Electric fuel pump on diesel

[BOB_1]

I have read a few posts with people running electric fuel pumps in TD42s to get a bit more out of the mechanical one, Has anybody got any suggestions, comments or confirmed improvements on this?

[DanielS]

Gday BOB,

I have heard about this, and the theory behind it is simple. It provides a constant presure to the mechanical pump- meaning the pump doesn't have to draw the fuel foward, so when you dump your foot theres fuel ready to go.

It also helps in winching situatios where the fuel pump ( mechanical ) may start to draw air.

GQ Trol is the guy to have a talk too, he knows alot about this stuff.

Regards

Daniels

[fnqcairns]

I too have read about it, the added complexity of something else to go wrong hold's me back some.
Does a pump after the filter increase the life of the injector pump any? Sounds possible, cooler injector pump etc???????

Anyone know?

cheers fnq

[DieselBoy]

It has made a HUGE difference to mine.

Way more resposive, improved the fuel economy, rev's out better/maintains power at higher rev's

I have set it up so that if the pump fails, which it won't, all that needs to be done is the dissconnection of an electrical plug and the undoing of two hose clamps to enable a fuel line to be swapped around to by pass the electrical pump.

It has worked mirrcles for my truck, which starved for fuel after the injectors were replaced and set to a higher pressure, the injector pump timing advance right up, the fuel govenor screw tweaked up a little, and the 3" exhaust and intake mods done.

Used a Holly "Blue" pump and Holly pressure regulator.

[BOB_1]

What sort of pressure are you running through it, and is it just a EFI pump plumbed into the line? Is there a risk of damaging seals etc in your pump by introducing high pressures before they are expected to be there?

[fnqcairns]

I too am intersted in what pressure the regulator is set to and is this an N/A engine?

It wont be an efi pump just a low pressure carbie pump -nice and reliable.

cheers fnq

[GQ TROL]

What DanielS and DieselBoy said. We've found it to be most effective on turboed vehicles when used in conjunction with a small surge tank (about 1-1.5L volume). The elec pumps keeps the surge tank full, and injection pump only needs to draw from the surge tank which is mounted somewhere nearby.

[fnqcairns]

GQ TROL is the surge tank used for vehicles without a fuel return line? Would there be any advantage fitting a surge tank to one with a fuel return and a electric pump?

cheers fnq

[GQ TROL]

fnq,
We use surge tanks on turboed TD42 engines, so yeah with fuel return lines. The injector pump has fuel return line as normal, but we fit a t-connection into it from the surge tank so you can bleed (and re-prime) the system in the event that the injector pump sucks the surge tank dry.

[bogged]

fnq,
We use surge tanks on turboed TD42 engines, so yeah with fuel return lines. The injector pump has fuel return line as normal, but we fit a t-connection into it from the surge tank so you can bleed (and re-prime) the system in the event that the injector pump sucks the surge tank dry.

what size surge tank are you using? and custom made or off the shelf?

What brand/model/capacity pumps are you talkin about?

Thanks

[morkz]

i've also heard there is a bloke down in geelong doing wonders to the GQ pumps but its the late model pumps i.e. factory 4.2 gu turbos and hes been able to get more fuel out of them without rebuilding the pump with 12mm rotor unit.

someone GU from down there with a factory pump and 20psi through the turbo simply high flowed is pushing out 166kw at the rear wheels i'm doubting this till i see a dyno report but still this dynoed on 2 seperate dynos be iteresting to find out more on this.

[bogged]

i've also heard there is a bloke down in geelong doing wonders to the GQ pumps but its the late model pumps i.e. factory 4.2 gu turbos and hes been able to get more fuel out of them without rebuilding the pump with 12mm rotor unit.

someone GU from down there with a factory pump and 20psi through the turbo simply high flowed is pushing out 166kw at the rear wheels i'm doubting this till i see a dyno report but still this dynoed on 2 seperate dynos be iteresting to find out more on this.

thats running the 80 series bits in teh GQ pump if Im not mistaken, quite common mod.

[morkz]

actually now... the 12mm rotor and head bit is the 80 series bit which is very common.

But this mod involves no stripping down of the pump which is what is required when fitting the toyo parts (12mm) into the pump.

[xenith]

i have a holley blue pump on my gq no pressure the regulator and no surge tank just in line at main tank eng rev's like petrol now and have out accllrated a feu injected petrol ones to boot

[ozy1]

okay, does anyone have a few more specs on this, as i have a TD42 with DTS turbo, and if i give it a big boot, it powers on, then dies down a touch and launches again,

pump model nummbers, and location people have installed them would be excellent,

[fnqcairns]

Yeah I am convinced also my N/A 4.2 idles near 500rpm lower after around 1000km on a new fuel filter. It also very slightly surges at 55kph just cruising along in 4th.

Can anyone tell me where the relay for the fuel shut off solenoid is on the 4.2td GQs or even better a way to fire up the pump only when the engine starts.

Xeneth you are talking a turbo 4.2?

cheers fnq

[GQ TROL]

Will try to reply in one hit, but if I've forgot to answer something, let me know.

