ALH lift pump install how to?

Blacktree said:

Please excuse the noobish question, but what's the reason for retrofitting a lift pump to an ALH? Is it to support engine mods?

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I know this is an old post don't beat me up...

Just a couple other good reasons for adding a lift pump would be to make fuel system priming a lot easier after running out of fuel or changing a fuel filter, and it takes load off the transfer pump in the IP. I am strongly considering installing one for those reasons.

Yes and it also makes cold weather starting easier. My girl almost jumps to life.

I have always thought of this as a push / pull relationship in the ALH. Nothing like making the movement of fuel an easy bit of work with the in tank pump pushing and the lift in the IP pulling at the same time. Can't believe they did not implement this earlier as an OEM setup in the ALH.

kiwibru said:

Can't believe they did not implement this earlier as an OEM setup in the ALH.

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"Parts left out cost nothing, and cause no service problems".

Charles Kettering, Head of Research at GM 1920-1947, inventor of the starter motor, leaded gasoline, and Freon-based air conditioning.

It also helps people with extensively modified engines to keep fueling their motor at higher RPM ranges. That's one of the reasons my wagon has a lift pump.

So now I'm curious. At what horse power point is a lift pump a good idea? At what point is it necessary to add a lift pump to prevent hp loss at higher rpms?

Personally, I wouldn't say that there's a figure, but it's more about the engine build. Mine is built to spin up much more than a stock ALH and is capable of higher RPMs. It'd be required to run more fuel at higher RPM to keep producing power past 5000 RPM. If you build it extensively with a built head, an aftermarket cam, valves, valve springs and all that good stuff, then I would say it's helpful. But, you can also do it for easier startups, easier priming of those pesky fuel filters and such.

LNXGUY said:

30 - Fuel pump
87 - Battery 12V
86 - Signal wire from Injection pump
85 - Ground.

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Is what you say coming from an existing relay or obtaining another relay being used specifically for this job?

In the small relay box next to the brake booster there is an empty relay socket that you wire all that into.

LNXGUY said:

30 - Fuel pump
87 - Battery 12V
86 - Signal wire from Injection pump
85 - Ground.

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What wire is signal wire On alh injector pump ?

The picture of the relay has a description next to it... "Fuel cut-off on pump(signal wire)" which is the wire on the top of the pump head just before where the metal injector lines come out.

jhax said:

The picture of the relay has a description next to it... "Fuel cut-off on pump(signal wire)" which is the wire on the top of the pump head just before where the metal injector lines come out.

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Do you have a picture of yours ?
this is the first time and I don’t wanna **** it up already got stranded 3 hours from home waiting on side of road for 2 hours

It is the black wire at the top of the back of the pump in the picture, very hard to miss https://www.myturbodiesel.com/d2/images/a4/TB_head_rem/ip30.jpg

Thank you sir I’ll try that

Follow the schematic it is easy to wire it up

Does everyone do the in tank pd pump or are there guys running inline fuel pumps? I was going to install a inline pump from a 6.5L gmc diesel under the hood (push/pull pump rated for 32gph) they are cheap and plentiful. I guess they probably don't flow as much as the vein style pump, but when you compare to the factory no lift pump it should still be a improvement.

derek5120 said:

Does everyone do the in tank pd pump or are there guys running inline fuel pumps? I was going to install a inline pump from a 6.5L gmc diesel under the hood (push/pull pump rated for 32gph) they are cheap and plentiful. I guess they probably don't flow as much as the vein style pump, but when you compare to the factory no lift pump it should still be a improvement.

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I did the intank lift pump only because I did a alh swap to a clean bew wagon

"Does everyone do the in tank pd pump or are there guys running inline fuel pumps? I was going to install a inline pump from a 6.5L gmc diesel under the hood (push/pull pump rated for 32gph) they are cheap and plentiful. I guess they probably don't flow as much as the vein style pump, but when you compare to the factory no lift pump it should still be a improvement." dereks5120

Similar situation that I have installed in my Jeep "05 Liberty CRD. The PO had simply installed a $25 inline pump,
the VM motor as it ages has a tendency to lose prime. He did point it out when we went over the car. It did die, and yes, the car stopped unexpectedly a couple of times. The Jeep has a hand primable fuel filter, so it didn't take much to get it going again. Replaced the pump, judging from the POs receipts, about 5yrs old. No more problems.

The "proper fix", at least as espoused on the Jeep forums, is an intank lift pump. After dropping the tank, and going through fairly extensive procedures, a solid 4-5hr job, and >$300 with the right harness. Took me mebbe half an hour
on the Rhino ramps, one side, a couple of crimps and plugging some hoses back on, <$30, to put a new inline pump in. And I'm a slooow mechanic.

With the amount of fuel needed to assist the fuel pump, even at high power and revs, I suspect it won't make a bit of difference to the motor if you go a small inline pump.

I share what I haven't found here, to help:

The professional tuners says that a lift pump could help but not necessary. There are 300+HP cars without liftpump, you need a good VE Pump and fuel system.

-If the lift pump is underscaled, it becomes a rough resistance in the system at high revs. The VE has a very good pump, it can easily achieve 0.6-0.7bar of vacuum, then it sucks air into the system everywhere. The result is sky-high EGT and melted turbo about <10sec because the preload adjuster piston cannot work in a system which contains air. (if you don't have an EGT gauge you realize only the lack of boost, because the doses don't decrease despite the vacuum)

-don't use high pressure pump (e.g. gasoline pumps) because the positive pressure on inlet side of VE pump is also a resistance for the preload adjuster (or timing) piston.

To scale the fuel system (estimation):
ca. 0.5 l/min needed in every 100 HP and 0,5l/min for backflow (independent to HP)
With lift pump the pressure must be +0.3 to 0.8bar at idle and +0.1bar to 0.2bar at max load.
(without lift pump you need proper filters and larger pipes to keep the vacuum under 0.3bar)

-the story have to be ended with controlling what you have done...

And Laszlo, one does not want to overpressurize the IP as the front seal can get driven out. At least the fuel will just leak out instead of commencing a dilution of the crank case oil that the gear-driven Cummins-es suffer. Going to have to do this on my ALH; if only to make fuel filter changes simpler...

The Carter 4601 is a diesel-rated pump that puts out about 8 psi. Loud, but bomb-proof.
cheers,
Douglas

If you have (had) an auto like me the small relay box next to the vacuum booster is missing. But you can get that plus some used relays, wiring, and relay plugs off of ebay and retrofit…. I have my lift pump and HID ballast relays in there.

PakProtector said:

And Laszlo, one does not want to overpressurize the IP as the front seal can get driven out. At least the fuel will just leak out instead of commencing a dilution of the crank case oil that the gear-driven Cummins-es suffer. Going to have to do this on my ALH; if only to make fuel filter changes simpler...

The Carter 4601 is a diesel-rated pump that puts out about 8 psi. Loud, but bomb-proof.
cheers,
Douglas

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Are you installing this Carter pump on your TDI?

J_dude said:

Are you installing this Carter pump on your TDI?

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nope, I put one in my D250...much higher noise floor...

Douglas