2.3L ('83-'97) 94 Mazda b2300 Weird idle

[E.B.N.S]

Hello I recently got a b2300 for what I thought was a good deal I bought it with the weird idle thinking it was a simple IAC valve. I was wrong though lol. The few things I've tested has a been replacing the iac valve, cleaning the maf sensor (which was slightly dirty) and I've tested for vacuum leaks with my harbor freight vacuum tester. I get like 16-17 HG in vacuum pressure on some forums people say that's normal and some say it's not. My next test I think is going to be testing compression I'm afraid I have a blow head gasket or some bad piston ring which the truck does produce alot of white smoke for a while after a cold start. Does any one have any advice or tips?

 

[franklin2]

Keep going. Checking the mechanical condition of the engine with the compression check is a good idea.

 

[SenorNoob]

IIRC motion of the needle on a vacuum gauge tells you as much as the reading. Is it steady or twitching?

 

[E.B.N.S]

To answer @SenorNoob the vaccum is steady. Aswell as most important I done a compression test and 3 cylinders are low
Cylinder 1 =120
Cylinder 2 =130
Cylinder 3 =160
Cylinder 4 =125
So with this information I guess next step would be pulling the engine. It will be a month or so before I do that because this is my only vechcle at the moment.

 

[franklin2]

Squirt oil in those low cylinders and see if the compression numbers come up. If they do, rings. If they don't, valve sealing problems in the cylinder head.