1hd-t vs 1hz injection timing

[80's_delirious]

Ill try and make a long story short, my 1hd-t injection pump shit itself and I dont want to spend the money to fix it at the moment.
I was given a 1HZ pump(history unknown) which I thought I would fit to see if it would get my truck running again.

I have fitted up the 1hz pump and fired it up. When I first started it, it ran very rough, would barely idle and was chugging out heaps of grey/white fuely smoke.

After having a think about it I figured 1HZ timing would be more advanced due to indirect injection, so I adjusted the timing screw on the pump to see if it would make any difference. I have adjusted it as far as possible and it has definitely helped, it is far less smokey and is running a lot crisper, smoke is now grey/black, but still to smokey to run it as it is.

My question is, what is the injection timing of 1hd-t and 1hz? I believe the timing for a 1hd-t is 4deg before TDC. What is it on a 1hz?

how many degrees of advance/retard adjustment can I expect using the screw on the pump? Will I get more or a larger increment of adjustment by rotating the pump body?

[Dzltec]

You will need to set static timing first, then put your advance screw back where it was. Plunger lifts between the two are quite a bit different as they use different cam plates.

Timing spec for 1hz is 1.03-1.09mm @ tdc, 1hdt is 1.29-1.35mm @ tdc


Andy

[80's_delirious]

thanks Andy. I think I set the timing at 1.29-1.35 (it was a while ago) is this still going to be relevant with the 1hz pump in use on a 1hd-t ?

sounds like maybe I should set it at 1.03-1.09?