Hi all. I am having a hard time figuring out what is wrong. I have a hard time starting car, sometimes. 3 to 5 cranks....engine light on...when i accelerate hard the car sputters and jerks. Throwing code too lean. Smoked vac. system all good. New fuel filter, added injector cleaner and did MAF cleaning. Any thoughts? Car is 2004 XJ8 . The codes its is throwing are P0171 & P017.

Thanks,

Tom

 

I had similar experience, only add huge volume of white smoke, traced it to I left oil filler cap off, when removing plastic engine cover.

 

Hi talashek,

There are multiple possibilities, so can you please tell us all the exact codes that were stored? Also, please tell us the year, model and engine of your car so we can give you relevant suggestions. It helps to add this info to your signature line using your User Control Panel so others don't have to ask.

Cheers,

Don

 

Sorry Don...I could not figure out how to include car profile in signature but I did edit post.

Tom

 

Should the 2nd code (P017) be P0174? If not, what?

If it may be an air leak, watch fuel trims at idle and again at 2500rpm. What happens to LTFTs?

 

Yes Sir 1704.
I don't think leak. I smoked it and could not find a leak. Forgive my ignorance but what is "LTFTS"?

 

See my sig...

It may even be misfires but I'd expect P030x codes.

 

Same thing happened on my 2004 X350. I found on acceleration, engine torque would pull the air inlet snorkel off the throttle body, but while driving would reseal itself. the tube was rather hard with very little flexibility. I had no codes.

 

Could be a bad crank sensor??

 

Check your PCV valve. My 06SV8 threw those two codes (P0171 & P0174) when the PCV valve was disconnected from the nipple on the back side of the plastic intake tract. The codes are lean condition in bank 1 and 2 and indicate an intake leak somewhere.