1hz/1hdt fuel pump

[dickie75]

g'day got a 75series 1hz with dts turbo kit.
wondering if the 1hdt pump with boost compensator would bolt straight up as my pump is leaky. and if anyone knows a good mob to get my hands on one?

[drr]

You can just add the boost compensator off the 1hd pump, it just replaces the standard atmospheric compensator. But yes, the whole pump will bolt straight on. The blocks are nearly identical (turbo oil feed gallery is the biggest difference)

[80's_delirious]

yes it will bolt up. BUT they are different.

I tried to do the opposite, I fitted a 1HZ pump to a 1HD-T to try and keep it on the road temporarily. It bolted up no worries, but I couldnt get it running well enough to be driveable. The injection timing is different, among other things. If you have access to 1hd-t pump, it might be worth the experiment.

second hand 1hd-t pumps are hard to come by, and a reco pump will set you back well over $2k without a second hand exchange unit.

[drr]

The timing and setup is different due to the cam disc profile (the 1HD is direct injected using 2 stage injectors, 1HZ using 'dumb' single stage non-direct injection). I didn't think of that at first. The pump will need to match the injectors, or at least be somewhat similar. Easiest just to use the boost compensator off the 1HD on the 1HZ pump. Then play around with max fuel delivery. Keep in mind the adjustment on the boost compensator is a cam type adjustment screw. It needs to sit at a certain position rather than being wound right in or out, it only has a 360 degree adjustment range, then it goes back to the minimum setting. I hope I have explained that reasonably.