Misfire, where do i go from here. (Page 16/18)
Dukesterpro MAR 14, 11:47 AM

quote
Originally posted by ArthurPeale:

Wix filters are considered to be far better than Fram.

what is this "hernia" thing you're talking about ?







Best way I can demonstrate it. New filter after diesel soak did not exhibit the bulge

[This message has been edited by Dukesterpro (edited 03-14-2023).]

Patrick MAR 14, 05:39 PM

quote
Originally posted by Dukesterpro:

New filter after diesel soak did not exhibit the bulge



Can't see any connection between between a diesel soak and no "bulge"... unless you're suggesting that an oil gallery was plugged so badly with gunk that the resulting oil pressure was forcing the bulge in the seal?


quote
Originally posted by Dukesterpro:

a new Fram ultra filter (I was using AC Delco previously)



Don't know if you still have both a Fram and an AC Delco oil filter off the car to check... but do the oil seals on the two brands of filters line up perfectly with each other, or is there a slight difference?

[This message has been edited by Patrick (edited 03-14-2023).]

zkhennings MAR 14, 06:02 PM
You do lubricate your oil filter o-rings with fresh oil when installing correct? It seemed like oil filter o-ring was going to be the issue, just cuz a leak that big will be obvious where it is leaking from. And you kept indicating it was only visible around the filter.

Your 15 min oil change was probably dirty just due to the diesel loosening up a buncha gunk.

Any metal particulate in the oil or diesel?
Dukesterpro MAR 15, 08:36 AM
Patrick,

I am suggesting the oil gallery was plugged to high heaven. I cut open the original filter and found the filter media collapsed and cracked. Not to mention the filter was filled with sludge. Looks like the insides burst and let sludge past the filter and into the oil gallery. Plugged her up pretty good. Hence why the new filters O-Ring developed that bulge and let the oil run out. After the diesel soak, I am left with a duke that in the year I have owned has NEVER run so quiet, its like a completely different engine its not even funny. It doesn't even tick on startup anymore. 50 miles of running in so far and no more oil leak. Comparing my second ACDelco and First Fram the seals are identical. in outer diameter but the Fram seal is a little thinner both in height and width.


zkhennings,

Yes, I always give the O-Ring a generous rub of fresh oil when installing. I believe a clogged gallery was responsible for the blown O-Ring seals. The matter so far I believe to be resolved.

I did figure the oil was dirty due to the diesel flush, I was more trying emphasize just how dirty it was for only 15 minutes of running.

I drain my oil into a white tray 1 qt at a time. Zero metal particulates or shavings, just grimy and sludgy.
Now back to that misfire. I will keep you guys posted as information develops. Thanks again for all the help!
Dukesterpro MAR 21, 02:58 PM
Oil issues have been resolved.


I managed to fix my bouncing Tach. I found the tach filter way further back into the harness than I initially thought. For my 84, it was in the plastic shielding all the way back by the coolant fill neck. Low and behold, disconnected ground loop. After reconnecting the tach works perfect.

Im going to redo all of the ground on the motor to weed out that situation.


A more interesting discovery is that my TPS is not bad. The little tang that moves the TPS arm is actually holding the TPS at 1.2V and if I bend the tang to get it down to about .3 the engine continues to high idle and at full throttle the voltage is only about 3.8 so I'm guessing my throttle plate isn't fully closing.
Patrick MAR 21, 03:46 PM

quote
Originally posted by Dukesterpro:

The little tang that moves the TPS arm is actually holding the TPS at 1.2V and if I bend the tang to get it down to about .3 the engine continues to high idle and at full throttle the voltage is only about 3.8 so I'm guessing my throttle plate isn't fully closing.



Aw man... despite my best efforts, you still bent it.


quote
Originally posted by Patrick:

With the presumption that your throttle is closed as far as it should be... try adjusting your TPS. No, don't bend the tang. Watch/listen to the way the fella in this video does it. He rotates the TPS. If your TPS isn't slotted, break out the Dremel...

Throttle Position Sensor operation
Dukesterpro MAR 22, 12:27 PM
You see patrick, I dont listen so good.

I completely forgot about your post. Will straighten the tang back out and try your method.
Patrick MAR 22, 04:02 PM

quote
Originally posted by Dukesterpro:

Will straighten the tang back out and try your method.



Now that it's already bent I suggest you don't bend it back, as that will only further weaken (if not break) it. But if the TPS needs further adjustment, by all means rotate the TPS instead!
Dukesterpro MAR 31, 05:17 PM
As further bad luck is bestowed upon me.

I have blown a head gasket. This car is cursed. Its the only explanation. I will get back with all of your after I repair the gasket and verify the head isn't cracked.
82-T/A [At Work] MAR 31, 06:08 PM

quote
Originally posted by Dukesterpro:

As further bad luck is bestowed upon me.

I have blown a head gasket. This car is cursed. Its the only explanation. I will get back with all of your after I repair the gasket and verify the head isn't cracked.




It may be time for a Quad-4/TwinCam swap...