Hello everyone! I'm new here and seeking some help.

My 2006 5.4 Expedition is hard to start and idles rough. The codes say cylinder 2 is running rich and misfiring. I replaced the plugs and it was good for a week, but then went back.

My mechanic says the pressure in the fuel lines is bleeding out when the engine isn't running and he wants to replace the fuel pump, but can't find one for sale. I found the pump online and am considering changing it myself.

Any ideas? Similar experiences? Any help would be GREATLY appreciated. Thanks, all!

-Jay

 

do you mean running rich on bank 2? the hard start could be the fuel pressure draining back because of the pump

 

Then lets be thankful this isn't a mental health forum.

These two tidbits of information should clue your mechanic into the #2 cylinder having a leaking fuel injector. It explains both the cylinder running rich and the loss of fuel pressure as the truck sits.

 

Thanks for the quick replies! It is cylinder #2, not bank 2 that's rich. And I was thinking the same thing about the hard start. Like it has to build up pressure to get going.

I'm going to check the injector tomorrow. I'll let you know what I find. Thanks again, guys!

-Jay

 

If the piston is in the right place the fuel leak could cause hydrolock requiring spark plug removal to clear the problem with the possibility of reoccuring. Replace the injector, it's not a big job.

 

wow it's a no brainer for just one cylinder to be rich( by looking at the plugs) and there to be a loss of fuel pressure it has to be a leaking fuel injector,

have you checked your oil to see if the fuel is leaking down past your rings you'll need to get that changed also when you first start it up is there a big black puff of smoke

 

Ok, I went to Autozone and double-checked the codes. I got a different result than what my mechanic had originally told me.

I got:
P0175-BANK 2 is rich OR lean
P0300-Random misfires
P0306-Misfire in #6

I know. Seems completely different than what I said before. Sorry about that! From this it seems to me that it's not just a fuel injector, but something more serious. Fuel pump after all?

Thanks again for all of your help with this, guys. This is my dad's truck and I'm trying to save him some money since his budget is pretty tight right now. He doesn't have the time to mess around with it since he works. I still have some free time because I'm on a break from school and he's borrow my truck in the mean time. Thanks again!

 

since this is your dad's truck are you sure it's not an 05, there is a recall that extends the warranty for the fuel injectors to 11 years or 120,000 miles and the codes set for the recall are the same that you have

oh and p0175 is rich only

 

Didn't know that about P0175. It's definitely an 06, though. Just checked the VIN.

 

ok well if you pull the rail up on the driver side and make sure your injectors stay in the rails ( zip ties work well) and put a small container under each injector to catch any fuel( becareful this is a fire hazard) then have someone cylcle the key to on NOT START a few times if the injector is leaking it will spray fluid otherwise it will hold the fluid and not spray all over the place

if it doesn't leak replace the coil, if it does leak replace the injector

BECAREFUL

 

Each time (cylinders 2 & 6) you got a rich code, so perhaps you're having issues with multiple injectors that come and go at different times with the different cylinders.

 

Let's step back and take a breath.

As far as I know there is no code to indicate a cylinder is rich.

Ah! And did your mechanic come to this conclusion by hooking up his trusty fuel pressure gauge and watch the dial after shutting the engine off to see if, or how quickly the fuel pressure dropped off?

Oh. And did your mechanic say how he determined the fuel pump was the cause of the 'bleed out' ?

You can turn the ignition key to on (not to crank) for a few seconds, and then to off, repeat two or three time. That will cycle the fuel pump so the fuel line should be up to pressure. Then turn the ignition key all the way to crank to see if it starts any better. This would tell you if low fuel pressure is causing the hard start.

IIRC, P0175 = Bank 2 is RICH. You can confirm this by looking at the Bank 2's LTFT (Long Term Fuel Trim). IF it is negative and in the 25% to 35% range, bank 2 is running rich. The PCM will reduce the injector on time of all bank 2 injectors to try and compensate, which will lean out all the cylinders on bank 2, which in turn could cause the P0300 random misfires.

I'd also look at the LTFT for Bank 1. If it is negative, but maybe not as high as bank 2, you might take a look at the fuel pressure regulator and its vacuum hose. (Does this model year use a fuel rail pressure sensor?) Also, look at the EVAP canister purge valve. It could be leaking when the cansiter is loaded and running bank 2 rich if the cansiter's vacuum source is on the bank 2 side of the intake manifold.

Also, as Fordtech08 suggested, you might want to pull all the plugs, keeping them in order and see if you can verify any pattern to the richness.

Keep us posted on your progress.

 

Got a minute to discuss this? I ask because I have this Dodge van with a P300 code that is driving me nuts because I can't get solve it. It's also got P0301, P0303, and P0305 for codes. It's a V6 and 1, 3, & 5 are all on the driver's side. Cylinders 2, 4, & 6 all run perfect. Could what you're describing above be what I need to pursue in order to solve this problem?

 

I'm only guessing, but I don't think your issue is the same, as you don't have any code indicating a rich or lean bank.
But the misfiring on bank 1 (depending on how bad the misfire is - is the CEL flashing?) would pass unused O2 out the exhaust and the O2 sensor would interpret that as bank 1 being "too lean".
Is there anything common to cyl 1/3/5? Like are they all fired by the same coil? Maybe a intake vacuum leak that only effects bank 1 could cause 1/3/5 to be too lean to get good ignition of the fuel?

Again, looking at the LTFT of each bank my indicate where the problem might be. (There usually is a 3X3 aray of cells (9 values) of fuel trim for each bank (think 3 columns for low, medium, and high rpm by 3 rows for light, medium, heavy load.)
If you look at the LTFT while at idle and the trim is positive and say <15% (PCM displays the low rpm/light load cell), and then you run the rpms up to say 2500 rpms (now the PCM displays the medium rpm/light load cell) and the trim drops back to say 0-5%, thats a good indication of a vacuum leak for that bank, since as the rpms go up more air enters through the throttle body and the same amount enters through the vacuum leak. In other words, the vacuum leak has less effect at higher rpms while still under light load.

 

Actually, I think your problem is that it's a Dodge