3.0 troubles - missing/running lean

[Bray D]

96 ranger, 3.0L, m5od, etc. 153k miles

Here's the story:

Its been running fine up till lately. I started up my truck one morning, and it was missing (sounded like running on 5 cylinders). Drove it to school and back (~60 miles round trip) and started trouble shooting.

Pulled the wires and checked the resistance in the coil pack, seemed like coil is still good (per Haynes manual). Went ahead and bought new plugs and wires, thinking that'd do the trick. Swapped em out, started it up, ran fine. Problem solved. Shut it off, clean up shop, start it to back it out and its missing again. Take it for a spin to see if I notice anything else.

Back to trouble shooting. New symptoms (maybe I didn't notice before): exhaust smells funny. The missing gets worse with throttle position. I could run 55 in fourth gear at a higher RPM, but had a hard time holding 55 in 5th cause I'd have to give it more gas to make it up hills and such. Old plugs were white (running lean). I had a new EGR valve layin around so I threw that on there for kicks, no change in symptoms.

Idle is at normal RPM and the missing occurs throughout the RPM range. My next step is to check the resistance in the fuel injectors, then a compression check.

Any ideas

 

[Ranger44]

Running lean can be caused by more than just ignition and fuel. Mostly caused by unmetered air getting into the engine. It can make it run rough.

Have you looked for any loose vacuum lines?

Were the spark plugs a white or fuzzy white?

Hmmmm. Have you cleaned the MAF?

Any cracks/tears or leaks in the intake tube?

Good luck Bray.

 

[Bray D]

I had a suspiscion that my check engine light was burnt out so I took it to Autozone to have them check it out. I was right, pulled 4 codes! 3 of them were random crap that didn't matter, but one was for my cam position sensor. went home, took the sensor off, and sure enough that was it. The magnet had come out of the sensor and beat the piss out of the cam syncronizer. Called Napa, new syncro with sensor was like $105 (with core). Came in today, replaced it, and all is well.