I am at my wit's end, and need help. I have a 99 Expedition 5.4 liter "L" code, and found out from a transmission shop that one injector did not work. I ended up replacing all injectors with Accel #21 injectors, and the missing cylinder went away. There is another problem I found out....
When driving slowly at 1500-1800 RPM in 1st gear, the truck sounds like it sputters (ie not enough fuel or like a choke problem). Looking at the tail pipe, there are no tell-tale signs of a rich mixture. This problem also shows up at the same RPM band on higher gears and being light on the gas petal.
I put a computer on the OBDII port and there are NO engine codes reported.
I don't want to take it to a dealer, but I don't want a mechanic to do a "hunt and try" with a big bill at the end.
I would pull the spark plugs since you have went up in injector size. I really would not think just going up to 21s over 19s would be a big deal but the parameters my have been exceeded in the fuel management.
Had a new thought, did you unplug the battery to reset the parameters?
Good thought. When the mechanics at the transmission shop were diagnosing it (it wasn't the tranny - Thank God!!) they started going down the path of either the coil on plug (cop) route...they even switched coils around. While there, I had them change out the plugs. This was 3-4 months ago. They said the coils were fine, but there was no fuel being delivered to cylinder #7, ergo the injector. I decided that I would swap out ALL the injectors instead of buying one injector for 100 bucks, and make sure I had new ones all around - easy to do by the way. (Truck has 110K miles and previous owner aka. bro in law did minimal maintenance).
Each of these in my mind, could potentially cause this condition but here is my logic - please advise if I missed it:
1)Would a sensor somewhere cause this (ie o2, mass airflow, etc)? Maybe, but the sensor would be either like a light switch (all on- working; all off-broken and OBD lit up) , or if it is variable voltage, would be consistent at a certain voltage during operation. Question: Which sensors are variable voltage?
2)Could it be a vaccuum line going bad? Based on other forum postings, there is a vaccuum issue with the 5.4 if a line goes bad, BUT the MIL light goes on. Mine is off. Plus, a visual inspection of the engine lines looks pretty good with all the lines.
3)Fuel Pump intermmitent? Could the fuel pump either have an intermmitent issue, OR could it be that a #21 injector require more delivery? According to performance shops and manufacturers, the 5.4 can take up to a #30 injector but once you get at #24, you need to boost fuel pressure to match delivery. The #21 injectors are listed as a direct replacement with NO ECU or Mass Airflow adjustements. As an aside, the fuel rails were clean inside with no blockage.
4)Electrical wire/part going somewhere? Just throwing this out there, but could it be that wiring is the culprit? Why then, would it only be at 1200-1800 RPM in all gears? Not suspecting this that much as this would not be consistent with the symptom.
Any ideas? All comments cheerfully accepted!! (and NO I can not get a new truck!) ;-)
Interesting that the COP might be it, and the prices not bad either for a set. The only thing was the mechanics said that they appeared to be just fine. Do they start dying after 100K miles and someting that needs replacing periodically?
Also, the MAF would be a consideration, but on visual inspection was clean and looked real good. As for the fuel filter, on the Expedition, not sure I found one (might have not located it yet). Where would it be located on a 1999? I will replace that first, as clean fuel is ALWAYS a preferred thing to have.
Thanks for the Picture. I will check out the fuel filter and replace it. If that does not improve things, I will suspect that it is not a fuel delivery issue and go to a COP replacement. Is there any merit in getting a higher voltage COP from places like Summit or Jegs?
Thanks all for the suggestions.... This is what has been done since my last posting (sorry for the delay).
- I put Sea Foam (I think that is what it is called) fuel conditioner and cleaner. Normally I use Lucas, but the guy at Advanced said that many mechanics use Sea Foam. Interesting stuff!
- After driving a while (read tankful), I replaced my fuel filter. WHEW!!! what a Bear! Those spring connectors are easy once you do it, but if you dont, the tool is inserted, and you push on the filter, the connector, etc..... then you remember....keep it simple stupid (KISS principle). Click click, it was off, inserted the new one and the Truck performs a bit better. MUCH less sputter. Interestingly, what came out of the old filter was gunky, like half jello half red'ish in color.
Results: Performs much better.....but, there is a *little* bit of the sputtering left, but not so much as it would sound like a "miss" or a starvation problem.
Budget in mind, I will hold off the COP replacements, for now. Thanks all for the eBay connections to the discount parts places! Good prices...just can't put 100 bucks into the truck yet.