic filter before the pump's tiny pre-filter and it has done a good job catching bits of rust from the tank. I had to replace the filter once when fuel gelled one very cld morning and it made the element inside collapse, causing some random fuel starvation. ~$5 filter replaced and it has been good since.

The other day in Walmart, I noticed they sell this in the boat section. It has 3/8" hose connections. That's a good source for an in-line filter if you can't seem to find one easily anywhere else in a pinch. It's rated 40 micron.

I know this could ignite alot of flames here but I have found over my years with these trucks electric is the way to go to save on starters and well injection pumps and ease priming. The system I run is dual electric fuel pumps 2x cheap electric non rotary type I have a custom fuel tank on top of my flatbed 80 gallons+ and a custom 50+ gallon in the rear tank spot. The top one gravity feeds to the lower one I run 1/2 inch plumbing some say overkill yes I agree but try running used motor oil or used veggie oil on a cold morning before it warms up my setup runs 1/2 inch to 1/2 inch barbed strainer then 1/2 inch to the pumps then splits to each pump at 3/8 then exits pumps and combines back together as 1/2 inch then thru a heating log setup welded directly to my 4inch square log exhaust stack system. Then into my baldwin BF7587 fuel filter on a wix 24770 filter mount which is a 4 port setup I added a custom fuel heater system to both ports that would be plugged that do 125w-150w of heating each and is automatically controlled to keep fuel temps at 165f-185f and goes to injection pump almost fully 1/2 inch then about 6 inches before the injection pump I got a 8an 90 to 3/8 barb directly on the injection pump.

The fuel pressure runs 5-8 psi idle and 4psi minimum WOT and my filters do not plug from waste veggie oil and my fuel temps never exceed 195f going into injection pump so in short very reliable and I run waste veggie and waste motor oil together alot of times and add around 25% diesel to help with starting my glow plugs are also deleted to help decompress motor. I use a intake heater from a powerstroke 7.3l in the intake where the CDR was with a 20sec burn and it starts down to around 45f fairly easily below this I need a little help no intake heater on and custom propane injection system on demand. This gets it to fire around 20f and above below that I need ether I made a system that disperses the propane and ether evenly in gas form so it wont really cause issues. I will say this anything below around 30f I try to plug it in or I run the onboard genset under the flatbed passenger side to keep engine warm and batteries warm / charged and ready to go using the genset or plugged in method I have been able to run my truck in -45f temps and such without issues and with my fuel heating setup again no gelling I have other heating sources on the rig also that heat the tanks themselfs and also warms or cools the fuel to engine temperature before entry into the injection pump.


I forgot to mention this I delete the factory fuel filter the quality on filters for the 6.9 / 7.3 idi in parts stores is horrible so I upgraded to the baldwin BF7587 setup and the WIX 24770 filter head under the truck and to be honest can get the baldwin which is a much better filter for cheaper and holds much more dirt and filters much finer than you can the factory style filters and again parts stores filters most are garbage pay close attention at the divider seal seperating the dirty side of filter from clean side often they got a gap or the seal only is sealing half way this means grit and dirt is going directly into your expensive injection pump / injectors. I found many wix / napa gold / motorcraft and others also this way new out the box straight from parts sellers hands to mine and right back into theyres it goes after I open it and look at it and find this issue only to find out it was only one they had in stock leaving me in a bind.


https://www.ebay.com/itm/7-3-IDI-AN...NE-TO-INJECTION-PUMP-UPGRADE-KIT/293819999158 modified injection pump feed line he sold me the adapter for the injection pump itself and the 90 barb fitting which I upgraded myself to a better one I had and the adapter i drilled it out to get maximum flow https://www.ebay.com/itm/7-3idi-Hard-fuel-line-upgrade-fittings-injector-pump-fitting-90-push-on-barb/293838909371?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649 he made a special listing so could buy just the fittings he has also got a few other mods I am going to test soon like the brass fuel return line caps https://www.ebay.com/itm/7-3-IDI-AN...URN-CAP-KIT-WITH-HOSE-AND-CLAMPS/293932946782


https://www.ebay.com/itm/Universal-Electric-Fuel-Pump-HEP-02A-4-7PSI-12V-Inline-Low-Pressure-Gas-Diesel/324130404697?ssPageName=STRK:MEBIDX:IT&_trksid=p2060353.m2749.l2649 had very good luck with these cheap fuel pumps not really had many issues I keep 2 spares in the truck and a few around the shop had 1 fail in past 2yrs so theyre very reliable just make sure filter is after the pump not before and make sure you have a screen system before the pump

https://www.ebay.com/itm/Inline-Str...387900?hash=item289af436bc:g:97IAAOSw8C9fKeJ- a good prestrainer before pump

