Bluegrass.
I wentback and read this entire thread twice. You helped with the flooded condition by telling me what to do to solve it And I thank you. But with this truck acting like it has a misfire condition while warm and under a load, oh yeah it has not thrown any new codes, you have done nothing beat down my thought process, honestly tell me what to do to solve it then and if you want to leave the thread, then leave. I came here to provide you all with a problem and seek out you all for a solution. Not to be reminded of my mistakes.

 

If I understand correctly, you need to know which is #1 cylinder? Or how they are ordered on this engine. Here is a pic.... 1-4 is on passenger side 5-8 on driver side, complete with firing order below:

 

David, I know this may sound completely out there but I worked on an F-250 with the 6.8 that was shuddering and falling on its face warmed up and I found two problems: first the fuel pump screen in the tank was plugged. It had plenty of pressure when the truck was at idle, but when it warmed up the pump started by-passing and the pressure went way down. Check it while you're warm and running, there is a tester that you should be able to use while out on the road. maybe your local partstore has one for lend, and make sure you're not losing the fuel pressure. Second, check your mass airflow sensor. It rarely tells on itself through PCM codes (at least in my experience) and it causes the shaking and bad running. I think the local part's stores can test it (sometimes lol). Once the fuel pump was fixed, the truck ran much better but idled rough. with a new mass airflow it ran good as new. After all you've done to help your friend, hopefully it's something simple and cheap. Good luck

 

Cuba = thats what im talking about. Im an engineer by trade so drawings and diagrams is something i understand very clearly.

Greg= please see the picks below. tonight I will get a reading for fuel pressure when its warm and while driving. also i will clean the mass sensor. and post the results.










based on these vac readings. i believe that if there was a vac leak at one point; it has now been resolved. I work primaly on buicks 3.8 L and dodge 3.3 L. Since this is my first ford in a long time. Do you all agree that i have proper vacuum and fuel pressure on this 5.4L engine?

I atempted to flush the heater core and WOW that thing was clogged pretty bad. I got it to flow and blow hot air. So heres my question. i am considering letting the flushing product sit in the heater core overnight and all day staring tonight. do you know of anyone every doing this with little to no damage to the core?

 

I don't think it does much just letting it sit in there. I usually leave it in there for however many days it takes for me to drive the vehicle four to six hours. Check the directions on your flush container.

And I can not recommend enough to pull one of the block drain plugs when you flush it out of there.

(Just an FYI, but when I acquired my Navigator I used a flush product as described above. But after opening the radiator drain and block drain to flush it out I had to repeat the process (fill with water, run engine up to operating temp, cool down, open radiator drain and block drain) NINE times before the block water came out clean!!! Only then did I put the antifreeze in............but then I'm kinda fussy.

 

That works David. The vacuum seems about right for a stock 5.4. I agree with pdq, just letting it sit won't do a whole lot. It shouldn't damage anything but won't clean it as well as you'd hope. You're best bet would be to leave it in as long as you're tinkering with the other avenues you're exploring with the truck and flush it then. Definetly use the block drains if you can access them easily. It helps drain a lot of stuff out of the 5.4 blocks that you just can't get out of the petcock.

 

Comment: on these electronic controlled systems a vacuum gauge reading will not be anywhere near as sensitive as the Oxygen sensors in detecting an air leak.
A gauge would only pick up a major leak and likely affect idle to a major extent.
Good luck.

 

I broke it down as basic as I could, not only for you but for whomever has similar issues. Many guests, and including members aren't as well rehearsed in turning wrenches as you or I. I apologize if I sound redundant at times.

what I found to work better than the "flush" like prestone's, is CLR cleaner (or equivalent). It's for calcium, lime, and rust deposits typically used in cleaning bathroom (shower heads, toilet, etc) or kitchen items. You may like those results more, and only time I ever seen issues in it's use was when core or radiator was already on it's way out and "seeping" in places.

 

You I agree with all three of you. In darts. Thats a hat trick. Nice. That O2 came in to question a while back. The lady who owns the truck found the auto zone code print out she recieved back when this thing strated messing up and 02 Sensor was listed a possibility. That would have been nice to have seen early on.

saturday is the day im going to play WACK A COIL. by swapping one at a time to see if I can located a bad coil. And try to fix this misfiring action. Its to dark and cold durning the week to mess with that after work.

Messing with drain plugs worries me. It was a pain in the rear to put the drain plug back in the crossover.i thought for awhile it wasnt going to go back in.

it funny you recommend CLR. because thats what I have been using for to nights in a row.i have been isolated the core by diconnection both hoses and supplying clr directly to the core and letting it sit fo about 30 mins each time.

 

OK, I read this entire post and I applaud what you are doing and your efforts to get it done. I am not sure that I can remember Everything that you posted, but a couple of things come to mind. I know that you said the wires to the coils and injectors were not long enough to get crossed up. All I can say is that I have heard that one before. You might be surprised how wire harnesses can be twisted and hooked up wrong. In the absence of an automotive scope, I would do whatever is necessary to get a wiring diagram and verify that the harnesses are hooked up correctly as a single mistake here could easily be your stumbling/misfire problem. Look at the wire color from the injectors and coils to the PCM and make sure that they ALL are correct. Be careful with identifying which cylinder is misfiring based on scanner information. Since the PCM uses changes in crankshaft rpm to identify which cylinder is misfiring, it can sometimes identify the incorrect cylinder, depending on acceleration/deceleration at the time of the misfire. In summary, I would make SURE that all of the wiring harnesses were correct BEFORE spending a lot of time swapping coils around.
Good Luck with it. Hope you get it working soon.

