Burn

I will look at the ignition system next. I did.replace the spark plugs when I had the intake off for replacing injectors. Here is a video of the pathfinder when it is cold

Thanks for the reply. Yes I put a code reader on it but it didn't pull any codes. I cleaned the idle control valve, throttle body and egr when I had the intake off but i didn't test that it was working. I will double check the connections. I read that the o2 sensors are not in use until the engine warmed up? It looks like one o2 was replaced not long ago I pulled them to give a look. Distrubutor also looks pretty shiny so I think it was replaced. Was going to have a look and see if there is some carbon tracking or something messing with the spark.

Hi. I have a pathfinder I picked up cheap and I am trying to diagnose this problem. When it starts up cold it will start ok and idle fine but if you try to rev it up at all it just stumbles and losses rpm instead of gaining. So far I have cleaned the Maf, replaced the ECT sensor, threw in some other injectors and fuel pressure regulator and adjusted the TPS. It has around 43 psi fuel pressure hen idling and drops to 35 psi when shutoff. The fuel filter is new as well as the plugs. After it warms up it runs great. Trans shifts good and has decent power every now and then it will stumble at full throttle... but only sometimes usually it runs absolutely great after the initial cold stumble goes away. Seems like it is running rich from the look of the plugs I took out when I got it home. What else should I be looking at? I am at a bit of a loss as this only occurs when cold. No codes coming up