Looking at QX4 that surges

[vfrkent]

Hi guys new to forum, last night I was looking at a 2001QX4 that seems in very good condition with 105K miles on it, the one thing that stood out was it seemed to surge a bit under hard acceleration and not pull as hard as I would have expected, I read the post about the power valves screws and that has me concerned, also is there a way to rotate the valves with out disassembly to verify that they are not bound up from the screws coming out and a valve jamming the linkage?

Regards,
Kent

[Towncivilian]

I think you're overlooking the simpler things. It sounds more like a clogged or partially restricted fuel filter, as a filter in such a condition can interfere with achieving higher RPMs. It could also be a dirty MAF sensor, or simply spark plugs due for service (in fact, the replace interval is 105k). Of course it's a possibility that it is something to do with the power valve screws, but you wouldn't know until you remove the upper intake manifold collector to take a look.

[WPGQX4]

My 98 QX4 has 185,000km. I bought it with 167,000km. I thought it would have had the plugs changed in at sometime before I bought it. I changed them this week and found they had never been changed. My Q acted like yours before I changed them. Now it drives like a brand new vehicle.

[coledog188]

What plugs did you put in?

[WPGQX4]

NGK Irridium