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5.0 lean codes a mile or so after restarting... otherwise fine!

Discussion in 'Stock 1995 - 2001 Explorers' started by Ol' Mountaineer, June 26, 2019.

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  1. Ol' Mountaineer

    Ol' Mountaineer New Member

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    Never mind! I just ordered 8 injectors from Rock Auto.... no need to test the old ones. Happy 4th everyone!
     
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  3. Ol' Mountaineer

    Ol' Mountaineer New Member

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    Hello fellows!

    Still "under the hood" here.

    The new injectors are installed. Rail fuel pressure ramps up to 58psi with a few key turns after standing overnight and stays at 58 with engine running, starts slowly dropping on shutdown. No gas leaks found after following line back to the tank. Maybe 58 is close enough.

    Question: Where is the gas going when the pressure drops if not into the engine through a leaky injector? Through vacuum line on fuel pressure damper?

    Still running lean on bank 1 and missing in cylinder #3. Will try to patch exhaust manifold leak (which I can hear but not see!) with Quiksteel Thermosteel next.

    Suppose I could try some valve cleaner and a vacuum line Seafoam treatment...

    Your thoughts are always appreciated!
     
  4. fast_dave

    fast_dave Active Member

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    @Ol' Mountaineer

    Let's try and solve the miss on Cyl 3

    It's pretty tight back in Cyl 3 area due to A/C components.

    If the spark plug endured any extreme side pressure when torqued down, the ceramic could have cracked.

    Also, the plug wire can be difficult to seat on the plug "nub". Check that it is truly secure.

    If both of those conditions check out, try swapping around the #3 wire (to see if the miss moves).

    Report back!
     
  5. Ol' Mountaineer

    Ol' Mountaineer New Member

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    @fast_dave

    Checked the spark plug on cylinder 3, the cap was off! This is the second time I found this, and I'm pretty sure I secured it well last time. I know the manifold leak is on the underside of the manifold, where it attaches to the cyl 3 exhaust port... it blows a lot of hot air right around the plug. Also, the wire is new, but the 2 piece metal shroud was split open a bit where it is crimped... expansion from the exhaust heat?

    I reseated the shroud and reinstalled the wire. The plug itself was installed carefully... I've cracked one before, so I know.

    It's hard to get to the leak, but I plan on attempting to seal it with this Thermosteel stuff... haven't used it before... and am sure I can't clean the surface well... but there's not a lot of options for a cheap repair.
     
  6. 410Fortune

    410Fortune River season Staff Member Moderator

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    dorman exhaust manifolds are a cheap repair, they are pretty decent for the $$$ and with the right gaskets it will fix that leak
    It kind of a pita to replace the manifolds on the 5.0, but not terrible, I mean it can be a good way to spend a weekend. Most times i can do both manifolds in a day working slowly and making everything seal up right

    Now that cyl 3 is likely firing again lets see how she runs and if the lean bank clears up
     
  7. Ol' Mountaineer

    Ol' Mountaineer New Member

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    Boy do I wish I had good news! Get a drink, long story...

    Headed out today (after adding a bit of valve cleaner to the tank) to find some heat shielding to better protect plug on cyl 3. As I go along all seems smooth, albeit with the chug, chug, chug sound of the exhaust leak blowing at the #3 plug. Couple miles along chug, chug, chug stops and I think "heat musta sealed the leak a bit". But I get out and look.... the sound stopped because the plug wire was off again. The thin metal shielding just came apart... so I fiddled it more or less back into shape and put it back on the plug and continued along.

    Another mile or so into town and I got pulled over. I explained that I was going directly for an inspection after doing a lot of expensive work on it and he let me go. Went and failed inspection 'cause the computer wasn't reset.... but at least I got current paperwork.

    Ok, so now I'm thinking maybe I can drive around a little more to reset the computer... mile later plug comes off. Put it back on head to NAPA. They've no shielding. And now I'm smelling gas.

    I see nothing unusual in the engine compartment. Constant sniffing says there's gas there. Not along the fuel rail, not under the car, not at the tailpipe, not around the tank. Hmmm.

    I decide to go to the other parts place in town... nervously, as I'm still smelling gas. It's about a mile and a half. Pull in and park and there's some white smoke from under the hood. Under the vehicle, the rear seal is dripping oil onto the cat. I take a chance and open the hood. Smelling gas and see some oil seeping from the fill tube gasket up the outside of the tube. (A clue? Oil pressure too high?) Go into Advance Auto and borrow a fire extinguisher, just in case. As car cools I inspect the small pools underneath. The oil seems thin, I suspect gas mixed in has thinned it, negating the effects of Barr's Main Seal Stop Leak. There seems to be a small pool of water too, but that might be from someone else.

