changing from efi to carby

[pix35 1]

 

hey all

 

thinking about changing my 250crossflow from efi to carby and im just wondering how hard it will be to do..is there a lot that i will need to change?

 

any help would be great

 

cheers

[unfamilia 1,938]

Why???? Efi would be more power and drive ability wouldnt it?

 

Put I do love the sound of carbies on full song too

[Mr Polson 10,214]

Pretty much unbolt EFI manifold, bolt on carby one.

Change dizzy I think.

Have to change or restrict the fuel pump too, and fiddle with a few fuel lines.

Different accelerator and kickdown (if auto) cables.

 

Might be a few things more, I'm not sure.

[pix35 1]

cheers mate. that helps a lot. still unsure what i wanna do with it yet.. do u know how much power u can put into an efi before changing the throttle

 

Pretty much unbolt EFI manifold, bolt on carby one.
Change dizzy I think.
Have to change or restrict the fuel pump too, and fiddle with a few fuel lines.
Different accelerator and kickdown (if auto) cables.

Might be a few things more, I'm not sure.

[XPT 673]

If you are wanting to do this for more power and tunability. You could instead look into changing to an ea or eb1 mpefi ecu and then tune with a J3 chip. That way you could do away with the standard afm and run the MAP and AIT sensors from the E series, this would also give control of ignition and fuel. You already have most of the parts on the car to do it, efi fuel pump & relay, injectors, throttle body & TPS, TFI dizzy, 02 sensor ( if unleaded). I think you would just need the MAP and AIT sensors from the e series. I know It has been done before. They are very similar in layout. It seems like a lot of work to change to carby for no gains. Just an alternative for you.

[KRUPTOR 929]

I did this conversion to my xe which was a efi 4.1,i had trouble with the wiring being badly corroded.I fitted a xf intake and weber carb,and fitted a solid state low pressure fuel pump.Didnt change dizzy as its an early xe.

[Mr Polson 10,214]

cheers mate. that helps a lot. still unsure what i wanna do with it yet.. do u know how much power u can put into an efi before changing the throttle

 

Wouldn't have a clue to be honest, I haven't played much with my EFI xflow, I just made mine look pretty. 

 

 

 

If you are wanting to do this for more power and tunability. You could instead look into changing to an ea or eb1 mpefi ecu and then tune with a J3 chip. That way you could do away with the standard afm and run the MAP and AIT sensors from the E series, this would also give control of ignition and fuel. You already have most of the parts on the car to do it, efi fuel pump & relay, injectors, throttle body & TPS, TFI dizzy, 02 sensor ( if unleaded). I think you would just need the MAP and AIT sensors from the e series. I know It has been done before. They are very similar in layout. It seems like a lot of work to change to carby for no gains. Just an alternative for you.

 

XF EFI never had O2 sensors, regardless of leaded or unleaded motor. The unleaded motors gained a knock sensor on the cylinder head.

[Scottee XDFwreck 42]

The EFI cam shaft doesn't have a lobe for a manual fuel pump, i removed the in tank pump & replaced it with a length of hose. Fitted up a holley red fuel pump, they are allready set at 6 psi, perfect for a webber or holley or the holley blue has a regulator.

I fitted an after market manifold with a 2 barrel holley, fitted an XE V8 accelerator cable,

I made up a short harness (5 core trailer harness!) that went from the factory EFI connector near the brake booster over to the manifold area. XE dizzy & coil which was only 2 wires, oil pressure light (& guage) & temp.

The best part with this set up is i didnt chop or modifie anything, I wanted to go back to EFI later, which i did when i eventually sold that car, which is the red XF GHIA in my avator.

[revhead 1,392]

easy job ,do what everyone said ,just unplug the fuel pump in the tank ,so it doesnt work at all ,and fit a 4pound low pressure pump from repco into the engine bay ,just for your own info the efi dont wont have a fuel pump drive on the cam ,cheers have fun chuck up some pictures for us

[unfamilia 1,938]

So a facett pump is fine in the engine bay. I thought better in the rear as they push better than they pull fuel.

[XPT 673]

XF EFI never had O2 sensors, regardless of leaded or unleaded motor. The unleaded motors gained a knock sensor on the cylinder head.

Fair enough, I have only seen the leaded efi motor. Just assumed they would have O2 for unleaded, my mistake should have confirmed. Regardless of this they are very similar.

[Scottee XDFwreck 42]

I started with a facet pump in the engine bay & it struggled to keep the holley float bowl full, so i hooked it up in the boot & was heaps better but still no good at high revs.

6 psi  is all you need & a holley can handle

[pix35 1]

so i have spoken to few engine builders and few other people and have decide to go carby. just need to get a 4 barrel manifold and a 465 holly carby. and of cause getting my engine complete rebuild. so will get photos as im doin it and hoppfully it turns out good

[Ando81 2,949]

A fella is selling an aussiespeed 4 barrel manifold to suit a crossy in the wreckers section for $300. Pretty fair price considering they are upwards of $450 new.