Fuel Injector wiring problem

[acw592]

I have a 97 TJ with the 4.0 thats had a missfire on cylinder 1 since I bought it a month ago. The PO changed cap, rotor, plugs, wires and the #1 injector. I checked the injector he put in and it was the wrong injector so I replaced it with a new, correct injector. The problem I'm having is when you pull the wire off of #1 and even #2 the engine doesnt stumble like it does when you pull the connector on one of the other injectors. Using a long screwdriver for a stethascope, you can hear the other 4 injectors firing but #1 and 2 sound very weak. I'm not sure how to check voltage at the wiring. My next step is to take the harness and unwrap all the wires and start checking them for damage. Any other suggestions? Thanks

 

[JPNinPA]

You are on the correct track. By pulling the wire off and the idle not changing usually notes it is not firing. The only other way to have an issue is the injector being on constantly.


JPNinPA
Using Jeepz.com app

 

[superj]

buy one of those noid lights. its from your local autoparts store. it goes between the injector and the harness to see if the injector is working

 

[k-2]

buy one of those noid lights. its from your local autoparts store. it goes between the injector and the harness to see if the injector is working

noid lights are must have tools - easy fast work of inj wiring. BUT I suspect there are codes - you removed 1&2 inj connectors no change - scan for codes even if CEL is off.