I have had this as a flashing MIL and just the other day i came as a solid light. I am about to pull my hair out over this. I have changed all the injectors and plugs wires. no need to change cooil packs because I have swaped holes on them and the misfire still remains with cylinder 4. I have also checked the compression and all cylinders are within 2-5 lbs of each other. This is a 98 T100 with 182000 on the clock. The only thing I think it could be is the new injector that was put on #4 was also bad but what are the chances of that happening? also could be a valve clearance out of spec but I am at a loss. anybody got any ideas?

 

5vz? did you swap the plugs? What did the plugs look like? so you already tried moving the coil pack to another cylinder? What are the compression readings? have you checked valve clearances? did you swap clean known good injectors? or used ones?

 

Yes it's a 5vz. Yes I swapped plugs, I actually put new ones in. Yes I've already swapped coil packs with another cylinder. compression reading on 1-5 were 200. compression on 6 was 185. No I have not checked valve clearances. I put new injectors in it.

 

Is it running rough at all? Do you have freeze frame data from checking the code?

 

Did you perform any maintenance prior to this condition? Maybe you bumped/damaged the injector harness?

What did the #4 spark plug look like after the condition appeared? Was the end wet with fuel?

What did you do to test to see if the injector was gitting the proper signal/voltage?

Also...as a quick check...you do know that the #4 cylinder is on the left side of the engine aka the driver's side.

What brand of wires do you have on there? What is the current resistance measurement of the #4 wire? It's possible that the wire may have failed even though it is new. Did you confirm that the plug is firing?

What brand/model of spark plugs do you have in there?