Advice needed on my 90 4.0 OHV

[Isaac97412]

Hi guys this is my first post, though I’ve been looking at this site for years for my ranger. My ranger recently overheated and I cracked both cylinder heads so I bought new pre assembled ones and installed them with new gaskets. Failed to start. Checked compression and I’m getting about 100 psi per cylinder. Someone told me the timing sounded off but I’m unsure of how that would have been affected as I didn’t mess with the chain. I can’t figure out how to attach a video for you guys for show. Getting spark, fuel. When I crank it over it sounds like it almost wants to start and I’ll get a backfire and flame out of throttle body along with a hiss noise. Need help asap, thanks

 

[bobbywalter]

are you sure you have the right heads?

were they decked? what about the block?

did you measure the pushrods? are the pushrods rockers and lifters new??? these valve trains are easy to get janked up once you start mixing and matching.

assume this is a 90 and it is bank fire and no cam sensor. 100 psi cold and dry seems livable to start.