I have both. Keep the electric on a manual switch,if you feel the truck is sluggish just hit the switch and ifmthings smooth out you know you have a fuel issue arising. Also great for priming filters and a back up for the mechanical.

Paul Petraitis said:

I have both. Keep the electric on a manual switch,if you feel the truck is sluggish just hit the switch and ifmthings smooth out you know you have a fuel issue arising. Also great for priming filters and a back up for the mechanical.

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I myself avoid both because if you have a issue with the mechanical pump the electric pump will keep things running but will fill crankcase with diesel wiping out your bearings / motor destroying the engine its 1 or the other not both both is a bad idea also mechanical pumps struggle with biodiesel and most diesel you buy has biodiesel in it from the pump add to it also modern diesel dont lubricate like old diesel did meaning increased risk of mechanical pump failure it is more drying than old diesel was aka causes the diaphragm to dry out and crack ( same reason our injector caps leak more now and seals in our injection pumps also fail more ) and it also will fill crankcase with diesel but usually will give you warnings like hard starting and lack of power when you push it and alot of times odd running behaviors like a sudden miss then rapid amount of power this is air getting into the system because of the mechanical fuel pump sucking air thru the pump diaphragm and putting it into fuel system pre injection pump sudden random spurts of what feels like you mashing the gas hard when your barely hitting it is often air getting aerated in the fuel injection pump and then being sprayed into the motor thru the injectors already pre vaporized.


take a inner tube for a motorcycle tractor or whatever and put some diesel on it let it set for a week or so then put it in the sun on a warm day then leave it for a week or so you will see the rubber cracks where the diesel was and also in the first day or so it has a blistering effect aka it expands then its dries out rapidly and cracks / splits. This is what it does to the diaphragm in the mechanical fuel pump and when it cracks / splits it then sucks air and motor oil from the crankcase and pumps diesel into the crankcase its a nasty issue and sadly almost none of the mechanical fuel pumps are rated for or designed for modern diesel fuel just wanted to put that out there parts manufacturers have not found it profitable to update theyre designs / manufacturing procedures for our engines as in theyre eyes our engines are end of life.


mechanical fuel pump failures have wiped out 4 of my motors in past 8yrs and before that I really never had issues again its modern diesel fuel not being compatible with mechanical fuel pumps manufactured for our engines all 4 times was towing heavy and noticed a plume of white smoke then suddenly engine started rattling and oil pressure suddenly dropped to nothing only to find my crankcase was rapidly filled with diesel due to a failed mechanical diesel fuel pump so i run electrical fuel pumps 2 to be exact as a redundancy and to keep fuel pressure fluctuations minimal I keep on top of my motors maintenance with a fine tooth comb and run quality oils / and filters and also monitor my engines across the board EGT's / oil temps / fuel pressure / oil pressure / coolant temps / boost pressures and intake air temps both before and after intercooler.

I’m not opposed to electric pumps, I know they work wonders but, I never have trusted swapping over. My reasoning has always been that the beauty in these engines is the few electronics they have. I had to do a lift pump on mine, did it need it? Well that’s a different story but the old one lasted 27 years loaded almost all it’s life. I’ll keep it simple. Again I’m not downing electric they have advantages. Just food for thought.

FordFlatbed93 said:

I’m not opposed to electric pumps, I know they work wonders but, I never have trusted swapping over. My reasoning has always been that the beauty in these engines is the few electronics they have. I had to do a lift pump on mine, did it need it? Well that’s a different story but the old one lasted 27 years loaded almost all it’s life. I’ll keep it simple. Again I’m not downing electric they have advantages. Just food for thought.

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Could always setup one for backup with a bypass, but I agree about the reliability factor. Sadly I don't think there's a good option for mechanical lifts for high power IDIs