Hello,

I have a 2003 Ranger XLT that I bought in San Diego in 2005 with 4,000 miles on it. I've driven it ever since and have taken great care of it and it has taken great care of me. Starting around 60k miles or 15 years ago, I noticed that on level ground while driving at just above idle the truck would surge a bit, enough that you could feel a rocking motion, backward and forward.I put that in the back of my mind and let it go. Last year my air intake manifold plastic piece at the end next to cylinder 1 wore off and I had it replaced with a used unit.Ever since then I've had a rough idle (most of the time), sporadic power delivery and as of this week when I accelerate hard my AC shuts down. I think the AC honestly is a vacuum leak because it runs great all other times. I have sunk some money into it over the last year to get it back to running normal but my normal mechanic is hitting their limit on what could be the problem and I'm close to taking it to Ford for a diagnostic.

I myself did some basic items to try and fix it but I am no mechanic.
Spark plugs
Plug wires
Ignition coil
Air filter
Oil change
Fuel system cleaner (1 tank)
Cleaned the IAC with carb cleaner.

My local shop completed these
Smoke test
Compression test
Replaced the throttle position sensor. Did not improve, original put back.
Replaced the fuel filter
Induction service

I'm not really sure where to turn at this point short of giving it to Ford and seeing what they say. Any wisdom would be appreciated.

 

I had an issue with the CHT sensor that produced some wonky symptoms, you may want to check that..

CHT Cylinder Head Temp sensor

 

Thank you for your reply. I do have strange issues with my temp gauge too. It will got down to nearly full cold while driving. It never goes above the middle cold hot though. The more I drive it the more I think this is something that is building up when I don't drive it for a week. If I drive it daily it seems normal but if I leave it parked for a week it acts up for the day.