Sudden engine miss

[Bombadier]

i think i may have gotten some bad gas after putting a few gallons in tonight.....
engine started missing with an odd rumbling (almost like a dead cylinder?) and my oil pressure is next to nil.....
prior to this, my oil pressure would be around 40 driving and 15-20 at idle.....
my rear main seal and oil pan gaskets are leaking and as such my oil pressure drops as the oil leaks out....however, once i put oil back in, oil pressure goes back up to where it should.....
now it doesn't move period....
its dark out now so i can't really look much, but i need some help narrowing down things to look for....here's some basic info-
A. Rebuilt carburator almost 1 year ago, tuned up 6-7 months ago
B. Unknown mileage, but had compression test done recently with 120-5 on all eight cyl, also no blow-by into crankcase i.e. no air coming out oil filler, also does not burn ANY oil on startup or otherwise
C. new sparkplugs 6 months ago, distributor looks good, negligble wear on rotor, wires are fairly new as well, new ignition module less than 5 months old
.......
What worries me is the loss of oil pressure even after i added oil tonight as it was a little low....but all i can think of right now is either carbon fouling a plug or bad gas.....but again, why the constant low oil pressure??????
:confused: :( :confused:

[Jambo1]

Same exact thing was going on with my rig. The other night she just died at the intersection. Rare for her so I new something was up. Did a compression test(similar psi as you) put new standard champion plugs in ran, it a little richer, plugs told me I was running a bit lean, and she's ran great the next day. Until my exhaust gasket started leaking.

Oh, I found a plug wire seperated from the connector on #4.

It's a cheap way to start problem solving...new plugs.

Good luck

[Bombadier]

BTT

[Bombadier]

update-
had a chance to pull some plugs and found #5 cyl plug looked to be brand new! i.e. - i've been running on 7 cylinders and didn't even know it???? checked for good spark by holding plug wire connector next to block....yep, good spark, maybe a tad weak looking (coil's pretty old), but no reason why plug shouldn't be firing..... :confused:
<sigh>....i give up..... :(

[Allen78J20]

hehehe My j20 does the same thing, the wire on the far back plug under the heater core comes off sometimes and I think "man the jeep is running weird" then the light bulb comes on. You might be a vac leak somewhere.....