what all has to be done to put a 90 Integra b18a engine in a 99 honda crv

 

A b20 can be picked up for pretty cheap, I wouldn't bother to be honest.

 

I havnt been able to find a cheap b20 in my area and I already have the b18a and trying to save money

 

If you have the original engine swap over injectors, alternator and distributor. You'll have to bypass the CKF (search for CKF bypass). You'll also have to wire the fan switch from the thermostat housing to the back of the block. Youll probably need to swap over the exhaust manifold from the CRV. You may also need to swap over the fuel rail from the B20. The transmission will bolt up. You should be able to use the mounts but you probably have to swap over the B20 timing belt mount (the one bolted to the block) over to the B18. You'll also need to swap over the B20 throttle body to the B18 as it has the MAP sensor on it. The knock sensor is going to be tricky as the B18 doesn't have a spot for it so you'll have to tap a block location. Like I said it's not a fun swap and a JDM replacement would be much easier.