well a friend of mine brought his car to my house to wrk on it, ita a 99 civic coupe and they added a ls motor on it, they are getting fuel and spark and sounds like no compression, we checked it and thought that could be the case considering there wasnt, so my friends wanted to at least change the head gasket and got a new timing belt and water pump. they intalled it and said that it turned on real quick then shut off and all it does is back fire, like crazy and still wont turn on, the timing is right and the spark is good, but there saying it sometimes pushes air out through the throttle body, instead of sucking, i dont know it just wont start and just tryin to see if anyone one has an issue like that before..if it makes any sense..

 

bent valves? timing off? have they done a compression test?

 

If air is coming out of the TB rather than going in, something is jacked up in the valvetrain. It's time for a head tear down.

 

Check valve timing.

As mentioned it could be a bent valve, or valves, that would also acount for no compression.

Your post is very hard to understand, "sounds like no compression, we checked it and thought that could be the case considering there wasnt" does that mean you checked compression and there was none???? 94

 

Yeah since he said he heard compression out of his throttle body I would assume the worst and say bent valves by nnow.
I bet they were stomping on the throttlee cranking it trying to get it to start.

 

lol ya there was no compression like it was 30,0,0,60, and ya we r assuming its valves, but wats wierd is that we took off the head and it looks like gas is mixin in with the oil and its not water,lol idk why its doin that but ya there hoping its the valves cause they r gettin fuel,spark and timing looks right but it just doesnt start machine shop here we come, but thanx for yall guys input and tryin to help, greatly appreciate it...