CEL flashing, bad idle, severe misfire, P0302 P0316, compression test results

Discussion in 'SN95 4.6L Mustang Tech' started by evolucion311, Aug 18, 2011.

  1. Burns, I did drain the coolant before starting work. Some residual coolant remained and got into the oil when the head was pulled off.

    I drove a few miles to the parts store and pulled pending codes P0305 and P0316.

    I swapped cylinder 5 coil and am driving again to see if the code follows.
  2. 40 miles later no codes or pending codes. Misfire remains, particularly under load and in higher # gears (low gear ratios).

    The car will roar to life thru 1st and 2nd but shudders at 60mph in 5th gear. What gives? :fuss:
  3. Here's a video of the post valve job diagnostic scan with the engine running. Burns, what do you make of the fuel trim and fuel pressure data?

  4. Un-fugging believable.

    P0305 and P0316 after swapping the #5 COP to #7 cylinder. Code did not follow the coil. Unplugging the coil and the injector on #5 cause the idle to become poor. I can hear the injector tapping when listening with a screwdriver.

    I just put this damn thing back together and now I get the (so I assume) EXACT same problem on the other bank of the engine.

    What is different this time is that previously on cylinder #2 unplugging the coil and injector didn't result in ANY change of idle. Now unplugging #5 stuff does change the idle.

    I'm sick of this sheet.
  5. what happens when you try to drive easy thru all gears?

    mine was spitting and spuddering real bad with no code and coils were the problem,,when over 2000rpms i didnt feel anything wrong..just when trying to drive very easy

    i found a guy with 8 good coils to try before blowing cash...

    your code changed from 302-305 but not to 307...being it made a change tells me something is up with coils/connectors/boots..this was the only thing touched last to make a change?yes

    there is a link for china coils cheap 85 shipped to door,,,it might help on cost if money is tight..
  6. Just wondering what the results of the leak down test was on bank 2.
  7. Hot Cobra, I got p0305 immediately after car was put back together. I pulled #5 coil and swapped it to #7. Code did not follow the coil.

    Burns, I did a leakdown test (kinda) with the few minutes of time I had last night. If i had the motor set right for TDC #5 the crank shaft was about 305 degrees. Can someone verify this setting?

    Anyway, I heard air hissing through the oil fill cap. No noise thru dip stick. No noise thru intake or exhaust pipes.

    I'll do a proper compression test on it tonight and post the results. God hates me. What are the odds I blew a head gasket. Ugh.

    I should mention that I removed all water from the oil and no more has shown up. The water in the oil was from pulling the head off. Both oil and coolant are clean and I get no smoke at all.
  8. did you only have 1 head checked?

    have you pulled the engine harness off car and really check it out by un wrapping it?

    there is another large thread with a guy with a crown vic...he chased his problem around and around..his last find was a wiggle test on harness...

    your storys doing the same thing....however what was done last made a change,,,302-305..

    when i do engine work on my car i pull the engine harness and vaccum harness off the car and set aside...pinching wires /vacuum during work is hard to find when i problem happens afterwards because of it...

    just a thought..you touched engine harness to do work.didnt fix...you touched harness again to do more work,,no fix...than ripped into head...replaced parts and now trouble moved...

    leaves harness vs your work....you appear to be doing ok...

    a problem in pcm should keep spitting the same code...problem in harness should change with touching almost nothing,,,

    this has been a wild thread...

    the harness has alot of splices where a point on the sodder can poke into another wire causing crazy issuses.
  9. Hot cobra, thank you for your input and ideas, I'll check the wiring harness tonight when I run another compression test.

    The p0302 was defibuely being caused by the bad exhaust valve seat on cylinder 2.
  10. So check this out.... I ran a compression test on the engine as shown in the videos below

    The needle jumped up in "steps" up to, well.... just watch the videos here and give me your take. Is my compression tester on the fritz?

    The first time I ran un-oiled compression tests on this engine the needle jumped STRAIGHT to 105-125 on all of the cylinders, there was no stepping up action. NOTE: I goofed on my first compression test (original post) and ran it with the throttle plate CLOSED. These tests were done with the throttle plate wide open.





    WATCH ME - CYLINDER 5 (the one in question with the new misfire codes)



  11. I see nothing alarming on any of those cylinders.
  12. Which is weird.... my first compression test I did the compression was 105-115 on all cylinders and the needle shot straight to the value it indicated and didn't "step up" like this time.

