My '02 F150 has 112k on it and I've been experiencing the mis or stumble under load since I bought the truck in 2004. It's always been very minor but noticeable none the less. The problem is exactly as described... Begin going up a hill, touch the accelerator, misfire / stumble happens... Sometimes minor, sometimes horrible. For years I thought it was transmission related and I would just have to wait for it to go out. Then I thought why not try google... After trying many different wording combo's I finally stumbled onto this site and the many threads discussing the issue. My question is this...

How do I make sure this is what my problem is and how can figure out which COP is too blame? I'd like to stick with motorcraft COPS and get the more reliable model now (DG508) but the cheapest I can find an entire set is about $335. The stealership here wants $100 for a diag test which seems a bit high too tell me what I already suspect. Is there a way I can test each or visually inspect? Should I just bite the bullet and replace all? I don't do a lot of driving each year and would like to keep this truck for a long time as I've taken very good care of it this long. I handle all my own oil changes, routinely clean the MAF, IAC, and throttle body. I prefer doing the maintenance and repairs myself if possible so I can guarantee quality.

Open to any and all suggestions...


Thanks,
Chris

 

Have the plugs and fuel filter been changed?

 

The first thing you should do is replace the spark plugs. With 112k they are overdue. Don't worry about cops till you do that.

Motorcraft plugs, no antiseize, 28 ft/lb torque, dielectric grease in the boots.

 

I meant to include this earlier... the plugs were changed about 20k miles ago and the fuel filter probably 30k miles ago. The misfire / stumble problem has always been there, even when I first got the truck with 20k miles on it. I thought the COPS were sure to blame based on the symptoms and was going to look at replacing COPS and plugs at the same time. Then I saw how much 8 motorcraft COPS were and thought I better slow down and try to diagnose first. I would be fine with replacing the fuel filter and plugs again but would like to avoid replacing COPS that aren't currently bad.

 

It's hard to identify which COPs are misfiring unless you get codes on particular cylinders and can swap COPs around to isolate a bad one. I would look at change them all if it were me, but I would probably buy the cheap ones off ebay. You may have some boots that are cracked and leaking fire. Also, 30,000 is about max on the fuel filter, though that does not sound like your problem.

 

Are there cheap COPS that are more reputable than others on eBay? I assume the only difference between the cheap eBay COPS and motorcraft is how long they last?

I guess I could look at doing all plugs, COPS, and fuel filter... Has anyone on here had a bad experience with the cheap COPS?

 

The best compromise on cost vs. quality on cops are Visteon 60-1000. They are essentially OEM, Visteon was a Ford subsidiary. The cheap cops seem to be a crapshoot these days, they are poor Chinese quality.

http://www.ebay.com/itm/VISTEON-60-1000-Ignition-Coil-Ignition-Coils-/330836213376?pt=Motors_Car_Truck_Parts_Accessories&hash=item4d075ffe80&vxp=mtr

 

I'm really wrestling with this but I'm leaning toward replacing all plugs / COPS and using motorcraft. Don't really want to put in all this labor myself and end of with poor quality COPS that have to be changed soon. What is the recommened interval for changing fuel filter? 50k?

One other question... Was this a design flaw on the original COPS? Seems like I read somewhere that the DG508's were a different model than the ones originally used because a problem was found with them. I only ask because I do recall noticing a slight hesitation the first time I drove the truck. It has happened sporadically over the years since then and only a few times was it really bad.

Thanks for the input so far...

Chris

 

Also, I wouldn't be opposed to the Visteon COPS if they are as good as Motorcraft, I just can't seem to find them anywhere. Google doesn't turn up much and eBay is littered with some many knock offs. Rockauto doesn't list Visteon as a manufacturer.

 

One more thing... I used ford's website to get my motorcraft part numbers and found that the COPS are listed as DG491 instead of DG508... what gives? I thought DG508 was the recommended replacements?

 

The link to Visteon cops on Ebay is in my post. They are the SAME THING as Motorcraft, Visteon made the cops for Motorcraft. 60-1000 is the Visteon part number.

DG508 is the standard Triton V-8 cop for all 2 valve engines.

It's very possible the cops got wet before you bought the truck. This can kill them.

 

You need some diagnostics. If a cylinder or cylinders are missing, a code reader should be able to tell which ones are at fault. Just replacing all of the coils may not be the right way to go. It is possible the problem is something else. If you have been having the problem since 2004 (10 years!) and it has stayed the same, I would definitely want to do some good troubleshooting first.

 

Almost sounds like a loose fuel injector plug, but you have to start somewhere.

First before you go and spend all your hard earned cash on stuff you may not need, it pays to take about 30 minutes to nail down the problem.

I would start by checking all the plugs to the cops and injectors making sure they are securely on. (I've knocked an injector plug loose while doing something else, it happens) After you know that is not the problem, grab a vacuum gauge. IF you do not have one, they are cheap and handy to have.

So if it is not a loose plug, on to checking the cops for the culprit. Look at your fuel rail on the driver side. You will see a (red) vacuum line running over to it as part of the return. unplug it and plug the gauge you have into it that lone, not the rail.

Now all those plugs you made sure are connected, go ahead and pull them one at a time while looking at the vacuum gauge. One or more of them should not make the gauge drop. So which ever ones those happen to be, those are your bad cops that need to be replaced. If you do not see any vacuum drop after checking each cylinder one at a time. Well it's not the cops.

I would also check the plug before buying a new cop too. You can get a cheap spark tester for less then 5 bucks at most part stores to verify if the cop is dead. I had one plug arcing up the porcelain without a carbon track to help it along. I'm still not sure why it did that but a new plug fixed the problem.

As to the cheap cops you can get on ebay or amazon... I freely admit my cheapness. I bought the set form amazon of 8 cops for $57.67. One went bad in the first week after install. I emailed them and had a new one in a day no charge and hassle free, that was 10 months ago and I have not had a problem since.

I would advocate spending a bit more for nicer ones, but I was in a bind and couldn't see spending around 100 each from the dealer at the time.

Hope all this rambling helps.

 

Oh as to the labor of doing it yourself, yeah it's going to take a few hours your first time most likely. But once you figure it out, it should go quick. First time I think it took me about 4-5 hours, now to replace all the cops and plugs is closer too 30 minutes to an hour.

I would bet there is a nice step by step on these boards, but if not shoot me a PM if you go to tackle it and I'll see if I can get one up for a reference this weekend.

 

i would like to stick to motorcraft cops as well, but they are not cheap. i havent had any experience with them, some people say they suck some dont but thought id throw this heads up but accel has a set of 8 for 183$ on amazon. i was goin to do plugs and these at the same time soon because my truck has a few different brands in there right now. just my 2 cents