I am working on a 1999 CRV (B20Z) that originally had a misfire on all 4 cylinders and occasional blinking CEL. I adjusted the valves and now I just have a misfire on #4 (p0304). Did a compression check and #4 is only hitting 70-80 psi. (1-3 are good)

Is there any sense in rechecking the valve lash on #4? or does the comp check mean its beyond being out of adjustment?

Next:
I have a strong OBD1 B18B1 sitting on a pallet. Would it make sense to swap the head from that onto the B20 if the valves are toast?

 

I went ahead and rechecked the valve lash. It was good and the compression in #4 is still 70-80 psi. Next I'm going to pull the head and see how much it will cost to have the valves repaired. It's probably worth rebuilding that head anyway.

My answer to my own question about swapping on B18B1 head is that it should work fine using a B20B head gasket. The heads are pretty much the same, but the cams from the B20 should go in it. - I won't be doing that unless I don't like the cost of rebuilding the B20 head.

 

The heads are identical.

Put a little oil in #4 cylinder and try the test again. No sense in doing all that work to the head if the rings broke.

 

Just a little follow-up (I hate when other people's threads end without a conclusion):
It was confirmed as a bad exhaust valve when I pulled the head. In the picture you can see a small notch in the valve where I am pointing with the orange scraper.



While I have it off I am having all the valves checked/repaired, replacing all the seals/gaskets/grommets, and putting on a new timing belt.

 

I barely bought my crv and had the same problem, I had a burnt exhaust valve, it was missing a good chunk. I just bought a jdm b20 head off some guy that did a b20/vtec for a measly $70 bucks. Now the crv is running likea champ.

Good luck fixing up your crv.

 

I finally got it all back together and running. The head work was verbally quoted at around $275, came out to $375 with all new seals, exhaust valves, and a resurface. Add in the head gasket set and the timing belt kit and d@mn... I could have just spent it on a JDM swap. At least I know the head and timing belt are all fresh now.

 

the JDM swap is still going to be ~900-1000 after shipping. then you still have to replace all the belts/wires/plugs etc. sigh I've spent a lot of money.