fuel pump woe's in 1uzange rover combo.

[zen]

see this is hurting my head.... (1uz fe in 2 door old range rover..recent swap all legal and on the road..)

have been dining some research now little one has hit the pillow..

what i have is carby tank..v8 lexus engine..fuel goes via rangie lecky fuel pump by rear arch..then to inner wing mounted standard (carby)fuel filter (all 8mm pipe)(new)..to swirl pot (s.p.)on inner wing (has 4 connections, goes to 2nd from top)..then (from bottom connector on s.p.) to brand new (no 2!) bosch inj pump..to hp filter (horizontal mounted)..to engine...return from engine to s.p. (3rd connection from top)..return to tank is via standard return pipe on rangie (6mm)..

now research says this is good..but i get real bad hp pump noise (rangie lecky pump ticking away at a very quick rate too)..then after a while it stalls (30mins or so)..leave it a while it will restart but stil with real bad noise...WILL give the same symptons even on gas (EXCEPT FOR STALLING!) ..

now why is it doing this?i dont want to redesign fuel sytem if its just something stupid.

could it be return pipe not enough diameter? cant see this...

could it be air getting in somehow? maybe but from where, no loose connections that i can find...besides it should all be vented via top of s.p. to return to tank..

could it be petrol vaour build up?? maybe, but again it should all go to tank via return..unless its getting traped in the sytem somehow..the filter is on the outlet so it cant be there...

the rangie lecky lift pump not doing its job??maybe, but there seems to be enough feeding to s.p.

could it be tank not vented proper (vac build up)..dought that, i did the tank install and besides has original tank cap (read leaky)


could it be rubbish in tank....just blocking up filter on sucky up pipe in tank??maybe..?

to recap..hp pump gets increasingly noisey, lecky lift pump gets faster too (very fast)..car stops..restarts after awhile..ACTUALLY seems to be better with engine on power rather than than in traffic..

its doing my head in...i have a lovely 2 door outside with a 300hp quad cam v8 in i cant use (wont start on gas,)i cant afford a new tank etc just yet, anyway everywhere is shut..


suspose i can rig up a temp relay to shut off hp fuel pump once on gas,(so can start on petrol and switch to gas,) but at £100 a pop for cosworth hp pumps that last an hour i would rather get it sorted proper!!(on number 2 now, and thats now making horrible noises

)

help and thoughts please.

 

[gloverman]

If running on Gas then I recommend turning off the petrol pumps. Have you checked your voltage to both the fuel pumps? and the fuel flow and pressure from each of the pumps? Low pressure pump needs to flow as much petrol as the motor can use when worked the hardest. I usually aim for about 120 litres/hour. High pressure pump needs to flow the same but at about 3bar(45psi) Surge tank should have no pressure in it when running as there should be no flow resriction back to the tank.
Another option that I use is to fit a EFI pump into the fuel tank and make it really simple. We have done this to heaps of hilux and surf and it works perfectly and reduces the fuel pump noise. A universal 38mm pump or even a walbro (correct spec for v8) will work well.

Cheers

 

[Zuffen]

My inclination would be to source a Rangie EFI tank and use the RR pump in the tank.

That would be cheaper than buying the EFI pump in the beginning.

That gets rid of the swirl pot and simplifies the set up.

I can't see any problems in your layout but if two EFI pumps have failed something is seriously wrong.

I would guess the stock carby pump isn't up to the job and the swirl pot eventually empties and the EFI pump flogs itself to death on a nice mix of fuel and fumes.

EFI pumps need to kept full of fuel to survive.

 

[zen]

welll we will see..i agree with should have just have fitted the efi tank (espically when it was a rolling chassis!hind sight is great eh??

i expect on thinking about this last night that the return is too restrictive, and prehaps the low pressure filter is blocked..if i get the chance to go to work later i will investigate..

in the new year an efi tank (with internal pump) is the answer i think, till then though i would like to use it, so investigate i will (besides i need to know why its doing this, not just fix it)

 

[zen]

well i now know..

150psi air line soon sorted it...added 2 extra clear filters ,1 in return, 1 in feed to low pressure pump, did this to see whats happening (and as i expect i removed gauze filter from pick up pipe in tank..150psi! to protect the lp pump)

part blocked return and feed from tank..

i still think the return is too small bore (6mm)

goes like stink now!and the pump is now at a nominal noise level,connected back up to full voltage (controlled via ecu)

efi tank and pump first thing on shopping list after new year..

 

[zen]

for the record..

now has efi tank with built in pump..dumped the hp fuel pump, lift pump and swirl pot..

now nice and quiet and removed alot of potential fire starting pipework/fuel elements from engine bay..

 

[Zuffen]

So Santa arrived late but all is well.

 

[zen]

yes indeed...

getting there, still running into a few probs as i use the car...lt95 gearbox has toooooo go!5 speed in place i thinks,far tooo a slow gearchange as is, and i keep forgetting to disengage the overdrive..

nice amout of power though, spins all wheels nicely

 

[Zuffen]

Be aware the LT77 is going to struggle to handle the torque of the 1UZ.

My LT77 died after around 5,000k's.

The Santana may be better (a bit) but getting one will be the problem.

My choice would be a Toyota 5 speed with right drop transfer.

You would lose full time 4x4 but I haven't noticed any issues with that.

You could graft an LT320 transfer to another 5 speed box?