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Yesterday evening I ran codes and performed the KOEO, KOEO switch test, KOEO injector buzz, KOER test, and only got a code for the VSS P0500. The VSS was under warranty, so I swapped in a new one and it helped with the occasional hard pedal. The trans now shifts nice and smooth like it used to.
The highway speed issue, however, is still there, but it's not as apparent, which suggests it's not a driveline issue, but an engine issue. The last time I filled up I dumped some Stanadyne performance formula in the tank and I'm thinking that it's what's waking/cleaning up the mystery injector.
I'm hoping I can do some data logging with the AE and monitor either cylinder or injector performance to get my answer.
To me it's just weird that it's breaking down over 60. Usually there are 50 to 1 more complaints for below 60 than above. How's your fuel pressure??
Found that odd too, not the first time I've seen it though...
A buddy with a 2007 F350 had a problem where at speed, the truck was a slug. You'd mash it and the truck would be slow to spool and have a hard pedal. It never shook the cab like mine though...
When it finally did die, the truck wouldn't restart because the injectors were just that bad.
As it turned out, injectors 1, 3, and 5 were bad and had to be replaced. Once they were replaced, they truck took off like a scared cat even running on the stock VXCF4 tune.
Fuel pressure crossed my mind too, the shop I'm going to may have a fuel pressure gauge they're willing to let me borrow. I'm also replacing the pump since it's almost 2 years old and may be questionable.
I thought you had a fuel pressure gauge, I guess not.
You could have a situation of a loose injector or leaking copper washer. When it's under load the combustion pressures are obviously higher and may be pushing past the copper seal and past the lower injector body oring into your fuel supply to that injector causing it to miss.
Just a theory to get your brain jogging.
Any carbon tracking on the mating surface of the washer? Is the lower oring in good shape?
Not that I noticed, it's one of the first things I checked.
I checked the injector bore itself too and it was spotless.
See the pics I posted...
Originally Posted by TooManyToys.
What sounds were you expecting to hear if they were?
A popping sound through the intake and exhaust. I actually bent a pushrod on my 7.3 trying to restart it after replacing an injector. I didn't get all the oil out of the cylinder and it bent a pushrod. The injector itself was questionable too, but a bent pushrod didn't help my situation. I eventually found the issue was my IDM and I had replaced the #1 injector 3 times for nothing, but I digress....
I'm driving down the freeway and at times the engine is reasonably smooth, other times it's either a mild miss or enough to shake everything in the front of the cab.
When I replaced the injector, it was smooth, but then another injector reared it's head and while it wasn't bad as it was, it was still there.
Originally Posted by 87crewdually
I thought you had a fuel pressure gauge, I guess not.
You could have a situation of a loose injector or leaking copper washer. When it's under load the combustion pressures are obviously higher and may be pushing past the copper seal and past the lower injector body oring into your fuel supply to that injector causing it to miss.
Just a theory to get your brain jogging.
The thought had crossed my mind the torque down the other injectors, but like an idiot I neglected to and have a feeling I may be paying for it.
It's common sense and a more awake and coherent me would've done it, but it was already midnight and I had to be up at 5:00am for work.
As for my time with the IDS yesterday evening...
Brad Paisley wrote a good song to describe yesterday evening: "Time Well Wasted". Couldn't get enough time with it and the test that should've told me what I needed to know, told me nothing.
-I turned off FICM compensation, turned each injector off one by one for 5-8 seconds a piece then turned them on again, nothing. They all behaved themselves.
-Performed a relative compression test and while I'm not 100% sure, I may have a hint as to which injector is the problem child. Every cylinder except #8 read 0% delta. (Cylinder #8 showed 1%) I know affected injector is on the driver side, which makes me suspect #8.
-Before I left for work this morning, I performed the bubble test by pulling the top side fuel filter and cranking the engine from the solenoid. Not a single bubble.
Some potential better news....
The mystery injector is starting to show itself with in town driving. So at this point unless someone has another test or idea as to how to find the offending injector, I'm just going to wait it out unless I can get my own IDS.
Have you messed with tunes as of late, correlate if you think back?
Did you return to stock setting and drive it then do a reflash?
IDS should show the injector right off with in a few minutes, try grabbing the engine harness while on IDS....
You opened a can of worms Razzi...
You may want to take a friend and the IDS out on the road and see what
it doing when you are having problems. Set it up so you can record the event
for later playback. (It's the movie camera icon.) Also setup some sensor
elements to record. Then you and the friend go for a ride and see if you can catch it.
<table border="1" cellspacing="0" cellpadding="3"><tbody><tr><td align="left" valign="top">Carry out a slow neutral engine RPM run up in Park or neutral gear.</td><td align="left" valign="top">For symptom occurring between 1,200 RPM and 2,300 RPM, GO to Section 4, Performance Diagnostic Procedures. CARRY OUT the Power Balance Test. For symptom occurring between 3,000 RPM and 4,000 RPM, GO to Section 4, Performance Diagnostic Procedures. Carry out the Low Idle Stability (ICP Pressure). If ICP sensor and connector are OK, CARRY OUT the Injection Pressure Regulator Test.</td></tr></tbody></table>
08-04-2015, 08:55 AM
