Edge 3.5 Rough Idle At Rest, No Codes, Numerous Tuneup Items Already

[EdgeAWD]

09 Edge, rough idle mainly at stop light with foot on brake.  Less in neutral.  Many tune up items done to this car, in list.  170k, regular oil changes, clean valve train (no sludge), has improved but still an issue.  Have not checked vacuum reading yet, what is a good tap for this motor?  May be missing something but this is most of it.  

 

-new motorcraft platinum fire wire plugs

-all new 02 sensors reading voltage. 

-new right valve cover gasket

-cleaned throttle body very well, re indexed with reset 

-cleaned maf new gasket, age

-new upper intake gaskets

-clean air filter

-no codes but registers dacs if a wire is diconnected

-very smooth on highway, no bogs or performance issues under load

-similar to another issue mentioned by someone where the idle seems fine at about 400 rpm above the lowest resting idle (they where thinking of even doing a custom aftermarket program ((may or may not be a good idea))

-evap purge valve seened closed, check by self, did not have full on vacuum pump to check it, cannot generate that much vacuum but seemed like no air got past, did not want to throw parts at it

-brake booster was replaced, did not see any vacuum hose issues with plumbing when looking at it, had various things apart

-pulled 4 injector wires when looking at it, drastically changes idle, cannot get to other 2

-stated running higher end fuel injector cleaner, proper ratio with 20 gallons of gas

[EdgeAWD]

new throttle body gasket, not maf

[EdgeAWD]

Posted previously for variety of tune up items.  Had trouble finding vacuum port, had to use the one of the throttle body, disconnect purge valve.  Hopefully that is adequate to get the a good reading.  I am seeking peoples' experience with the operating range.  The vacuum at idle, full operating temp is barely 16.5.  It seems to be around 16 in drive with foot on the brake.  The idle is quite bad.  The needle is Very steady at idle.  When reving the engine, short blips or more duration, the needle immediately returns to resting 16.5 or so.  That seems good as far as the engine is concerned.  Is this range pretty low?  The specs seemed to be 17-21 or 18-22. 

 

This has had a progressively rough idle over the last couple weeks.  The car is now bogging, almost stalling when driving into a parking space after driving in town.  It corrects itself so far, does not stall. 

 

Has anyone had their typical vacuum around 19-20 vs this reading?  Might it be a good idea for it to take up a temporary smoking habit, or smoke test.  Some people posted using cigars with various methods.  Think I would prefer the one with a fluid pump vs smoking the cigar.  I do not have a smoke machine. 

 

I posted a long list of tune up items previously.  I re ran the vac test; think it was a better connection on the tbr.  I plan to drive it for a while so the extensive tune up items seemed prudent.  One big item was the lower 02 sensor that was always stuck on .8 volts.  The current one, though not as active as the uppers, has a lot more dynamic voltage now.

 

Basic fuel trim readings are below .5 for short term and long terms are fairly equal.  When running the engine at about 3500 rpm, the readings are steady, do not go way up, looking for fuel.  I had some concern that the fuel pump may be involved as it has 170 on it.  This process may be useful to someone else who is dealing with a rouge idle. 

 

I believe the gas mileage is a bit worse right now also.   

[EdgeAWD]

Also, there is no detectable hissing noises. Have seen some people using carb cleaner, seems random.  There is not much room to do anything on the right side of the motor. 

[1004ron]

What are you using to read codes?

[EdgeAWD]

I have mainly been using a handheld scanner.  The other day, someone hooked up a snap on computer.  There was no stored history of misfires or apparently vvt error codes.  I did observe short term fuel trims, even held the rpms at 3000 when watching them.  The short term and long term ones never get above .5.  The short term ones decrease slightly when running at higher rpm.  

 

Yesterday, I did not have any stalling condition, mainly rough idle when the motor settles down to resting idle.  If there are no error codes of any kind is that absolute or could there be other ignition/fuel issues?  I am half way through the techron injector cleaner, cannot say right now if that has helped.

 

I replaced a new defective trans mount (anchor, dont buy one) a short while ago. I put a jack under that and the oil pan, put a bit of pressure on it, there is no difference in idle with that test.  The engine mount has 12k miles, it seems good.  

 

I did a primitive smoke test.  I put the only hose that would fit in the valve cover breather.  I used a rubber glove on the air intake.  It did inflate that a bit.  I am not clear how much pressure I need to make smoke blow out, if that test was valid.  I did not see any smoke escaping anywhere.  

 

I am still wondering if I am suppose to be at like 18 instead of 16.5?   I am at 900ft in elevation.  Again, the vacuum needle is dead steady, returns instantly to idle vac after reving it.   I do not know what the exact range of vac is suppose to be on this without spending hours looking through the manual.  It is 5000 pages.  The one I have is hard to search, pdf.  If the vac was low, would I need a really advanced vacuum leak test?

[1004ron]

The only scanning device I have full confidence in, is Forscan and Forscan Lite.

 

I cheap OBDII dongle and the free Forscan Lite is the most cost effective option.

[EdgeAWD]

did not see this.  I have the forscan interface with the switch.  I do not have a cheap laptop so I have been hesitant to use it.  when I plugged it in, there where no codes present a bit ago.  I am not familiar with extensive engine balance tests, charting with that app.  the fuel trim data was off an actron live data which seems pretty good for basic info.  getting into testing the ignition, idk.  

 

the snap on computer is a higher end one but the person was not interested in doing much to diagnose it like a drive test,  

 

I still do not know if 16.5 vacuum is low for 900ft with this motor?  I do not know what is typical.  the good news is the needle was very steady and returned quickly with revs.  

 

I do have an anchor engine mount with 12k miles.  those are not good.  however putting light pressure on the oil pan with a 2x4, it did not change the rough idle.  the trans mount already failed, replaced it.  

[EdgeAWD]

testing some simple things on this engine is a pain as the upper intake goes right over the right side.  I could even compression test the left side.  I would have to buy an adapter to test fuel pressure but it does not behave like the pump is failing on the hwy.  

[EdgeAWD]

am happy to provide feedback on other peoples suspension or PTU questions.  surprised one one has any feedback on a basic vacuum spec?  the engine seems like it is almost stalling when pulling into a parking lot off the road, the goes back to horrible idle at 685.  the idle is horrible doubt it is an engine mount.

seems like mileage is also bad.

 

has anyone had a bad torque converter issue? no pronounced noise i can detect, no shifting issues, rev bang, whirling.   for those worried about the 6f50, mine had really clean fluid, no debris, no noises, no shifting issues at 170.  maybe I got lucky but seems like a good trans so far.   

[1004ron]

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