Outer Limits 4x4 Board

I bought a HZJ75 troopy last august, it's a 92 model. From word go the 1HZ [natural] has flat spotted beteen 2500-3500rpm, give or take a couple of rpms. When i say flat spot, i mean it's like you lift your foot off the accelerator pedal, & on again, off, on, off, on, until you either drive out of it or accually lift your foot, then accelerate again. It's nearly like it momentarily gets a gut full of air. Be it some what of an intermitant problem, it's making it quiet difficult to pin point. Funnly enough prior to purchasing the troopy, I test drove a couple of others which also presented the same symptoms. I don't know, i could be wrong but i half suspect the governor to be a problem[stabbing in the dark here].
If anybody has had the same problem,PLEASE PLEASE PLEASE ANY ADVICE WOULD BE GREATLY APPRECIATED.

Funny that i currently have a turbo intercooled 1hz and only when i first start it up and go down the street and i feed it the fat it sumtimes does that just a lil bit like it is starving for fuel. maybe check ya injecters and run a bit of aditive that mite help but dont hold me 2 it.

Two things It could be matey...

Govenor diaphragm wears out fairly quickly and when that goes - it unsettles the pump and hence a flat spot. The other being a bit of muck in your pick ups in the tank - rip em out and get a toothbrush onto them!

I've suffered from this and teh tank had a great amount of hairy gunge on the pickup ruining my days..

have fun!

You will find something wrong with fuel supply, either rubbish on the inlet filter in the tank/fuel filter, or worse....algai....if you really want to get the power out of the turbo, fit an electric fuel pump after the solenoids, and use it to circulate the fuel through the filter/s so the diesel pump doesnt have to suck it up......when its available like that, the diesel pump will put 100% in at all engine revs.....and the timing will be precise.
Plenty have done it on lcool.org, and they are all amazed at the difference
Andrew

check the easy stuff first, change the fuel fiilter and get the injectors checked and serviced if required. If the motor has fairly high km (200k+) it is likely there is a little wear in the fuel pump and it will benefit from an electric lift pump back at the tank to maintain the fuel flow up to the injection pump.

80diesel4play, any chance of u can give me some more specific details about the governor diaphram that u mentioned, i'm very curious to find out more. I realise i can go talk to some diesel injection specialists, but i'm just trying to do a little homework first. By all means thank u very much to those that have replied so far[cheerz].

Flat spotting in a 1hz engine is caused by lack of fuel, check for fuel restrictions, sucking air, block filters etc. The pump has no diaphragm in it. If you have checked all the basics and they are ok, then there may be a fault with the pump. You can always hook a 4litre container of fuel to the pump to see if it goes away.

cheers

Hey guys i was just at the dyno shop on sat and i mentioned bout this flat spoting and he said straight up that the 1hz pumps do this when the pump is just bout stuffed (wearing out) he said the 1hz pumps are well known for this so it dont lok good bud. I just got mine done a few months back and it cost me 2grand.

tuff 75 wrote:Hey guys i was just at the dyno shop on sat and i mentioned bout this flat spoting and he said straight up that the 1hz pumps do this when the pump is just bout stuffed (wearing out) he said the 1hz pumps are well known for this so it dont lok good bud. I just got mine done a few months back and it cost me 2grand.

go the electric lift pump. if you paid $2k to have your pump rebuilt a few months ago (a) you were raped (b) it should still be under warranty, take it back and get them to fix the problem.

i got compensator and the lifters in the pump largend so i can pump more fuel, Champmans at coory done it........... icleaned the lines and it had shit in the pick up line

tuff 75 wrote:Hey guys i was just at the dyno shop on sat and i mentioned bout this flat spoting and he said straight up that the 1hz pumps do this when the pump is just bout stuffed (wearing out) he said the 1hz pumps are well known for this so it dont lok good bud. I just got mine done a few months back and it cost me 2grand.

I had one done last week and it cost $1500. The shop told me the same thing about 1HZ pumps crapping out at under 200k.

They are available in limited numbers from Ballarat Toyota for $1750 new OEM. Wish I had have seen it 1st

Thank u all very much for your advice,experiences & enquires on my behalf.Any recomendations about brands & flow rate specs on electric pumps for future reference would b great also. I think from what your all telling me it would b a valuable addition before &/or after i get the pump checked out to fit one. And any advice on fitment for this device 2 please. Thanks again to all concerned, hope to bump into a few of u around the traps one day.