2013 6.8l V10 Low Idle and Surging - Page 4

arctictraveller · 03-30-2017, 10:24 AM

Have you tried spraying carb cleaner around all the hoses to eliminate the possibility of a vacuum leak?

Flux · 03-30-2017, 10:33 AM

Quote:

Originally Posted by arctictraveller

Have you tried spraying carb cleaner around all the hoses to eliminate the possibility of a vacuum leak?

I did. Nothing happened. Kind of wish it did as that would make it much easier to figure out!

One thing I did not think of until Scott mentioned fuel pressure etc is that I had a new fuel tank built during the conversion. Hopefully it's nothing to do with that, but it really could only be the pump/sending unit at that point. But I will take Scott's (and everyone else's) good advice and backtrack to the obvious little things and check the fuel pressure at the rail.

I should probably also check the alternator output volts just in case.

So here's my list:

Already cleaned the MAF with the correct spray.
Replace EGR and Hose
Replace fuel filter
If still running funny, then it's fuel pressure check time.

If I get to this level, then I may have to get my mechanic on it so I am not just throwing parts at it. I do like the challenge and the learning experience though.

REDOVAL · 03-30-2017, 11:36 AM

Quote:

Originally Posted by Flux

I did. Nothing happened. Kind of wish it did as that would make it much easier to figure out!

One thing I did not think of until Scott mentioned fuel pressure etc is that I had a new fuel tank built during the conversion. Hopefully it's nothing to do with that, but it really could only be the pump/sending unit at that point. But I will take Scott's (and everyone else's) good advice and backtrack to the obvious little things and check the fuel pressure at the rail.

I should probably also check the alternator output volts just in case.

So here's my list:

Already cleaned the MAF with the correct spray.
Replace EGR and Hose
Replace fuel filter
If still running funny, then it's fuel pressure check time.

If I get to this level, then I may have to get my mechanic on it so I am not just throwing parts at it. I do like the challenge and the learning experience though.

Flux,

If you want to make a drive to Lomita I could lend a hand in assessing the issue. It does seem odd though to have an engine that runs nicely on the top end but won't idle right. You may want to have a look at the IAC; they tend to get dirty and stick on some other Ford engines. I believe the answer is no, but does yours have the plastic upper intake manifold?

Scott

Flux · 03-30-2017, 01:18 PM

Scott,

Thanks very much for the offer Scott and I may take you up on it if I can't track this down. Not sure about the manifold.

One thing I think I know is that there is no IAC on the later models. From pics I have seen of the PCV tube on older models, mine is completely different again as it doesn't sandwich under the throttle body.

Once I replace the PCV valve and fuel filter and run the pressure test I will certainly know a ton more about where to backtrack. Luckily everyone here has given me some pretty great leads and I am learning

Jsweezy · 03-30-2017, 02:12 PM

Flux - something I just learned and I'm not sure this will apply to you or not, but, the 2010 and up 5.4ls do not have an in line fuel filter, I just ordered the manuals to see exactly where everything is but it's not on the frame like the older models.

Flux · 03-30-2017, 02:43 PM

Quote:

Originally Posted by Jsweezy

Flux - something I just learned and I'm not sure this will apply to you or not, but, the 2010 and up 5.4ls do not have an in line fuel filter, I just ordered the manuals to see exactly where everything is but it's not on the frame like the older models.

Oh boy. hopefully I can find it.

Thanks Sweezy

Steve_382 · 03-30-2017, 02:50 PM

I had to replace an ignition coil on mine, but at least the computer showed a fault. Then a second one went bad, so I said just replace them all. You could feel it missing a little on idle, and also felt weak at highways speeds.

Jsweezy · 03-30-2017, 06:59 PM

So I just tried resetting the learned parameters on my van to see if maybe it just went funky for whatever reason.

It's easy to do, just disconnect the negative battery cable from the battery and attach a jumper wire from the positive battery cable to the negative battery cable (that's not attached). Be advised this resets everything so your radio will be blasting when you get back in.

Started it up and my problem now went from an every now and then funny drop or roll of rpms from about 600-400-600 to a solid roll of rpms from 600-400-600.

Flux · 03-30-2017, 08:48 PM

Alright, let me say it:

F!

