New member in dire need -Injector Harness

[JeepKKbythebay]

Here is the knowledge I have on my newly acquired 2011 Jeep Liberty 3.7L. I bought it knowing it had a bad passenger head. The previous owner stated she ran it until it overheated and caused head damage, parked it and I picked it up after it has been sitting outside for a year. Once I got it home, I took it all apart and replaced the damaged head with a new remanufactured head also installed a new timing set. Once I got everything together I noticed it was dead. Key on would turn all the accessories on but no crank. I replaced the TIPM fuse box and it now cranks. I have cylinder pressure and spark in all cylinder’s. What I am not getting is injector pulse. My fuel pump is priming and I have pressure at the rails but with a noid light hooked up I get no pulse when cranking from the injector harness. I first replaced the cam position sensor but they did not fix my issue. What are some ways to figure out why the injector harness is not getting signal? Also I would like to mention that I am showing no engine codes when scanned using OBD jscan and no weird dash light while cranking. Please be as detailed as you can as I am new to the jeep world!

 

[JeepKKbythebay]

Anybody?

 

[DadOSix]

Anybody?

Wow!

Sorry you've been without answer for so long:

These 3.7 are basically all the same from kj to kk except early kj 02-03 had different computers and tone rings.

Of course, a lot electrically going on here :

1- did the grounds to the back of each head get reinstalled? Clean and tight? These are the braided straps that run up to the firewall.

2 - did the connector that feeds wiring to the right side (passenger) of the engine get reconnected? It is located on the left rear of the engine- right above the intake manifold? It feeds EVERYTHING on the right side - cam - crank - injectors - plugs.

3- if these all check, you are going to need access to a real-time scanner that can check several pids at the same time. You'll be looking for crank signal, cam signal, crank voltage, cam voltage.

4- were any of the connectors for the ecm disconnected?

Remember that the ecm sends signals by GROUNDING the thing it wants to control. If the grounds are not good, you get failure.

Final thought for now - i didn't find a noid lite that was particularly bright on my 06. The kit i had didn't show a chrysler specific noid, but the injectors are bosch, so i picked that. I was expecting a bright flash, but instead got dim pulses. But pulses are good, as the signal is changing. Steady light indicated short somewhere between the ecu and your noid.