Jump to content
Ecoboost Owner Forums

Idle manifold vacuum questions: 3.5L Taurus


gdavenport
 Share

Recommended Posts

All, I've been working through a bug that has my 2010 running rough. According to the codes, it had low starting fuel rail pressure (lift pump) and a cylinder misfire. I changed the plugs, and cleaned the injectors. The car is still running rough(rich?) and is showing 10"Hg (PID through the OBDII scan read). It smokes copiously, especially underload.

 

I pulled the upstream O2s to check function in Open Loop and the car runs better, but still smokes. In closed loop, the fuel trims quickly run to -30 (maximum allowed) on both banks.

 

What could be causing this?

 

The OBDII ports show full function (sensors vary based on conditions) for:

 

Throttle position(all sensors)

MAP - varies between boost and up to 28"Hg, settles at 10 at Idle

Fuel rail pressure (High side) varies from 65psi up to 1500 (maximum I can see at light/medium throttle)

IAT reads through the range

ECT reads through the range

 

 

Does this sound like a mechanical problem or a faulty sensor?

Link to comment
Share on other sites

What plugs are you running? Most of us have changed to the SP534 plugs gapped at .030. Don't know if that will help but it's something to consider because a fair amount of folks have discovered a big variation in plug gaps. As far as the others, don't have enough knowledge to give you any input.

Link to comment
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
 Share

×
×
  • Create New...