    Decide it's time to tow it to the shop for diagnosis. While waiting around I find some new moisture under the fuel rail on bank 1. Could the Schrader valve be leaking? Maybe.

    We need to know where the gas goes when the fuel pressure drops stat! And, am I looking at a cyl #3 valve job?

    The wife picked me up and brought me home. I have an hour or so before the tow guy arrives to decide whether to tow to the shop or home. As always, your input is appreciated.

    Kind regards,
    Bob

    ps: symptom recap:
    fuel pressure goes to 58 and drops too fast on shutdown
    smell gas
    leak at cyl 3 exhaust
    #3 plug wire keeps popping off
    oil seems thin, may have gas mixed in (oil and oil filter are new)
     
  8. CDW6212R

    CDW6212R Hauls the mail. Elite Explorer

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    Fuel can get into the oil if an injector is leaking very badly, or the PCM is commanding a large amount too much(excessive lean condition etc).

    But the liquid outside of the engine is an immediate concern. How sure are you that there is no fuel on the intake under the fuel rails? The injectors all have two o-rings, and it's best to not reuse them for fear of a leak. A smell of gas is possible from the rear of the car, from the charcoal canister which is designed to capture fuel vapors to store, and return to engine by the aluminum hard line that leads to the front/solenoid, to the engine.

    Try to narrow down where the fuel smell is coming from, near the tank, or behind that a little, or near/under the battery, or from the engine itself(top-injectors).
     
  9. Ol' Mountaineer

    Ol' Mountaineer New Member

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    @CDW6212R

    I'm not with the car now, but I replaced all the injectors with new, all with new o-rings. On removal, the old cylinder 3 injector was missing the brown rubbery bit at the nozzle end... I looked for it but assume it was eaten by the engine. No traces of it remained, so I installed the new one. Used a bit of olive oil on the new o-rings to help them seat. When all injectors were buttoned down under the rails, I did a pressure test to make sure none were leaking. A couple key turns and 58psi. Dropped down to maybe 52 on key off, then slowly drops off from there. But it appeared that the injectors were not leaking so I replaced the plenum.

    However, last I looked (in Advance Auto's parking lot) I had the impression that there was fresh fuel on the intake under the bank 1 rail, looked like maybe the schrader valve as the injectors (that I could see) looked dry around their bases.
     
  10. Ol' Mountaineer

    Ol' Mountaineer New Member

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    When I sniffed around at NAPA, it seemed more concentrated near/under the battery.... what's over there? The lines looked fine.
     
  11. koda2000

    koda2000 Explorer Addict

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    The emissions evaporation purge valve and its hoses.
     
  12. CDW6212R

    CDW6212R Hauls the mail. Elite Explorer

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    If the fuel smell is not raw fuel on the intake, then it's likely from the vent/capture system and not immediately critical to not drive the truck. The emissions hoses and lines, plus purge valve are fairly secure but old age and work around them can end up with a leakage of vapor etc.

    First be sure the engine area(intake) is not wet at all, if there is any gas, likely you will be R&Ring the fuel rail again. Check the fuel pressure buffer(I forgot what it's called) device on the rail, be sure the vacuum hose is not wet inside.
     
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  13. Ol' Mountaineer

    Ol' Mountaineer New Member

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    @koda2000

    Thanks. I never really took the time to figure that out. I can't run out and check now, but is that where the hose from the fuel pressure buffer goes?

    @CDW6212R

    R&Ring again certainly a possibility. Now the beast is at the local shop. Thought it best to tow it somewhere, rather than try to drive it, and if I had it towed home I might be towing it twice. My concern is where is the fuel going, and have I burnt a valve or a hole in cyl 3 piston. Pretty sure gas is getting into the oil. (Bad electrics not shutting down injector #3?) Not sure what my next step is... certainly to look for gas in the pressure buffer vacuum hose...cylinder pressure check maybe... I guess I may have to lift the plenum again... I'll have a think and report back soon.

    It's possible the white smoke was just residual coolant from under the bank 1 fuel rail. There was some that escaped when the hoses to the plenum were disconnected. Didn't get it all cleaned off before heading out this morning. Between that, the sight of oil bubbling up through the fill tube gasket (never saw that before!), the smell of gas, the exhaust leak, the #3 spark plug wire constantly coming off, and the dripping of (fuel impregnated?) oil onto the hot cat... what a day.

    Gotta say though, up to that point, the car seemed to run pretty smoothly while the plug wire was attached.

    Thanks again for sticking with me guys.
     
  14. CDW6212R

    CDW6212R Hauls the mail. Elite Explorer

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    Keep a good thought Bob, and take a break once in a while, to not let too many symptoms get you down. Most things are manageable by yourself with some effort.

