98 Ford Expedition EB Edition
5.4L Auto 4x4

Hello gang,

I recently developed a stumble / hesitation in he engine of the above mentioned Expy. Expy ran fine for the most part, but noticed this morning that it was running rough. I figured I may have gotten some bad fuel and with 54 miles left to E, I figured I would through 50.00 bucks in the tank bringing it to just under 3/4 or so.

Anywho, issue continues...it stumbles under load and even in park and neutral. I now have a Scan Gauge II and am showing no codes at all. I went to the parts store and secured a fuel filter and engine oil supplies. Swapped in new fuel filter and did an oil change...problem continues.

Anybody have an idea where to look? My Dad seems to think its either the fuel pump or plugs. Any way to correctly diagnose what the heck is up with the Expy?

 

You need to either wait for a code to be set, or you need to get a hold of a scanner that reads live data. The live data will show you misfire counts per cylinder, so you'll know which one is giving you the problem.

 

You have the very common "mild misfire" problem, usually due to a failing coil, spring and/or plug.

 

Well I took the Expy out for a drive at various loads and speeds and let me say its aggravating as heck now that its missing.

I came back home and tinkered with it for a bit and am still doing the shoulder shrug deal.

I have read things on the net ranging from bad plug, bad coil, bad fuel pump and even clogged cat. I was really hoping I could get a code to pop up and use the ScanGauge to point me in the right direction.

I have to take the Expy on a 800 mile trip here soon, so I really cant sit around and wait too long....looks like Ill be going to a mechanic's shop tomorrow to have a in-depth scan done to see if they can pin point the issue.

 

How many miles? How old are the plugs?

 

Well cant really say on mileage...odometer reads 137k, but there was a discrepencey in the CarFax a year ago showing odometer had 145k on her...I am figuring PO swapped clusters (old roll over style). So I would say there is easily 150k on the Expy.

Have no clue on the plugs as far as age.

I have watched some vids on replacement and seems doable...a PITA but doable.

I just cant afford to throw 8 coils (Motorcraft) and 8 plugs in her and keep fingers crossed.

Oh BTW..for crap and gigs...the vids I saw on Youtube.com showed the plugs had a case down on the lower end surrounding the electrode of the spark plugs. Is there a certain part number available for these...I looked on parts store website and didn't see the exact ones folks were pulling out of their engines. Sorry for the infantile questions....I have limited experience with any ford after 1993.

 

See post #2, then you won't have to buy all eight.

You won't find those plugs in your '98.

 

you need to access the mode 6 data to determine the cylinder with the misfire. if you decide to throw parts at it, i would put my money on either #4 or #8 ignition coil being the culprit.

 

What engine signify those type of plugs? Does it matter if the 5.4L is a Triton?

 

Hmmmm... That's good to know. From all the vids I've see those plugs get stuck and break off. So if I have general run of the mill plugs, do I run a risk of snapping them off in the head? If it's just a straight forward install like other vehicles I am familiar with, I might try and replace them before my trip. Good insurance to say the least.

 

Then get the COPs off eBay. A set of 8 is going for around $70 or so now. Also, if you can ID which cylinder(s) are misfiring, for like $3 each you can buy the rubber boots and replace them on the misfiring ones. For 9 out of 10 misfires the problem is the boot has cracked.

 

Thanks for the replies guys....

I got up early (day off) and planned to take the Expy to the Ford dealer, so they can try and pull some codes/live data. Well low and behold, the Expy is running fine again. I did go by the parts store to buy some degreaser and stuff (working on a 3000GT) and the attendant offered to scan it for me. He found 4 codes (3 ABS/1 ENGINE). The engine code was P1000..nothing else came up.

Im gonna keep my fingers crossed and hope it doesn't return. If it does Ill be sure not to wait to long to get a diagnosis.

I took my old fuel filter and drained it into a 2 liter bottle then strained the dirty fuel I collected...man you wouldn't believe how filty it was...I did the same to my 93 F150 XLT and didn't get 1/4 of the sludge that came out of the Expy's fuel filter.

Ill have to post some pics of the shop towel....wonder if my issues were because of a dirty fuel pump sock, that eventually worked its way clean.....

 

I can only imagine what the bottom of the tank looks like....

 

There was still a ton of sludge sitting on/in the shop towel....I just dumped it because this stuff was sooooo thick it refused to drain any further

 

Hello again troops....

Well I was reading some threads on how to change out COPs and plugs on my engine, so I figured it wouldn't hurt to go ahead and try and swap out a couple so I could get a feel for doing them. Granted, I have changed plugs and ignition components in other vehicles, however this 5.4L Triton design was kind of intimidating.

Anywho, I purchased some double platinum Motorcraft plugs and some new COPs from the parts store. By using this forum, I successfully swapped out #'s 1 and 2 without any major difficulty, as for they seem to be the easiest. I was shocked on how much sand and little rocks were down in the spark plug wells.

After I completed the install, buttoned everything back up and took her for a ride. Wouldn't you believe that it was running worse than before. I was like what the heck. I was heading to the parts store to recycle some oil so I figured I would have them scan it for me (last time I headed that way, Expy stopped acting up).

Well I take care of business and the parts guy scans my Expy. I had like 6 codes now. 4 were ABS junk and the other two were P0304 (misfire on 4) and I don't recall identifier on other code. He mentioned something about computer not being able to run full check on itself. He further mentioned it could be a sign that the PCM was dying.

So now I know for sure I got a misfire on 4, which I will attempt to fix tomorrow or this coming weekend (cash is tight).

As far as the other code where he said the PCM not being able to check itself, have you guys heard of this before? Is this something I should be concerned with immediately? Maybe this is why my scan gauge 2 reads "Not Ready" on the main screen. SG2 still shows live data, but doesn't pull codes for crap (at least the way the instruction manual says it should)