    Now, the compression is stepping itself up and reaching much higher values than I got previously.... which leads me to believe that one of the testers I was using was bad.

    They were both rented from AutoZone and came from different stores. :shrug:

    In any case, the results are fairly uniform. Whether the true compression is 105 or 185 isn't really at issue for me.... what I'm more attentive to is that they are more or less the same.

    I'm ready to sell this car for scrap and turn it into razor blades. I've never been so puzzled before.

    I have no doubt that the stealership would have milked me dry if I had taken it to them.
  13. Hi, I have been keeping up on this thread since it started. I truley do feel for you as I have had a **** of a issue as well that the answer to was in my face the entire time. One month later nearly and a few hundred lighter I am close (hopefully) to getting solved and I am not the type to throw parts at a car without being certain that I have the evidence to correct to affected part.

    Without going back through and reading, and I know you have gone through this with out question is the injectors. When you pulled the intake did you pull the injectors one by one or did you leave them on the intake when removed? I just figured if you removed the injectors and did not mark which one came from which cyl then maybe one got mixed over to the other bank moving your problem from one side to the other? Just a thought.

    Mr. Burns knows his **** for sure and has inspired me to read for countless hours on the net to figure out how live data can point me in the right direction. I would be interested in knowing what your fuel trims and such look like at idle and higher RPMS when driving.

    Any chance timming on the affected bank could be incorrect since the engine was reassembeled?

    I know my 02 might not be much BUT there has to be a good resoloution to this.

    EDIT: The advice about the harness is good. I would remove the big main harness plug on the passenger side and OHM every single wire out. I would also OHM out the main harness plug to the PCM. By the bat is the front 02's harness plug, OHM that out too to rule out any issues. :END OF EDIT
  14. StangMan, thanks for the input. To reply to your points:

    The fuel injectors were removed and returned to their original locations. I have swapped them to see if a code would follow, it did not.

    The timing components were put back together exactly how they came out.

    Please take a look at the video at the end of page 5. The fuel trim data is available with the engine idling and with a bit of revving.
  15. Evo- watched your video. Fuel pressure is that high b/c your IAT and coolant temps are causing it. Computer will ramp fuel pressure sky high when IAT >100* AND coolant temp is >200* to keep fuel from boiling in the rails, so that's normal. Keep up the good work. This has been a very informative thread! Good luck.
  16. Bullitt, may I ask how you know that? I'm not being snarky... I'm asking what your mechanical expertise is :)

    Please school me on the IAT and coolant temps and how the computer adjusts fuel pressure accordingly.

    Could this high fuel pressure (actual or imaginary) be causing my issue?

    Burns seems really surprised at it and my fuel trim data.

    I guess what I'm asking is: "Does my fuel trim data look normal or jacked up after the head repair?"
  17. STFT looked odd in the vid I watched until the end. I don't have sound on this work PC so I could not hear revs. But in the end of the vid, they looked a bit better. My car is a return style system. I think yours is a returnless but your FP got past 50psi on the scanner which does seem high. You have replaced the electronic FP regulator I think, right? When you had the rails off did you blow them out with shop air just to make sure there was no obstructions?
  18. I have not replaced any fuel related components with the exception of the fuel filter.

    I did not blow the fuel rail out with shop air.

    This thread is going to go down in StangNet history as one of the longer running unsolved mysteries.

    If only we could recruit a creepy sounding actor to do the voiceover for the television version :rolleyes:
  19. Evo- just an old retired electrical engineer with too much time on his hands. Been wrenching on anything that moves since I was old enough to hold a wrench. Worked my way through school thanks to a couple of different Ford dealership service departments. These days spend way to much time in the garage restoring old mustangs according to my better half.

    I don't think the fuel pressure issue is your problem. Just saying that with those temps you're gonna see it due to Ford's programming. It's normal for the circumstances.

    You're right. This is some mystery. I'm staying tuned for the duration.

    FWIW, I thought you had it nailed with the exhaust valve. I'm leaning toward an ignition/electrical gremlin now... keep on plugging. You'll figure it out.
  20. fwiw i did some datalogging some time back and my f/p slowly got up to 60 psi at idle, indicated pressure at the rail was ~42, at the same time i got a pending code for p0174. with that said, the car often bucks and hesitates and is low on power in the lower rpm range, not to mention it gets about 11mpg. at this point i doubt the f/p is the cause of my issues and i've checked everything i possibly could aside from compression. just throwing this out there since we have a few similar issues