Lean

[Contrldsub]

Like really lean. here is the sitEation. did a tune up in july. plugs, wires, coolant flush, oil, ran some fuel system cleaner and fuel filter, then ran Shell 89 for about 3 months. in Feb i put a cat back dynomax on it and a K&N intake and filter. the plugs that came out in july were fine no sign of an off running condition. i was checking all my cylinders with a scope and each plug was just about as white as ive seen. Power is horrible, gas mileage is about 16mpg's but i figure thats about what i get for having 31s on. Idle is kinda rough. burns an acceptable amount of oil for 171k, no coolant loss at all.

tests ive done:

Relative Compression
throttle possition sensor
Oscilloscope on each injector
Vaccum leak test
checked for unmetered air with propane

Im just about tapped out. i dont know what else to do or check. any ideas?

 

[James86]

Check your MAF sensor. the oils on K&M filters and other oiled element filters can muck them up - been there done that. Switched back to paper element and havent had problems since. Have you cleaned your filter sicne installation? Over oiling can worsen issues with your MAF as well seeing as the filament for the sensor is so small. My tires are around 31" as well and I get decent mileage for an auto with 4.10's (avg 18-19 mixed on gas, but prefer E85). Try cleaning your MAF and see if that helps any. Also, when did it start to run like hell? Pinpoint what changes you made and when, and that might help solve your problem.

 

[Contrldsub]

The filter is cleaned at each oil change. i have wracked my brain about what has changed and what i might have done to cause the problem. I looked at the MAF a few days ago but i didnt clean it, it did not look "charred" which is what i was told to look for. ill check it out again and just clean it for GP see what happens.

 

[James86]

You don't have to clean and oil the filter every oil change.

http://www.knfilters.com/cleaning.htm

You are definitely over oiling it then and it's possible you fouled your MAF. You're only supposed to clean it roughly every 50,000 miles, and thats straight from K & N. Think about it, if the MAF has oil build up, then the air moving across it doesnt cool the wire as effectively, so the engine sees diminished air flow, so if it doesn't think much air is coming in, it isnt likely to inject as much fuel, so if you apply gas, the MAF doesnt see as much of an increase in air volume, right?

 

[Contrldsub]

yeah i cleaned the MAF today.not the problem. blown head gasket. number 6 cylinder had 35psi of compression, all the others were at 145-155psi. Explains the poor power, and hopefully the lean problem. as for the too much oil, thats really only an issue IF you dont follow the procedure to cleaning and oiling. but i do see your point none the less. thanks for he imput. i know what im doing this saturday.