Jbrew

This is confusing, first of all , nobody has 7 coilpacks. Theres only 2 coil packs and they are on the 4.6L's 97-00 model years.

The 5.4L motors have COP systems. You never said what motor you have , so that makes it hard to help ..

If you have the 5.4L and your still getting the 303 code , the COP is bad - it doesn't matter if it's new - it's bad..If you aren't using motocraft plugs in the 99 , then that's a major problem as well..

whitecrystal1

I agree with Jbrew and think you still have a problem with either the coil or plug with #3 cylinder. Is the coil seated on the plug all the way? How many miles are on your truck? Is it only running rough at Ideal or is it also rough while driving it?

You said you can here the injector clicking but the only way to really know is to test it. You can get a Noid to test it with pretty cheap at your parts store. You should go ahead and test the 02 sensor as well as doing a compression test just to confirm and rule things out. If all this test good then it may be the cpu that's causing this problem. I hope if that's it it's not too expensive. Also about the catalytic converters, Like it says in the obdII.com page, If it's smelling like rotten eggs then a converter is probably bad. If it smells rich then it's not burning all the fuel (#3?). I'm still leaning towards the problem being between the coil and the plug though. Sorry I can't help more, I just don't know what else to tell you other than that. please post what you end up finding...Good luck with it.

ccculbreath

Ok to make it easy on you, it is a 5.4L with the COP system.(you should have picked that up if you have read all the replies). And I really do not see how a new coil pack could be doing the exact same thing as the old one. I'm using Autolite plugs which is the same thing as a motorcraft. By the way Jbrew since you came up with all this info I missed giving you. Can you give me some credentials before I go pulling "coil packs" out and telling the people at the parts house thier parts are bad... Now I'm glad that you've replied any help is good

ccculbreath

whitcrystal1, thanks for the help. The o2's were replaced back in the summer.(that's not to say they aren't bad). I'm thinking some electrical problem with the wiring harness and the CPU. I'm going to get the noid light,and some other test ignition test equipment to see if everything is cool. It's so dang cold that I'm not really wanting to jump in there. If I'm not wrong isn't there two set of o2's total of 4? Thanks so much and I'll let you know.

whitecrystal1

Btw, Have you thought about switching the coil and plug from #3 cylinder with any other cylinder then clearing the code to see if it comes back and changes the code to that cylinder? That is an easy way to tell where the problem is if changes it.

Jbrew

Your an idiot - you don't evem know what your working on COP's Coil Over Plug

Coil Pacs - have wires and run 4 plugs jerk!! i WAS ASKED TO HELP , i DIDN'T VOLUNTEER

ccculbreath

whitecrystal1, I just thought of that taken what Jbrew said about it might be bad (the coil pack) Jbrew I do not like being called an idiot or a jerk. You was asked to volunteer but know one said you had too!!! I didn't know it was a play on words that you got so uptight about. You go to the parts house and ask for a coil pack for a '99 and they give you A COIL PACK that goes over the plug...Oh and you might want to proof read more often evem is not a word. And when your trying to come off being smarter than the person your writing to,it makes you look like the idiot.

LovetheTide

Is it me or are there a couple of peps on fire.

Jbrew

LOL , spelling is one thing - at least I know what I'm talking about.... I accused you of ignorance because you doubted what I was telling you (what would you call it?)If you go to the parts store they look up your motor and then a part number..Instead of listening to you and giving you the wrong part - If they gave you a coil pack , you would be completely lost - more than you are now - You have a "coil " over each plug , not a coil pack, that's all there is to it. Why should I have to guess at what motor you have ? there three for your year.. Your the one that needs the help, don't you think you should post you motor ? u no - the one your having probs with, it would be easier to help..

COP systems as they age break down - the thermal layer gets weak and they lose there punch. The absolute best possible tune up that you can give the 99 motor is to change the COPs at the same time and for the love of God, get them Autolites out of there, they will screw up everything within time..Bad COPs will pass Primary and Secondary testing all day long .. However , this is not where they fail the majority of the time. The most common failing point during a drive cycle is the shift from Drive to Overdrive , approximately 45MPH right after the shift you'll get a misfire..You can not test this without a history reader - Mode 6 measures history per each cylinder and this can be done only at the dealership by certain qualified tech's. Global Automotive out of Florida sells F150 kits 8 COPs and 8 new Motorcraft plugs for $130 . That's a resource you won't beat - do yourself the favor....

Autolite does manufacturer Motorcraft plugs - true that, they even look identical - guess what ? the 97 -99's won't run right with the autolites because the ceramics/porcelain are of an different heat range - it varies enough to eventually cause multiple and random misfires .. I have a set of double plantinums that I can't use in my truck or any others here of that year because of the heat variance.

The 5.4L is a high tech design and is picky about the plugs you throw at it . You have the PI head design in the 99. To get full performance out of the 99 you need to run OEM Motorcrafts, NGK'S or Iradiums. If you want it fixed you need to listen up !!

What else you should look for is your heater core feed and return lines leaking over #4 , It's hard to tell sometimes because heat and air tend to dry it up fast. With age those hoses deteriorate from the inside out around the fitting and leak under pressure...

Another BIG problem is the wire harness being to close to the accumulator.. This will make the motor run very poor. I have (while the trucks running ) pulled the harness away from the accumulator and noticed a change in idle.. Your ignition system gets buggy if it's to close , trust me, I know .. Just keep it away ..

I have seen many TSB's about these problems and worked the field for many years. Credentials ? LOL , yeah , I have them , I'll tell you what - you just use your own due diligence when it comes down to your motor. I will say that I'm an engineer and a part of team that was assigned to build Fords Parabolic track in Dearborn 2004 - 2006. I just can't spell worth a sh^t..

denvertruck

JBrew, I have a question for you and I will not ask for your resume, LOL. I have a 2004 F150 5.4 (new style not heritage) with 60,000 miles. I am getting a very short engine cutout while I am driving and then is runs normal. I have not noticed a certain speed that it happens but it does not seem to have when I am accelerating. I had an explorer that did the same thing and I had to change the fuel pump. Does this seem like the right solution?

Thanks for you help