Hey there fellow x owners ! I am a proud new owner of a 2000 X 6.8l 2wd with the 4.3 rear end .

I have had the truck for 2 weeks now . When I bought her , she ran a little rough but I expected as much after sitting for 6 months ... After driving her home I began to start a massive tune up , because she was acting like there was a miss ... The miss only started after she was at normal operating temp and at first only when at cruising speeds in overdrive on the freeway , it progressively got worse ... The miss became all the time once up to normal operating temp but will do it wether she is in any gear or even park .... Oh and the miss is NEVER at the same time it is always completely random ...

I have changed all 10 coils , all 10 plugs , the PVC valve , and I am changing the fuel filter this afternoon ... Other then that I think I can hear a vacuum leak , but I have tried spraying carburetor cleaner around the engine bay as instructed by a " ford expert " at the local auto parts store and I did not notice any change ... After I install the new fuel filter I am going to fill her full of 93 octane and add a bottle or 2 for Lucas octane boost as well as the Lucas injector cleaner ...

Other then these things I am at a complete loss ! This is my first v10 ford so I am a little at a loss ... Now if this was my wife's BMW 760 or my Lexus IS 300 I would not be having this problem lol

So any input would be fantastic !!! Thanks guys & gals

 

The higher octane wont change anything - but a bottle of Techron fuel injection cleaner may help some. I get a slight miss in mine at different times and refuse to change out parts randomly unless I get an actual code. Even using the Snap On scan tool and the Cylinder Contribution test I have been unable to trace mine.

What type of spark plugs did you use? Did the coils come with new boots and springs? For the vacuum leak check at the rear of the throttle body where the PCV elbow connects - common failure point and is most likely the culprit. I would resolve the vacuum leak before anything else since it can cause rough running as well. I would also recommend cleaning the MAF sensor and the Idle Air Control valve. Both can contribute to the rough running.

 

Thank you for the quick reply ... My father has a f250 v8 that we swears that running higher octane through it will help " keep things cleaner " as for the coils and plugs . I installed the Accel super coils and the E3 plugs ( both recommended to me by a mechanic I know that works for a rail road compainy doing repairs on there ford f350 f450 and f550 ) they came with new boots and spring Ect. I also used a very good amount of that dielectric grease and anti seize as well ... As for the vacuum leak check and cleaning of other parts , no I have not , at least not yet ! But I will be surten to look those over with a fine tooth comb so to speak ... Any recommendation on how to clean the ideal air control valve

 

I would change those plugs to some Motorcraft ones. Haven't heard good things with those in these engines.

Remove, scrub with carb cleaner and toothbrush, and reinstall.

 

Hey Scott thank you for the advise and the info own how to clean the idle air valve !!

I have read some things about these plugs and this motor , but like I said before I was going of a master mechanics info ... That being said do our motors run better on the Motorcraft plug ? Or will a iridium plug work just as well ? I ask because every other motor vechicle I own have iridium plugs in them ... And this is my first American made vechicle ... Everything else I have every owned was German , Japanese , or Italian

 

First off, welcome to FTE!

And secondly you did a great job throwing the whole parts store at the problem, and as we can all see that didn't work out very well. Lots of money was spent, but because a proper diagnosis wasn't done that's all that was accomplished. You did, however, most likely throw out 10 perfectly good ignition coils.

So at this point you really should get to some diagnosis work before further lightening your wallet. These trucks have an OBD-II standard data port but operate under OBD-I standards, which means that misfire codes won't set your check engine light. The only way to tell if there is a code is to have it scanned. While you're in there with a scanner you should look for telltale signs that would help you narrow down the problem. A scanner that can read live data would be able to tell you what your live fuel trims are for each bank, and when you are misfiring you'll see the affected bank begin to run rich because of the non-contributing cylinder pumping air and oxygen through to the exhaust system. That'll cause the oxygen sensor to detect more oxygen than there should be, which will cause that bank to run rich.

Unfortunately these things are nearly braindead when it comes to misfire detection, and it may take a long time before the computer recognizes a problem. But considering how long you've had this problem for there may be codes stored already. If you're interested in a good scan tool most of us around here highly recommend AutoEnginuity® - OBD2 Scan Tool - Professional PC and PDA Diagnostics.

 

+1. These engines are designed to run on 87 octane gasoline; higher octane won't do a thing for you unless your truck is tuned to take advantage of it. You are doing a good job helping the local gas station owner earn a profit though.

 

Crazy, let me begin by saying thank you for the welcome ....

As for my problem , lets start with the spent lot of money ... I am only about $350 into parts which lets face it at 200,000 miles coming up most people are replacing anyway , as for the obd2 scanner .... I have one , a very expensive one that does not only engine codes , but the transmission codes as well as abs and airbags as well .... Now that being said I have scanned this truck everyday since I bought it ... There is nothing there ... If there was I would have stated those codes in my first post ....

Oh and as for the Motorcraft coils that were on the truck ... Yea I still have them and did not throw them away ... < not and idiot > they are being send out to be tested to see if any are bad or not ...