So I dropped in on the dealership to get parts and ordered a PCV valve and hose. Have to get em tomorrow. Asked the guy about the fuel filter and he couldn't find one. What he did find is that the sending unit and pump in the tank have a "Lifetime Fuel Filter" built in.....OK, sounds good.....I guess....until it clogs and your lifetime fuel filter turns into replacing the entire sending unit.

I then asked him to look up the Fuel Pressure Regulator and he couldn't find that part either. WTF??

So I picked up a fuel pressure gauge and headed home. Checked quick up front on the rails and couldn't see the fitting. Pulled the dog house and looked and............there's no place to test pressure on the rail!! I can see the fuel line come up and into the left rail...It says fuel on it! I see the hose spanning across to the other rail and NOTHING!! I'm dumb but that thing is simply not there.

F!!

So here's a list of things that I could troubleshoot that aren't there:

Fuel Filter
IAC Valve
Fuel Pressure Regulator
Fuel Pressure

The hard part here is there is really no place to find any info on the late model V10's that I have run into except here. So I plugged in my monitor and watched some live stuff like the Short Term Fuel Trim and saw that as soon as I let off the pedal after a quick rev it would drop to as low as -25% . I have no idea what that means or if it's good or bad, but it's about the only piece of info I could gather. I'm perturbed because I don't like the way the van runs with this dropping RPM thing and hopefully it can be fixed. I'm afraid my only recourse is head for the dealer.

One thought that I had was the Agile boys surmised is my van may have been tuned because of the way it shifted. John noticed it too. I am wondering since it seems like there is some fully electronic scheme going on here that maybe if a tune is in there it's messing with something. I have half a mind to take it to the dealer and reflash it and see. I plan on getting a 5 Star anyway so it would be good to know there is an actual stock tune available to save.

The other thing I can think of is that the turn over from stock tank to custom tank effected something. I can't think of what, but.......

I drove my 06 F250 Diesel and the Wife's 03 5.4 expedition today and neither of them have the RPM's drop out like that when you let off the pedal. Frustrating because I want the rig to be perfect and I also enjoy learning the ins and outs of the engine etc, but this thing might be a brick wall for me. Can't even figure out where to test the F-ing fuel pressure!! Even if I could I would have no idea if the pressure is right considering how different this engine seems to the 8-15 year old versions.

Jsweezy · 03-30-2017, 10:21 PM

My one piece of advice in all of this is to buy the manuals for your year van on eBay if you plan on working on your van yourself, which it seems like you do. It will literally spell out the steps for fixing things and it has all of the schematics so you won't be surprised that there isn't a fuel filter. I had one for the hot dog and as soon as I went to work on the new van and realized I didnt have it I ordered them for 50$+shipping on eBay.

I ended up fixing my issue and I can't tell you exactly what it was but I can tell you what I did to get to the sigh of relief.

Pulled Doghouse

Pulled Drivers side PCV Tube
Pulled Drivers side PCV Thing in valve cover
Cleaned PCV Thing and put it back in drivers side valve cover
Reattached the PCV Tube to the drivers side valve cover

Pulled Passenger side PCV Tube
Pulled Passenger side PCV Valve
Cleaned Passenger side PCV Valve with Intake cleaner and put it back
Reattached the passenger side PCV Tube

Disconnected the negative battery cable
Pulled the air intake all the way back to the Throttle Body
Disconnected throttle body connection
Cleaned throttle body (intake cleaner, toothbrush, shop rag) until it was stupid clean
reattached the hose up to the part where it attached to the air filter housing
reconnected the Throttle body wire connection
cleaned MAF
Reattached the air filter housing and installed it on the van (4 bolts, 8mm)
put the rest of the engine bay back together

connected the jumper cable from the positive connection to the UNCONNECTED negative connection for a couple minutes while I put tools away
took jumper cable off and reattached battery

turned ignition to on and waited for all of the lights to go out
start van(engine light will stay illuminated so I just waited until about a minute after it blinked)

let it run for 10-15 minutes while I continued to clean up and waited to hear it do something stupid but it never did.

Feel like a million bucks because I get to tell my wife I fixed the van and it didn't cost any more money!

Hope this helps you in some way. Sometimes its seriously the dumbest stuff that seems like a big issue, im sure you will figure it out.

edit - that last sentence meant to be more along the lines of, sometimes its the littlest things that are wrong that need fixing but we always assume its the biggest ones so they get overlooked.