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.