Nissan R2

franc123, Jan 2, 5:53am
I'd be compression testing it before doing anything else. If its all been timed up by the book it seems a bit suss that its now down on power. Any sort of overheating quickly leads to loss of ring tension and even cracked liners on those things. If it ain't squeezing that air hard enough it ain't gonna perform. I assume also that the injectors were tested while they were out for good spray pattern and pressure, they don't much like overheating either.

fryan1962, Jan 3, 11:45am
Injectors were not tested he is old guy limited budget. I think it could be rings

skull, Jan 3, 7:08pm
Is it possible that the head is not exactly the same as the one removed! I would expect to see a bit more smoke than before if it had bad rings or cracked liners, should be heaps of blow by if you rev it up with the oil filler cap off too. If you have lost power compared to how much you had immediately before the head was removed then you need to look at the bits you have worked on. If it had lost the power before the head was removed then you need to look at what you haven't done.

fryan1962, Dec 30, 9:06pm
My uncle has a 1996 diesel truck,he blew the head gasket and cracked the head
He bought replacement head bare, lapped valves,new air cleaner,new diesel filter
Timed on the marks,it starts run well, but it does not have top end speed thatit is used too and gutless as well
he has adjusted diesel pump timing nothing he has tried has worked any ideas
so new top end starts well idles well revs well

fryan1962, Dec 30, 9:21pm
top 75 to 80 klm

johnf_456, Dec 30, 9:31pm
Blocked exhaust!

fryan1962, Dec 30, 9:38pm
John good it had an auto exhaust brake he has opened it permanently now

johnf_456, Dec 30, 9:45pm
When it gets in the 75 to 80km range what does it do specifically, sits there running normal! coughing! any unusual noises! smoke if so what colour! Is it get upto operating temp!

fryan1962, Dec 30, 11:15pm
Runs normally just no power.not that they are the most powerful
yes checked throttle is pulling full stroke

mugenb20b, Dec 30, 11:21pm
R2 is a Mazda engine. But, anyway, has the vehicle been parked up for a long time! If so, sticky brakes maybe! Rag left in the air intake!

fryan1962, Dec 31, 2:03am
It is a used model from Japan. It has a Mazda engine and a Nissan body

it revs freely,he has coasted in it and it seems to roll ok