    A fuel leakage is a different animal though, not to be poked at randomly etc. I'm sure the shop you took it to will be careful hunting for a potential leak, we hope so. Get the fluids under control, and then check on things like with a compression test etc.
     
  15. 410Fortune

    410Fortune River season Staff Member Moderator

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    raw fuel leaking and you just replaced injectors = something went wrong with injector install
    it is very easy to pinch a O ring or smash an injector seat and get a leak
    Raw fuel dripping down the back of the block, smart choice not to drive it! My stepson almost burned down the forest after doing upper intake and fuel rail he hit the starter on a ranger and it burst into flames...luckily we had extinguishers close by. Guess who pressurizes the system and checks for leaks before he bumps the starter? Ill give you one guess

    Let us know what comes of this
    5.0 are super tough engines, I doubt you burnt up any valves just yet.....
     
  16. Ol' Mountaineer

    Ol' Mountaineer New Member

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    Yeah, I'm a little concerned the #4 injector could have loosened up. It was more trouble to install than the others. I'm pretty thorough and careful though, did a pressure check before remounting the plenum... all was fine then.

    And shortly before I had it towed the Mounty was running pretty smoothly while idling at the inspection place.

    So the plan is this: I'll have the shop install a new bank 1 exhaust manifold (Dorman 674-329, new from eBay, under $60 inc tax and shipping). Shop quoted $150 for the installation, I'll supply the part(s). That's pretty inexpensive. Maybe these vehicles can run forever with an exhaust leak, but this particular leak is pulsing superheated exhaust onto the #3 spark plug cap, heating and vibrating it to the extent that the cap won't stay on the plug for much more than a mile. It blew the metal shielding right off the new wire. Plus, it'll be great to finally get rid of that noise! I haven't found a set of manifold studs, not knowing what size is correct, maybe someone could point me to some?

    The shop will also diagnose the fuel pressure drop. I'm now suspecting the fuel pulse regulator. Easy enough to check. If it is failing, couldn't it send fuel into the crankcase via the vacuum line? At this point I'm fairly certain that fuel is mixing with the oil... wouldn't take too much to thin 5qts of oil and lower its boiling point. I saw oil boiling out of the oil fill tube gasket. And it completely negated any effect Barr's Main Seal additive might have had.

    I forgot to ask the shop for a quote, but maybe I'll get the rear main bearing done as well. Not like I'm made of money. Just not happy with fuel and oil mix raining on a hot cat. If it's too much for now, I guess I'll just drain my "fresh" oil and renew (with Barr's).

    This will take about a week now, 'cause the guy who'll do the work went on vacation yesterday.

    In the meanwhile, happy motoring fellows!
     
  17. CDW6212R

    CDW6212R Hauls the mail. Elite Explorer

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    Good luck with the plan, expect to live with the existing bearings and seals etc. Hopefully no harm was done to the bearings etc, just keep a close eye on the oil regularly for a long while, every day or two. Replace the oil with new synthetic, and the filter.

    If that rail pulse reducing device is leaking fuel by the vacuum line, it might be hard to find fuel in the line. It could pass a lot of gas and not obviously show wet gasoline in the vacuum line. So track down the leak wherever it is, and then see if the fuel pressure becomes closer to what's expected, and see how it runs.
     
  18. Ol' Mountaineer

    Ol' Mountaineer New Member

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    Ok fellers, here's the exciting conclusion...

    #1: I apparently crushed an O ring on the cylinder 4 injector when I replaced the injectors. (Hat tip to 410!) It held when I pressure tested the rail, before replacing the plenum, but started leaking down the back of the block after about 5 miles. The thinned oil I saw dripping on the cat was actually gas that picked up oil from the leaky rear main seal... thankfully was not mixed in the crank case. Also thankfully did not ignite!
    #2: The white smoke was just a bit of coolant burning off under the fuel rail. No biggie.
    #3: The pulsing of hot exhaust gas directly onto spark plug #3 was the cause of missing and lean conditions. New passenger side exhaust manifold was about $60 on eBay and $175 to install, cleared it right up. (Glad the shop did the job, as two studs broke in the process.) I guess you can't drive forever with an exhaust manifold leak.
    #4: Turns out I needed a new DPFE sensor as well... still had the original with 187k+ miles.

    The Mountaineer is now purring like a kitten, I'm getting 19-21MPG again, and I think for the first time since I bought this truck I was able to pass inspection confident that CEL would stay dark. Should be good for a while now. Gonna live with the rear main seal as is, and Barr's in the oil.

    Thanks to all.
     
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  19. CDW6212R

    CDW6212R Hauls the mail. Elite Explorer

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    Excellent, good job working through the issues one at a time. Thanks for the update.
     

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