Hey all,
I’m trying to track down a rich-running issue on my 1995 Land Cruiser with the 1FZ-FE, around 248k miles.
The original code I had was P0170. I replaced the upstream O2 sensor with a Bosch sensor, but after swapping the connector I ended up with a P0135 heater circuit code. I’ve got a Denso sensor on the way and plan to put that in next. I did try to coordinate the wiring on the Bosch with the factory harness but no luck.
The oil has had a pretty strong gas smell to it. It definitely smells fuel-contaminated and it's thin. No knocking, no low oil pressure, no obvious blow-by, no rough idle.
I pulled all six plugs and they all look pretty much the same. The current plugs only have about 500 miles on them. None of them looked wet, and there wasn’t one cylinder that stood out from the others. The old plugs were also pretty uniform.
I also ran a borescope into the cylinders and didn’t see any obvious wetness or signs that one cylinder was getting dumped with fuel. I checked the vacuum line on the fuel pressure regulator and it was dry. I’ve also recently done the FPR vacuum hoses, vapor canister/hoses, WIX air filter, Denso plugs, and an oil change with Valvoline 10W-40.
At this point I’m wondering if this is more of a whole-engine rich condition, instead of one bad/leaking injector, since all the plugs look evenly sooty.
For those of you familiar with the 1FZ, could a bad upstream O2 sensor cause it to run rich enough to soot all six plugs or do these plugs look normal after 500 miles? The oil was also changed 500 miles ago and once again has a strong gas smell. Should I still be looking at injectors/fuel pressure?
Any advice is appreciated.
I’m trying to track down a rich-running issue on my 1995 Land Cruiser with the 1FZ-FE, around 248k miles.
The original code I had was P0170. I replaced the upstream O2 sensor with a Bosch sensor, but after swapping the connector I ended up with a P0135 heater circuit code. I’ve got a Denso sensor on the way and plan to put that in next. I did try to coordinate the wiring on the Bosch with the factory harness but no luck.
The oil has had a pretty strong gas smell to it. It definitely smells fuel-contaminated and it's thin. No knocking, no low oil pressure, no obvious blow-by, no rough idle.
I pulled all six plugs and they all look pretty much the same. The current plugs only have about 500 miles on them. None of them looked wet, and there wasn’t one cylinder that stood out from the others. The old plugs were also pretty uniform.
I also ran a borescope into the cylinders and didn’t see any obvious wetness or signs that one cylinder was getting dumped with fuel. I checked the vacuum line on the fuel pressure regulator and it was dry. I’ve also recently done the FPR vacuum hoses, vapor canister/hoses, WIX air filter, Denso plugs, and an oil change with Valvoline 10W-40.
At this point I’m wondering if this is more of a whole-engine rich condition, instead of one bad/leaking injector, since all the plugs look evenly sooty.
For those of you familiar with the 1FZ, could a bad upstream O2 sensor cause it to run rich enough to soot all six plugs or do these plugs look normal after 500 miles? The oil was also changed 500 miles ago and once again has a strong gas smell. Should I still be looking at injectors/fuel pressure?
Any advice is appreciated.
