Lift pump to help 1HD-T pump?

[90 Cruiser]

Evening all,

I've a 1990 1HD-T Landcruiser and when on an incline for a short period of time it begins to run a little rough and drop the revs down a bit. I'm told this is not uncommon with injector pumps when they get a little old, more specifically with my model as it has to draw the fuel up.

Have noticed through google searches that some have mentioned installing a low pressure lift pump to get the diesel to the injector pump so that it can do the job its required to do. Some say this rectifies the problem, others say its worth doing either way as it assists performance anyway.

Hoping to hear from anyone who may have done the mod or have working knowledge of it. Am I better of just saving my money for the overhaul when its finally needed? Thanks in advance gents,

Ben

ps Hope this is the correct section, rather than Toyota tech

[marki]

The pump you're after is a Walbro FRB 5, from Flexible Drive agencies (about $190). If you hunt around, you can get 'em cheaper than that (aboult half price) from the US. There are probably cheaper options, but the Walbro is biodiesel compatible.

They work well, and will make a big difference in the situation that you describe - also you never need to mess around with that hand pump if you're changing fuel filters or whatever.

One downside tho' - they're a bit noisy - but you kinda get used to it. Also, you'd better check with your mech that it's not causing overfuelling of your engine, as that can have serious long-term consequences

[dakar61]

Have the fuel filter assy vacuum tested, they develop air leaks around the hand-primer diaphragm. Very common and gives these symptoms.

1HDTs also do this when there is too much play in the pump governor basket and also if the idle damper is not correctly adjusted. Also quite common.

Check these out before bolting something on.

Marki, FYI, an additional feed pump wont alter injection pump output on this type of pump. May have a small effect on transfer pump pressure and therefore dynamic timing, but thats all.

[90 Cruiser]

Thanks for your answers Marki and Dakar. It's going to the diesel specialist for a dyno within on the month so I'll have check it over first. Thanks again for the prompt replies

[trains]

My money is on the hand primer diaphragm that dakar61 mentioned.

T

[Peter @ Aawen4x4]

Basically if your Injector Pump NEEDS a low pressure pump to get fuel up to it, then the Injector pump is pretty sick and really should be fixed - then you wouldn't need the low pressure pump!

Sure, it might help as a band-aid for a problem in the short term as a cheaper option than paying for a recon pump, but it won't really be helping in the power or economy stakes in the long run, and ultimately it'd be far better to get the injector pump recon'ed and maybe a little tweaked while you are at it! Save wasting the money on the low pressure pump too! Altho it might be an idea if you know the injector pump is on it's way out and you just want to sell the vehicle before it dies without spending too much money on it - but no-one here is that shonky, are they??!

Cheers!

[luxxy]

Gday my 1hdt had same probs . 1st changed fuel primer as it was sucking air made small amount of difference . Then had it dynoed and still no good, after talking to a few reputable diesel shops decided that the pump needed rebuilding and injectors too . Was told these pumps need some mods to make them run properly when they get a few k's on them . After talking to many different shops decided to take it to mike green at diesel specialists , hamilton , brisbane . He definetly knows his stuff .The truck has never run better and goes heaps better and use's a lot less fuel . it cost a few dollars but the wife likes to drive it now.

[marki]

I've got an update - I found a better pump than the Walbro, a Posi-Flow pump from vegiecars.com. At $140 it's cheaper than the Walbro, and is a lot quieter.

Even if your car doesn't strictly speaking need a lift pump, it means that you'll never ever be messing around with that silly hand pump again