LM7 in a Jeep runs rich
#1
LM7 in a Jeep runs rich
I have a ’97 Jeep TJ with a 2003 5.3L LM7 out of a 1500 truck. The harness and computer tune came from Wait4Me Performance. It is supposable a 375 hp tune. It runs good but it is very rich. I have run the codes on it and I get a P0135 and a P0171. From what I have read the 171 code was most likely a dirty MAF sensor. I cleaned the MAF and the code has not shown back up. I am only running the 2 upper O2 sensors. The rear 2 have been deleted in the computer. I have swapped the O2 sensors and traced the wires as far back as I could looking for heat marks, frays, etc. The wires look good. I even replaced the O2 sensors but still can not clear the 135 code.
My concern is the running rich part. I’ve got about 49 PSI at the fuel rail with a P5000 pump. The intake and exhaust are pretty much wide open with just a filter on the intake tube and a Magnaflow muffler with no cat. I’ve checked the fuel filter and plug wires.
I’m new to the trouble shooting world of the LS style motors. I can fix it if I can get some direction. Any help would be greatly appreciated.
My concern is the running rich part. I’ve got about 49 PSI at the fuel rail with a P5000 pump. The intake and exhaust are pretty much wide open with just a filter on the intake tube and a Magnaflow muffler with no cat. I’ve checked the fuel filter and plug wires.
I’m new to the trouble shooting world of the LS style motors. I can fix it if I can get some direction. Any help would be greatly appreciated.
Last edited by 5.3JeepTJ; 05-19-2009 at 09:56 AM.
#2
TECH Apprentice
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I think Jesse just tunes air/fuel on the rich side. I had the same issues with a tune from him before. Contact him, he is pretty good about corrections. Or have a dyno tune done to get it right on.
#3
TECH Resident
You need to fix that bank 1 O2 sensor issue first. Have you verified heater voltage and ground continuity down to that sensor connector? Checked O2 fuses, etc? If the heater wiring is ok, verify signal wiring continuity from the O2 sensor connector pins back to the PCM connector.
Once all that is fixed, you should really be seeing 58psi at the rail..
Once all that is fixed, you should really be seeing 58psi at the rail..