weird rpm surging problem
 

hey guys I have been noticing lately that when cruising about 30-35 at about 1000-1250 rpm the rpm gauge will surge from 1000-1250 and I can hear the engine surging as well not just the gauge. I was thinking plugs and cops. the truck is a 2004 f150 with 85k. didn't know if any of you guys have had this issue before. thanks guys

Anything else been done to it, or is it bone stock?

My 04 f150 does the same thing when I'm going between 10 and 20mph. It does it every once in a while. I'm not sure why though.

Mine will do it every now and again also.

only mods I have done is straight piped exhaust. drop in spectre filter. leveled with 33's nothing major. but this has been going on before I got the air filter

You might want to try pulling the throttle body and clean it, and clean the MAF too.

+1 on cleaning the maf.

No codes? I was thinking O2 sensor malfunctioning.

But either way I would start with the regular stuff like said above. Clean the MAF and throttle body, new fuel filter, see what happens.

Ok sounds good ill try that stuff today. I have no codes or lights and other than that small rom range it runs perfect and if I accelerate hard then I goes right by that skipping section and can't even tell

I also have an 04 SCREW with the same issues but it will also do it from a dead stop all the way up while accelerating and also at steady speeds. No mods except a K&N air filter and I cleaned the MAF and TB today, neither were all that dirty. Took it for a drive after and it's still doing it, any other suggestions?