So I am stumped...have a 1993 prelude vtec with an OBD1 P13 computer running an h22a1 engine. Everything is stock with the exception of a manual tensioner on the timing belt. Car was running completely fine. Took it for a drive a few days ago, an hour later went to start it to put it in the garage for the night and it would only cough and sputter. Got it to a point where it will start up now after some patient coaxing, but is running extremely rough, missing, and blowing air back out of the intake with absolutely zero throttle response. Compression is 180-190 on all 4 cylinders. Tried a new map sensor, new coil, new injector resistor box, has fuel pressure at the rail, have spark and put on all new plugs wires and dizzy cap. Tried a different ecu. Checked timing and it's good. I'm completely at a loss, my only thought I have left is if the crank position sensor in the dizzy went bad and the computer is extremely advancing or retarding timing to the point it ignites when the intake valve is partially open? I'm open to any suggestions at this point, thanks!

 

Wouldn't hurt to try another distributor if you've got, or can get, one.

 

Tried a known good distributor and no luck, any other ideas anyone? Thanks!

 

valves adjusted?

 

Update - Was a little busy this week but finally got around to doing a leak down test of each cylinder. All were given an input of 40 psi, here's how they checked out for leakdown:

cyl 1 - 37psi
cyl 2 - 39 psi
cyl 3 - 38 psi
cyl 4 - 39 psi

@TimiK I didn't spend the time to check the valve lash with a feeler gauge, but also don't think it would turn out alright on a leak down test if there was anything wrong with them, right?

I also can't imagine there is a mechanical problem with valve train timing or anything in the lower end, since the timing marks all line up at TDC and it passed both a compression and leakdown test.

I'm going to focus my attention on ignition timing as that's the only other way I can see it's capable of pushing air backwards out of the intake. Going to try a different wiring harness. I pulled a/c lines recently, perhaps I snagged a wire and partially unpinned it in the process. Any other thoughts are welcome!

 

Tried a different, known good, wiring harness and still the same problem. Backfired bad enough out the intake this time to burn some arm hair off. It sucked in air for a sec, and went right back to pushing air out instead. Spraying brake clean on the intake gasket area will kill the engine. Would an intake gasket leak cause this magnitude of an issue? I'm totally stumped. Help!!!