 

Ok radiater flush complete. As for the cop swap. I preformed that on the cylinders 1,2 & 5,6 on the left and right banks I used 4 cop' s from a junk yard. My test drive usually produced this misfire condition after about 4 miles. Now the misfire condition did not occur until I went about 15- 20 miles. I was really happy at 10 miles but that quickly turned to sadness . So What does this tell us?a mis fire condition at about 4-5 miles trip, swapped 4 COPS now misfire condition at about 15-20 mile trip.

ok second test drive.15 minutes after the first. My fuel pressure started at 36 and then dropped to 21 at about.2 miles into the drive and remained stead at 21.there was no engine shuttering at/ with acceleration.at 9.5 miles going up hill it shuttered briefly. Then went away. One mile later it shutter again going up hill only. At about 13 miles into the trip it shutter up every small grade and when .accelerating on level ground. My fuel pressure never changed durning the shuttering/ stumbling, it was still at twenty.when I got back home. I turned it off and waited about 5 mins and read the fuel pressure it was back at 36 Someone asked about this I cant remember who. But here are the fuel pressure results while driving.

 

Dave, I'm sure your quite accurate with the reports.
Here is what is happening based on long time experience.
At a drive condition of cruising in OD the EGR is called into operation by the program.
This sets up conditions as follows.
1. fuel is cut back.
2. ignition timing is advanced.
3. exhaust gas is metered into the intake.
4. air/ fuel ratios goes very lean to levels of 22 to 1 or more for all cylinders.
.
The results of all this under normal no fault conditions is transparent to the driver by design.
.
However; very lean A/F requires higher coil voltages to fire the lean mixtures.
.
Fault: I one or more coils have low voltage output during these specific conditions cylinder misfire results such that you feel is as anywhere from a shudder to outright jerking.
If the shudder goes away after down shifting it tells you the EGR has closed and A/F ratio has gone richer and back to about 14 to 1 +/- depending o how much load the motor is given.
The richer mixture is easier to fire by an offending coil that still has enough out put to fire reliably under richer conditions.
.
Why no code and CEL; The PCM stores the misfires in a counter register.
Since the fault is not a hard or permanent fault, a code is not set because the PCM cancels it in it's 'fault' register after it is no longer present but is still in the cylinder misfire register. These are two different registers.
.
. Bottom line is there are one or more coils with shorted turns that show under the specific driving conditions. What you did was play the game of what Cup is the Bean under?
By moving coils you move the trouble until eventually you begin to see which one it is. To many chances of introducing problems from all the moves.
.
Lastly the fuel pressure dropping to 20 psi 'greatly' aggravates the condition even more by leaning the mixture even more.
.
From all this it appears there are two problems causing the results you are seeing.
A. Coils.
B. Fuel supply issue.
If a Scanner were used to look at the cylinder misfire monitors you will be able to tell which coil or coils are the offenders and prevent all the on going test drives except the final test to be sure all issue have been solved.
I hope this offers you a solid technical chain of events, there results and how to deal with it.
Good luck.

 

I have thought about buying a good good scan tool for the past year. The wife cant say she didn't know; when i walk in with it . Im unsure of what brand to get. What would you recommend for a home mechanic with a little sense.. What do you think of things bought at harbor freight. I like lowes kobalt line, but cant remeber if I have ever seen a scan tool there. These two places are open on sunday. What ever I get I want it to read more then just the powertrain.

 

Well, a Scanner to read much more than the power train tends to get quite expensive for the use it might get.
Go to SEARS and look at the model 20890 or higher.
There are other makes that will do the same but the problem is you cannot tell from the package or box what one will do without a lot of research or someone who has experience with another unit..
Then after you get one you have a learning curve how to use it, interpret the live and stored data for the specific engine.
Good luck.

 

Ok It has been fixed and delivered today. I want to thank all of you that helped out on this. Here was what I believe was the problem.

I went and bought a cen-tech 60690 scan toool today. When I plugged in I got two pending, not stored codes, p0355 and p1401, p0355 was a connection error to cylinder 5. The clip that secures the coil to the wire harness had broken. There was no snap sound when I plugged it back in. I am assuming that after a drive, the engine vibration, vibrated it lose enough to cause a problem , but not lose enough to visually see. When I got the coils from the junkyard I also got the connectors.THANK GOD I DID THAT. Anyway fixed it. But still misfire condition remained after a test drive. I used my new toy and pinned it down to cylinder #3. When I pulled the COP. I noticed the tip was wet, as you know I flushed the core. Anyway I shot some air in the plug port and coolent came out. Not alot just a little. So I took all COPS OUT FOR cylinders 1,2,3,4 (heater hose side) and dried out the plug ports. They all had a small amount of fluid in them. After the dry out I drove it and.
re checked the codes they were gone. Drove it to her 72 miles and no problems. So it was a small amount of water in the plug holes and a broken coil harrness connection. The plug connection I get, plug, unplugg.it happens, but how would fluid get past new plug boots. Strange.. again thank you all so much for the help.