265 Hemi to efi

[heff0018]

Just an update, I checked the fuel pressure gauge and at key on ignition it drops to zero fuel pressure 15 seconds after initial prime. That can’t be good.

[vlad01]

Bad check valve in the pump I'd say, I had this happen for years about 10 years ago with multiple pumps all failing their check valves. Was bad fuel coming from all the BP servos at the time.

Now it seems I haven't had that issue for many years already after their sorted their crap. Their 91/E10 are all yellow now. Back then, it was that pink/red colour and that seemed to be the stuff that was killing everything with it's fine smoke/soot like red/purple dust coating and blocking every fuel component.

But I digress, have a look at the pump and in the tank for crap that might possibly be causing issues with the pumps internal check valve. You can check it by back pressurising with compressed air, if air/fuel comes back out the pump in the wrong direct, that valve is shot.

You can even do it while it's still in the tank, you'll hear it bubbling in the tank if the valve is bad.

[heff0018]

Great thanks Vlad, I will do that test next. It’s been sitting for years so not surprising that there would be fuel issues. I did drain the tank years ago but not the surge tank or pumps. I probably should replace the lift pump and high pressure pumps for good measure as they have sat for so long.

[Charlescrown]

Easy way to find out where the pressure drops is to get a set of hose crimp off pliers and start and run the engine, switch it off and quickley clamp off the suppply hose and see if it holds pressure. If it still drops repeat the test and lamp off the return hose. If it still drops you have leaky injectors. Sounds like you have a complicated fuel supply system. I swapped over to a Holley intank unit a few years ago simple and effective.

[heff0018]

Thanks Charles, yes of course. Hadn’t thought of that but makes sense.

I would have converted my system to intank pumps years ago but there is not much room under the ute tray and most conversions I have seen are top mounted.

[Charlescrown]

That was a minor issue with mine but I did get it to fit. Missed adding if the pressure still drops after clamping supply and return lines it can also be the fuel pressure reg diaphragm leaking. Ths should also show up when you pull the vacuum hose off it will have petrol in it.

[heff0018]

Thanks for the update, I was thinking that it could possibly be the regulator and will check for fuel in the vacuum hose.

[delcowizzid]

A lot of aftermarket pumps drain back straight away it's not normally an issue

[heff0018]

I clamped off the fuel line to the rail and no difference, i clamped off the return line out of the Aeroflow regulator and it finally held pressure.

[vlad01]

Fuel reg?