Cylinder 4 not firing

[streetspirit7]

Ok, for some reason my cylinder 4 is not firing. When I pull the plug wire or injector harness there is no change in my rough idle, so I should be a problem there. I'm still getting spark to that cylinder, so it must be fuel right? I've done the tests in the FSM, the injector harness has power and there is continuity between the harness and the ecu plug. The injector continuity has within spec, and I've tried replacing the injector. Could my problem be the ecu, or somwhere else. If it is the ECU, is there a way to check that without replacing it?

[CTS13]

Check simple things first. make sure the harness is not damaged or melted, check the plug for any hints, make sure your not losing compression in that cylinder, check the fuel rail and make sure theres nothing stopping the fuel from gettin into the injector. What engine are you talkin about anyways.

[Klits562]

i'd definately say a compression test is in order

[liquid_cool]

its not uncommon for the ecu to have a bad injector block..as a matter of fact..ive had 3 ecu's all with a #4 injector issue...try to barrow a buddys ecu and swapp em out to see if it fires..if not..for the time being...you can splice in a temp set of wires to preload your manifold with fuel so its at least driveable till you can get another ecu..works fine..i did it for a while myself...hope this helps.