matt62485

finally found my issue. did a compression check today and found the cylinder 5 intake lifter was collapsing, ended up fatal failure after a couple pumps of the ignition and compression fell to 0.


however before it failed all 6 cylinders read ~92psi, no variances... all about dead even. all the other cylinders held steady at 92ish, and the lifters seemed fine (but i plan to replace them anyways)

would this be acceptable to try to ride out for a while, while i built a stroker on the side? i know 120-150 is desired, but debating if 92 could ride out for a while.

when it ran before and was misfiring, i guess the lifter would work occasionally and the xj felt like it had decent power, it was tolerable.

TheJerm

The biggest thing to look for in compression check is large variation between cylinders. 90 psi just means you probably have alot of miles/wear on the motor

mentalbreakdown00

90 is pretty low, but maybe could skate by for a while, don't you have to pull the head to get the lifters out? If you could stand it I would just ride it like it is until you can rebuild one or something

matt62485

thats what i was thinkin. has 190k on it. got it with a blown 0331 head, just swapped it out, cranked it up and been fighting the misfire since. shouldve replaced lifters while i had it out

figured since there was no variances in b/t cylinders it was probably fine to ride it out a while

yea, ima try to build a stroker on the side

mentalbreakdown00

Lol, last 0331 head I dealt with we replaced the head gasket, then had low oil pressure, checked main and rods all ok, had to pull engine back out and replace the cam bearings, then all was well, stupid 0331's

rrich

Of course you checked compression with a warm engine, pulled all the plugs out first, and blocked the throttle wide open. If not, it may explain the low readings.

On the stuck lifter - try dribbling Marvel oil or a "lifter free" solvent - even lacquer thinner down that pushrod. Keep dribbling it down every few minutes. It may clear the chunk of dirt out of it - MUCH EASIER THAN PULLING THE HEAD!
While you are dribbling it down push hard and release the pushrod several times - it may help to push the dirt out.
Sometimes it works, sometimes not. It's worth a try anyway.

matt62485

all but that ive been workin 72 hr weeks since january, today and tomorrow are literally the first 2 days off ive had in a week resulting in a 60hr work week since then, so my mind is fuzzy and u can tell where im going with this.

i didnt block the throttle open, didnt even think about it

ill try that lifter free, but it seems like its collapsed b/c its really "mushy"

rrich

The lifter is just a tiny piston pushed up by oil. Collapsed means it's stuck at the bottom, the pushrod would be very loose - so loose you could probably remove it without loosening it.
Your description indicates it's just gummy and not repositioning itself fast enough - "squishy..
If it's "squishy" it means dirt has gotten alongside the piston letting it leak - often it can be worked free with a little effort. Especially since you said it does it hot, cold it's fine. Oil is thinner hot.

All it takes is a tiny piece of grit you wouldn't notice in your eye.

Else you pull the head to get to it.

It depends on how much work you want to do - or pay someone upwards of 500.

matt62485

yea, i know what it is/how it works but it seems awfully gummed up, ill try to free it up with the solvent before i go pulling the head. if it wont, im doing it myself. im not paying anyone to do it for me when im plenty capable of doing it, its just a lot of work for something so simple. i put the new head on it alone, i, however, will not lift it off and reinstall it by myself again... i about killed my back

matt62485

bad news. got the head off and pulled the lifters. cam is toast, debating on a full rebuild or just slapping a new cam shaft and lifters and roll. if i do a full rebuild its gonna be a stroker.

this was like this when i got the jeep and had no idea since the head was cracked. i guess now i know whats really been contributing to my misfire issue this whole time
(bad lifter....)

this hole is not suppossed to be here



how far is wore down