i recently picked up a 1990 civic dx 4dr. . .the car originally had a bad headgasket. . .when i brought it home it was missing a main relay. . .i installed one and when i attempted to start it up it turned over and backfired through the intake almost like the timing was off. . .but i checked it over and over again. . .so i just went ahead and replaced the headgasket and timing belt. . .and once again when i got it all done and tried to start it, it would turn over and still backfire through the intake. . .the valve seemed to be fine when i had the head off and everything else looked ok. . .there is no check engine light on anything. . .Somebody help please!!!

 

does it start and run at all? if not take the distributor cap off and check the rotor and see if the little bolt fell out of it. if not check the distributor itself.

 

Ignition timing isn't likely the problem. Be absolutely certain the valve timing is correct and I don't necessarily mean to set it where it was when you got the car. If the timing is on then you probably need a valve job. With the head off, you can check how well the valves are seating by standing with the head in a dark room. Hold a flashlight against the bottom of the head while looking into the intake ports. If you see light coming through the valve openings then they aren't seating well. Check the valves of each cylinder in this manner. Also, check your exhaust for major restrictions. A plugged exhaust can exacerbate a valve problem. It may even be that a valve problem was misdiagnosed as a blown HG.

 

your problem could be backwards injector wires

or you timed on the wrong stroke, thats the only reason you would have this problem

if you did need a valve adjestment, you still would get the motor to start, but with some loud TICKING.

 

I had a similar problem with a fully built engine and it has to do with bad gas which seized up my valves so they didnt close good so try cleaning ur entire intake system cheaply brake cleaner toothbrush and time and changed the oil after u get it 2 run or remove head and get a valve job if it is sticky vales keep investigating do a compresion test