missfire issues that is hard to trace. help please

[kysar]

I recently bought a 96 legacy sedan with a 2.2L auto. when I bought it, cylinder 4 was cracked. so I got a used short block and pieced a new motor together a few weeks ago. upon installation I replaced plugs, wires, fuel filter, p.c.v, timing belt etc. it ran great till last Friday. I went out to go to work and it wouldn't start. I pulled the hose off the fuel filter to make sure it was getting fuel, and nothing. so I put a new fuel pump in it, still nothing. after playing around under the dash trying to locate the fuel pump relay, it started. the old relay was so hot that it almost burned my hand. so I put a new relay in and it ran great again. today I pulled into the gas station for a second (didn't get fuel) came back out and wouldn't start. finally got it to fire and was running rough. so I hooked my computer to it and found cylinder 1 and 2 are misfiring. if I attempted to give it gas, it would only make it worse and then die again. now I cant even get it to start. any ideas? maybe something small that I am missing here but any help would be appreciated.

thanks Adam

[lmdew]

My bet would be on the fuel pump itself.  The high current draw was most likely making the relay hot.  A new relay with new contacts provided the needed voltage to the pump, so it ran well for a bit.

 

If you have an amp meter check the current draw for the pump.  I get used Subaru pumps out of the yard, over aftermarket junk.

[Prwa101]

Check and see if you getting spark at the correct timming.

Cheak and see if your timming marks are correct.

Cheak the power to the fuel pump relay wires(voltage meter), when you turn the key in the "on" posistion it should send power to the fuel pump(you'll hear it turn on). Should be the larger wire. Then it'll turn off because its primed.

 

Could be the Ecu or coil pack

If it has a new fuel pump in it I would lean away from that.

[MilesFox]

I second the timing alignment. The arrows are not used, common mistake if inexperienced with subarus. Not implying, but worth a mention. good luck

[Fairtax4me]

Camshaft Timing would not cause an intermittent no start issue. Either it's right or it isn't. It runs flawless or it runs like spoob, no back and forth.

 

If the fuel pump relay was hot there is a high current draw in that circuit or a poor connection to the relay.

Did you check the connector to the relay for any signs of corrosion or burning?

[ivans imports]

did you change pump ? sound like the comutator bars are to worn and pump is shorting

[mikaleda]

Was the fuel pump new or a new to you used pump?