IHZ's - are they all the same? (1 Viewer)

[sunrk]

ie. can any 1hz be swapped for any other 1hz?

Are there any design differences on the later 1hz's (such as the ones Toyota still makes for 79's in some markets) compared to really early ones like the 1hz in my 80 from the factory in march 1992?

 

[mudgudgeon]

Yes they can be swapped.

No they aren't all the same.

105 series (98 onwards) use different pistons. And have immobiliser system on the pump (fuel cut solenoid).

There's differences in cooling lines / ports in the head too.

There's other minor changes to pumps, injectors, timing belt tensioners, intake air hose, air boxes etc

Probably a bunch of other improvements, refinements, or production efficiencies that have crept in