Well,my surge at idle is back.No CEL.New Motorcraft wires and plugs a few weeks ago.My gas mileage is going south very quickly.I'm thinking its my coil.Any opinions?

 

Surge, TPS? Gas mileage, O2's?

 

I'm sorry.....let me explain a little bit better; the surge is only at idle.It kind of skips a beat.You can feel it in the seat of your pants.IAC is good.PCV is good.No vacuum leaks.I'm thinking coil because 2 wires were burnt at the coil when I replaced them.Any other ideas?

 

BTW,the O2s are less then a year old.

 

If I had to guess I'd say your TPS is shot, or you have a bad coil.

 

Well, I would think that A bad coil wil miss all the time, at speed anyway, not just at idle. Also would A bad TPS mess with MPG's?

 

I think it could be the coil; if it's not firing to its capability,excess fuel will be wasted,thus my bad gas mileage. If it were the TPS it would throw a CEL,rite?

 

I'm going to say you burnt your coil when you had those fouled plugs. Even if you put new wires and plugs on it, the coil might not be providing enough, or any voltage for that matter to those plugs. Your trucks ECU might still read that the voltage is in spec, thus not throwing a CEL.

But what could be happening is, the conductive path the voltage takes might be burnt, and is not conducting the voltage all the way to the intended output...the spark plug. Instead, it's letting the voltage out somewhere before the plug.

I'm just guessing, but that's my theory. I say it's a bad coil.

 

Well Mr. Fitter, have you changed anything yet? I ask couz my truck has a small mis and I've changed about everything but the coil(OE) and the wires(2.5 years ago with rebuild) that I can think of in the last six months. Let me know. Thanks.

 

Yep,replaced the coil this past weekend.No more miss,idles like a kitty kat.I went with a Borg-Warner coil from Pep Boys.It has brass inserts.After the 5% discount and tax it was $87.00 and some change.

 

Good to hear BOF.

 

Thank you, thinking I got to try coil and wires soon.