Hey all. I've been trying to track down a misfire in the beast to no avail. I've had the Ex since last Sept. and it's done it ever since I got it, but has gotten worse. It feels like a simple misfire. You can feel it at idle and it's even caused it to stall once or twice.

I did boots and plugs a while back, but no change. I also did fuel and air filters.

No CEL so no codes to share. I thought probably a bad coilpack, but without a CEL, how do you know? I took it to a buddy's shop. He SAID he put an oscilloscope on it and while all of the firing seemed ok, he said cylinders 4&7 were the weakest. I replaced those two coils but the problem persists.

What would you recommend? Do I take it to the dealership (gulp) and let them hook it up and scan it (most places say that no CEL means nothing to scan for on this motor). I don't really want to plunk down $600 on an entire set of coils if I don't have to to track down one bad one. I also heard rumors of vacuum leak issues on these.

Thanks all!

 

Is it just doing this at idle? Try cleaning the IAC (idle air control) valve/sensor to see if it helps to run smoother.

 

Did you try unpluging the Coil (COP) -one at a time- and listen for a change at idle? Maybe borrow a code reader or see if the local auto shop will read them for you?

 

the problem with unplugging a coil is that with an intermittent miss, that won't help. The truck will run so poorly, you wont feel a slight miss. It'll be missing all the time.

Like I said, there are NO codes because no CEL. I've had it scanned in the past, but I'm told without a CEL, it won't read anything.

thanks for the reply

 

I would say get yourself a single new coil and replace it one by one to see if it improves. For example, replace #1 coil with the new one. If no change, then put the old coil back on #1 and take the new coil to #2 and so on until it improves.

Check the wiring harness to make sure you have a good connection also.

 

Thanks, but what if two are bad (or partially failing)?

Could this be an injector issue?

 

I had the exact same problem. I used a Auto Enginuity to watch misfires by cylinder. Mine had problems with cylinder #6. I replaced the coil pack with an Accel one (it was cheaper than the motorcraft) I think it was $42.

Solved my problem.

FWIW, I replaced the boots first, thinking it would fix it. It didnt.

Mine didn't show any codes either. I had the same stalling issue. Stalled either at idle at a light or upon acceleration from a standstill.

 

so is their product capable of monitoring cylinder misfires but other ODBII scanners aren't? Say if were to take it to the local parts store that scans for free, will their scanner NOT be able to see the same thing?

I guess even if I have to shell $250 for the PC pased one, at least I'll have it to do more with:

ScanTool PC-based

i also see them on eBay for ~$120 inc shipping

 

Yes AE is. I would think other "better" can see misfires. The one at my autozone only can read codes.

I would ask if anyone in your area has a code scanner that can help you. I'm in Philly area, if you are close by, let me know and I'll use my AE for you.

 

Thanks again. I USED to be in the Philly area, but a road trip to South Florida is probably out of the question, eth? lol

I asked AE if I needed the "complete ford package @ $400" to read misfires or will the basic $250 setup work. He said "you'll want" the $400 pack. Do you know if i NEED it?

 

Yes some scanners can read misfires. But the cheapy ones wont. Im used to the tech2 as im a gm tech. If ur able to see that data ud know. What cylinder (s) is causing ur issue. It sounds like it def enough for u to feel but not bad enough to set a hard code. With a good scanner u can view the data and possible see the soft code, the data that will eventually set a hard code that the cheaper scanners can see.

Without that id say payin for diag (most shops is 1 hour) is a good deal. They would give u the data u need to go home and swap out the bad parts. Well worth $100 bucks if u dont have the right tools

 

I think you'll need the "Ford Enhancement".

FWIW, this AE software is pretty awesome. I figured it this way. One coil pack cost me $42, all 10 would be $420, so the AE was free to me.

You'll like AE, I'm an old school mechanic (if it has fuel and spark, it'll run), these "new" vehicles has 1,000s of sensors.

It'll pay for itself over and over. Good luck. If you need anything, pm me, I have an '02 V10 since new, I know that model pretty good.

 

I had a miss in my pickup and had it scanned twice etc, no codes. Finally bit the bullet and bought a couple of Accel COP's from Jegs, they were on sale for 30 each about a month or so ago. I bought 2 because I didn't want to do it 1 by 1. I figured my time was worth another $30 bucks. Anyways, I fixed it on the first try. Also I think an 8 back of Accel COP's on Jegs is decently priced.

 

Mine is doing this but i replaced all 10 plugs and COPs and the problem persists....

 

This is an unlikely situation, but I have heard of it happen. The wire harness that plug into the COP can arc to ground. Try taking the hood light bulb out when its dark and see if you see an arc at idel. Kinda jiggle the COP wires a little and look closely for an arc. The only reason I mention this is because sounds as though you have tried about everything else. It won't take long and it is fairly easy to do.