1999 Ford Expedition missing on no 6 at low idle

Hi there,

Check the compression on that cylinder check for a vacuum leak around that cyl and check injector is ok, do this next.

Mark (mhpautos)

I did replace the injector but not thr compresson

Check the compression and check for vacuum leaks next,

Mark (mhpautos)

The compression is ok, vaccum line ok, what else could it be? When you come to a stop and it idles it kicks back a little not all the time. We also put a MAF sensor.

Hi there,

you will need to get a read out of the actual Kva ignition readings when it misfires, this will prove the ignition system one way or the other, but if it is only 1 cyl, you may have to re check the ignition system for No 6 not just visually but with testing equipment this may now be a job for your mechanic, let me know if you need technical information, I will post what I can.

Mark (mhpautos)

I have took it to A Ford Dealer they can not find anything. So ford dealer mechanic is no good. I took it to them 5 times.

Hi there,

this may be a fault with in the ECU, I would talk to an independent work shop about trying a test unit( This is an ECU that has been confirmed that it has no defects) this will prove the ECU to be good or day, I would go here next.

Mark (mhpautos)

What is a ECU?

Hi there, this is the main computer that controls all engine management parameters.

Mark.