huntsman

okay so I done a compression test a while ago and cylinder 2 was low at like 80psi every now and then, a few months back did another compression text it was at 150. So recently since i still get the check engine randomly every now and then code p0302 pops up, i ran some seafoam to clean **** out. It was fine for a few days then I got the check engine light so I was like **** it ima do another compression test.

so here are my results.

dry wet - only did 2 to compare the difference
1-175 200
2-170
3-135 180
4-173
5-173
6-155

my jeeps a 98 year, now the compression seems to be fine in cylinder 2 I dont see how it misfires. Cylinder 3 is a little low as the difference between the others is pretty big which is weird I dont know why its at 135.

Anyway I previously put in new spark plugs, wires, distributor cap, rotor, injectors, I think i did pretty much everything chasing this misfire in cylinder 2. So I believe its low compression problem but i get the CEL randomly sometimes its fine for months and then il get it out of no where.

Iv read somewhere to soak it with pb blaster so thats what I did today and tomorrow ima fire her up and see how she runs. Then just gona wait and see if i get the check engine light. If I do then i might run some bg 44k through my tank and then do a leak down test as I wana get to the bottom of this!!

Any ideas what else to do ?

karl4x4

I would switch the wires for #2 and #5 spark plugs and see if the problem moves around. Or even go as far as switching spark plug from a different piston.
You could also try switching 2 injectors.

If nothing changes, at least it would confirm what is NOT wrong with it.

Radi

What do you mean cylinder 2 was at 80# "every now and then"? If you are getting inconsistent compression readings, esp. after adding a bit of oil to the cylinder you might have a valve problem.
I'd try the leakdown test and determine where you are losing compression- rings or valves. Vacuum gauge is also a good way to check valve operation.

Does the motor ever see the high side of 3200 RPM? If not, add some MMO to the oil, rev it up to 4K and hold it for a few minutes repeat a couple of times, allowing time to cool down in between. The valves don't rotate unless the revs get up above 3200, might have one sticking occasionally.

huntsman

When I tested it before which was a few months ago in cylinder 2 compression was low at 80psi then the next time I retested it was at 150psi. So its irregular I guess. Now yesterday I tested and it was at 170. Which is cool no check engine light yet.

Yes the motor sees above 3200rpms daily lol I drive it like I stole it especially on the highway ramps hehe.

I think like you said Ima do a leakdown test the next time CEL comes on or maybe il try running bg44k first and see if that **** helps at all. But think leakdown test is the way to go to confirm if something is wrong or not. Any good tuts on how to do it ? Im just wondering how I find top dead center?

belvedere

sticky valve?

huntsman

Possibly today when i started it ran fine and then a few min after wards it came up. But i guess i have a bad ground because i got that jeep gauge cluster problem where i gotta hit it from under the steering column to get my gauges to work. So i hit it and the airbag light went away n check engine came on lol. Now i dont think its low compression because after soaking it with pb blaster the engine is running smooth I can tell the difference it starts right up idles soft and smooth doesnt shake the vehicle its deff noticeable.

Also the throttle feels much more responsive and it just feels better. HOwever i pulled up the code and now i have 2 codes -__-

I got p1282 and p0302 misfire I think ima do a fuel pressure test and maybe some electrical test because i have no idea what else it can be for the misfire and il do a leakdown test as well.

Now p1282 says something about the fuel pump relay but on the code reader it said somthing about the accelerator pedal pos sensor low what does that mean ?