Bruce,
Usually we use whatever we can get our hands on. Have built one from 4” dia aluminium, with flat end caps (with large base plate for mounting to the inner guard), but its usually stainless. For comp trucks, we probably get a bit carried away and make them 1.5-2.0L which means you can run a standard 95L fuel tank only 1/3 full and still avoid surging problems. Its other benefit is during winching up steep embankments when fuel will slop to the rear of your main tank. Having a surge tank of that size means you won’t get fuel starve and get stranded with your PTO driven winch part way up a hill.

Fuel pump is normally a Holley “Blue”…..only needs 8-12 pound of pressure. But these things aren’t cheap, so if someone can find a cheaper source, let us all know.

Morkz,
I think that is probably just mods to the aneroid and governor. Maybe the later model Nissans use a larger plunger element anyway? Haven’t played with a GU yet, would be good to find out.

Ozy1,
That hesitation around 3000rpm is common on turboed engines, and the elec pump typically fixes the problem.

If you want to get really carried away, you could have a crack at replacing your fuel lines with larger dia ones to improve flow too. Haven’t tried it, but it may help.

[DieselBoy]

Pump and Regulator


Handy little spot to hide it




And all mounted in position (not plumbed into fuel system yet though)

[numbnuts]

does anyone know how much these blue pumps are?

[numbnuts]

GQ trol, why when the 4.2 turbo hesitates at about 3000 revs does the electric fuel pump solve the problem?

[ozy1]

what price Can people get the Holley BLue fuel pumps for?

[xenith]

fnqcairns was n/a put large turbo off a 3.0 l vg30 runs 13 psi has over 400 000 km's now still going strong .

numbnuts i have no idea y when i came across this problen this fix was not comenknolage had to work it out my self never did work out the u just the fix
as for price i have used on mates gq a cheaper old clack clack pump off gemini worked as well just put a hose from tank to it . it to fuel line next to tank on reglator

[fnqcairns]

Thanks Xeneth and GQpatrol for the reply's.

When I get to it I will be using a clack clack also, probably one to suit an MQ 2.8 patrol. I suspect one size fit almost all with these pumps.
Thinking I may be able to use th tacho wire to sense rotation and kick the pump into action? Sound feasable - somehow?

cheers fnq

[GQ TROL]

GQ trol, why when the 4.2 turbo hesitates at about 3000 revs does the electric fuel pump solve the problem?

We’re not 100% sure, but this is what we’ve concluded……
The standard Nissan injection pump uses a 10mm dia plunger element, which seems to be adequate for N/A engine. But once the engine is turboed (or even modest performance mods like extractors and intake improvements), the std pump doesn’t flow enough fuel to match the increased air delivery. The electric pump fills the need that the std injection pump cant deliver.

Probably why it isn’t such a problem when turboing a N/A Toyota 1HZ engine, as they’ve got an 11mm dia plunger element as standard and can flow enough fuel without major mods.

[DanielS]

i've also heard there is a bloke down in geelong doing wonders to the GQ pumps but its the late model pumps i.e. factory 4.2 gu turbos and hes been able to get more fuel out of them without rebuilding the pump with 12mm rotor unit.

someone GU from down there with a factory pump and 20psi through the turbo simply high flowed is pushing out 166kw at the rear wheels i'm doubting this till i see a dyno report but still this dynoed on 2 seperate dynos be iteresting to find out more on this.

Morkz, this guy has currently got my pump, I will post figures when it is fitted to the car.

[morkz]

no worries you obviously heard all this from cass....

let me know the results as i might do the same for my shorty pump..... but i was told i needed the late model pump but who knows because i dont think yours is a late model pump either way interested to see the results

[DanielS]

Yeah I did hear it from Cass, I was on the phone to Ray the guy who is doing the work and it sounds like my fuel pump is stuffed I will find out today, might have to get it fully reconded.

Something along the lines of the speedo only saying 100000kms ( 96000 when I brought it from a car yard!!) but the truck has travelled more like 300000kms I when I pulled the bell housing of the to change the clutch it has 262819 written on it also....NOT HAPPY.

But yeah will let you know how I go.

EDIT: My pump is a 96 without the Fuel boost compensator..

Regards

Daniels

[morkz]

oh well you get that....

i reckon my pumps going to need a full rebuild on top of that i need a boost compensator anyway so if your thing doesnt work then i'm forced to rebuild it with 12mm rotor and head unit

[Juzza]

Yeah I did hear it from Cass, I was on the phone to Ray the guy who is doing the work and it sounds like my fuel pump is stuffed I will find out today, might have to get it fully reconded.

Something along the lines of the speedo only saying 100000kms ( 96000 when I brought it from a car yard!!) but the truck has travelled more like 300000kms I when I pulled the bell housing of the to change the clutch it has 262819 written on it also....NOT HAPPY.

But yeah will let you know how I go.

EDIT: My pump is a 96 without the Fuel boost compensator..

Regards




Daniels

do you have this guys full name and number????? Thanks,

[DanielS]

same, if it is going to cost to much thru this guy then I will send it too JPC, hes still makes good power.