My 98 Montero Sport has been giving me grief lately. I installed new timing belt, water pump, crank sensor and spark plugs. When starting cold it runs well. After it warms up it wants to stumble and cut out. If you manage to drive it around for a few minutes it will start to run a little better. The check engine light came on and my scanner indicates P0174. Checked several things listed on my scanner. When I checked the O2 sensor connectors, I have 12 volts for the heater, good ground, but no 5 volt refence from the computer. Am I supposed too? All wiring from both O2 sensors to the computer are good as the ohm out. Could that part of the ECM have gone bad? And would this cause it to act like it is running out of fuel for a bit? Ohhh, I also installed a new fuel pump because the old one died along with a new filter.

Pulling my hair out here. Thanks for any input.

 

Check for vacuum leaks, p0174 is bank 2 lean code. How does the truck run @ idle?

 

Runs perfect at idle for the first 7-10 minutes. Then as the truck warms up to operating temp it starts to cut out at idle, then will go back to idling fine. If you can get through the cutting out after it starts acting up, then it will start running better. After about 10 miles or so, you can drive pretty well any way you want to. I have searched for a vacuum leak, but not found one, though I have not disconnected thebrake booster yet. I may have a look at that, though the brakes seem to be working fine.

This truck had lots of troubles when I got it. Would not start at all. The main fuse (100) amp was blown beside the fuse box under the hood, and someone had startedtaking out the alarm system because they couldn't get it to run. If I can get this glitch worked out, it should be a sweet ride.