Dude I am not trying to sound like an *** here but lets face it , your post was rather a slap in the face and a little disrespectful ... So now that you have my rebuttal , maybe you can drop the know it all attitude and you know ask questions like civilized human being instead of actin like a arrogant *****

 

I'd like to point out a couple of things. First of all, you came here with a description of your troubles, the steps you have taken until now, and posted that you are at a complete loss for what to do next. You made no mention whatsoever of any work done with a scan tool, and the majority of actions taken were to replace parts that obviously haven't fixed your problem. The fact that your problem still exists after your parts expenditures means that no effective diagnosis was done, and my post was an attempt to help you with that. Over the years I've spent here on FTE I've had the pleasure of getting to know a few mechanics as well as an engineer who spent 20 years at Ford. The one constant theme that they preach is the necessity of a good diagnosis before throwing the parts store at the truck.

Apparently you consider this advice to be disrespectful, and in the same post you berate me with insults. I don't moderate the Excursion forum, but I would suggest that you revisit the guidelines that you agreed to when you created your account here.

 

Only 4 posts in here and you are knocking someone for trying to help you? Come on medic this isn't Iraq, get your act together if you are going to glean anything from this forum.

 

Ok maybe I should have been a little clearer , the wording that you used was uncalled for and in my opinion you were being an *** ( which is not " foul language " ) nor was it my intent to insult you ... But maybe you should reread you posts and maybe you can see where I am coming from ...

A simple " hey have you run a scan tool on it ?" Would have been more then enough to get your opinion in or more info for you input.

I am not on here to try and **** anyone off , I am simply trying to gain more understanding on why she is acting the way she is ...

I do understand you were trying to help , but at the same time you came off a little hostile ... Just my observation ... Again I did not mean to upset you

 

Don't want to step on any toes here . But anti seize can cause misfires . I have seen it many times . Go with factory plugs also , others can cause problems .I have seen some of these with the misfire counters turned off . They will never set a misfire code . I have found misfires with a stehiscope , I KNOW , BS ALERT ! But sometimes you can hear the coil misfire . When placed on top of the coil , it can help if counters are not enabled . It works , trust me !

 

Jwc , dude thank you for the info !! I had no idea about the anti seize could cause a miss fire !!! I have never used it on any of my other vehicles , again it was just something I was told needed to be done so the plugs don't seize to the heads !

Also thank you the clarification on the plugs as well ! As for stepping on toes , your far from it in my opinion ! I am going to throw some serious wrench time to her this weekend and see what I can uncover ..

I did disconnect the battery completely for the night , I have a feeling that the truck threw some codes and some one just erased them before them sold her to me ... I hope by doing this it will cause the computer the throw the codes again so I can see what in gods name is going on with her !!

Tomorrow she is getting the new fuel filter installed and I am going to get the idle air valve out after I get home from duty , and go ahead and get it cleaned and reinstalled and MAF as tdappleman suggested and see what that does ... Then I guess it will be off the the vacuum system ... That is unless I can get some codes out of her ! Again thank you JWC

 

I'm not sure why that rumor keeps being perpetuated, lots of people still advocate doing that. It's because they are confusing the plugs in the 2V heads with those in the early 3V engines, which were put in trucks from '04-present.

The 3V engines had a deep two-piece plug that's known for coming apart when you remove the plug. So to avoid it seizing to the head lots of folks use antiseize when they install them. That problem has never existed in the 2V engines, in fact the opposite is true because if not installed correctly they can be ejected from the head while driving. Applying anti-sieze can in some circumstances act as an insulator which could prevent the circuit from being completed to create the spark.

That's unfortunately a counterproductive step in this process. It takes a certain number of misfires for a code to be set, and by disconnecting the computer you would have cleared that out completely and your PCM will be starting from scratch.

Have you checked your short-term and long-term fuel trims both when it's misfiring and when it's not? Short-term fuel trim adjusts in seconds to a misfiring cylinder, and that would indicate which bank it was on.

 

Crazy , thank you for clarifying that for me ! This morning I had some extra time before I had to be on duty so I pulled the plugs and cleaned all the anti seize off of them as well as cleaned the threads in the heads as well ... I reinstalled them as well as the coils , added so fuel injector cleaner , reconnected to batter , cranked her and she was still acting that there was a miss ... But no where near as much as before ... I let her warm up before even pulling her out of the garage and low and behold I had a check engine light on after she got warmed up !!!! So I grabbed my scan tool an threw it in the truck and bolted to base ... I have found some spare time to plug her up and I got these codes ... P1079 and P3000 ... So it my bank one oxygen sensor bank 1 running lean and random miss fire ...

Now , after I drove her about 15 miles she started acting like a brand new truck !! I have not felt the miss like I did before ... But she does have a random exhaust puff like there is a miss ...

So now that we have these codes maybe we can figure this out !! She is going to the shop on Friday to have the transmition filter and fluid changed and the torque converter swapped out to banks billet torque converter ...

I would really like to get this mapped out and fixed before she goes to the transmission shop ....