Compression Test Results
Well, the stuff I found online said 2oz, and since a shotglass is about 1.5 oz, I figured one and a half shots would be just a tad over. And yeah, they all mentioned laying a towel over it then cranking it out. I was planning to do it, just didn't say it.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Have you ever checked for spark before? Do yo hear a hum from the tank/rear, (fuel pump running) for a second or two after turning on the Ign? (It does that, then runs cranking, then runs once the CPS tells the puter' it has started.
No, I have not. And I haven't listened for the fuel pump, either. I'll try and remember to do that next time.
I figured compression would be #1, so as not to waste time with any of that and just look into getting a new engine or head if I had gotten a cylinder with like 80psi or something.
Edit: Just walked outside and turned the key. Fuel pump is spooling up load and clear.
I figured compression would be #1, so as not to waste time with any of that and just look into getting a new engine or head if I had gotten a cylinder with like 80psi or something.
Edit: Just walked outside and turned the key. Fuel pump is spooling up load and clear.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
Cool. These inline 4.0's are nearly not mortal. Cast aside the old mileage thoughts. I've got one at 280K, and another that passed 200 last fall. Nether smoke or use much oil. Going past three, or even four K happens. Under 200K is a nu-bee. (unless your are 00 or 01)
So, I did a little bit of 'work' on the xj this sunday. If you could call it 'work', I would just call it poking around before football started.
I turned the engine over and laid out a towel... I didn't see anything really spray out. But the engine was turning pretty slow. I put the spark plugs in, tried to start it, and got a few slow turns and a few hesitant chugs. There was definitely a few puffs of smoke out of the exhaust, and then the starter slowed down even more and the battery died entirely. So I put the charger back on it and started poking around. I knew I had taken the ignition fuses out when I did the compression test, so I double checked those, and found IOD fuse blown. I replaced it, and then figured I'd check the under-dash fuses, and found a rats nest of wires where the PO had hooked up an aftermarket temp gauge and a little switch to turn the cooling fan on/off.
Since I am actually an electrical engineer (kind of, I design and lay out circuit boards), I ended up spending the rest of my time out there taking the dash apart so I could get to the wires and the ghetto fan switch. Meanwhile I was thinking about the the MMO, and realized that the battery was probably spinning to slow to spit it all out, but probably also too slow to cause damage when I put the plugs in (I hope?).
I pulled the battery, took it down to the Autozone and had them charge it. They told me it tested bad.
So my plan now is get a new battery (from Wal-mart, they are way cheaper and I like their return policy), pull the plugs, retry spraying out the MMO, then try starting it. This time I'll check for spark (I ordered this in line spark tester for $7). I also need to get a wiring diagram so I can fix up the wiring (and find out what's going on if the IOD fuse blows again).
I'd try jump starting it but my dead truck is in the way :/ I'm trying to sell it whole, but people either keep low-balling me, wanting 'just some parts', or just blowing me off entirely.
I turned the engine over and laid out a towel... I didn't see anything really spray out. But the engine was turning pretty slow. I put the spark plugs in, tried to start it, and got a few slow turns and a few hesitant chugs. There was definitely a few puffs of smoke out of the exhaust, and then the starter slowed down even more and the battery died entirely. So I put the charger back on it and started poking around. I knew I had taken the ignition fuses out when I did the compression test, so I double checked those, and found IOD fuse blown. I replaced it, and then figured I'd check the under-dash fuses, and found a rats nest of wires where the PO had hooked up an aftermarket temp gauge and a little switch to turn the cooling fan on/off.
Since I am actually an electrical engineer (kind of, I design and lay out circuit boards), I ended up spending the rest of my time out there taking the dash apart so I could get to the wires and the ghetto fan switch. Meanwhile I was thinking about the the MMO, and realized that the battery was probably spinning to slow to spit it all out, but probably also too slow to cause damage when I put the plugs in (I hope?).
I pulled the battery, took it down to the Autozone and had them charge it. They told me it tested bad.
So my plan now is get a new battery (from Wal-mart, they are way cheaper and I like their return policy), pull the plugs, retry spraying out the MMO, then try starting it. This time I'll check for spark (I ordered this in line spark tester for $7). I also need to get a wiring diagram so I can fix up the wiring (and find out what's going on if the IOD fuse blows again).
I'd try jump starting it but my dead truck is in the way :/ I'm trying to sell it whole, but people either keep low-balling me, wanting 'just some parts', or just blowing me off entirely.
I know!!
Thanks for the moral support. I am super excited about having a jeep, and seeing all the aftermarket stuff and looking through build threads has me pumped, I just have to get through the tedious part first.
Thanks for the moral support. I am super excited about having a jeep, and seeing all the aftermarket stuff and looking through build threads has me pumped, I just have to get through the tedious part first.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
You will want it cranking "briskly". Not sure how old you are, but these newer sometimes won't do phit unless they are. (I had a 67 Fiat I could push start in a parking space). Not happening here. You may. or may not find wiring help in here. (this is in my Sig. Btw)
(THANK YOU TOM!)> http://oljeep.com/gw/elec/cherokee/edge_cherokee.html
(THANK YOU TOM!)> http://oljeep.com/gw/elec/cherokee/edge_cherokee.html
Last edited by DFlintstone; Jan 23, 2017 at 07:37 PM.
Thanks, I'll have to do some reading on that tonight.
I'm 25 and before the Ranger (and now this jeep) I usually just stuck with Honda/Acura. I've been working on my own cars since I could drive but I've been lucky in the sense that any time I had a car that wouldn't start it was always something simple. And every time it was something serious, I would pay someone because it was usually my main mode of transportation and I needed done ASAP.
This is also my first real 'project'. I did a ton of little mods on the ranger, but again, nothing serious.
I'm 25 and before the Ranger (and now this jeep) I usually just stuck with Honda/Acura. I've been working on my own cars since I could drive but I've been lucky in the sense that any time I had a car that wouldn't start it was always something simple. And every time it was something serious, I would pay someone because it was usually my main mode of transportation and I needed done ASAP.
This is also my first real 'project'. I did a ton of little mods on the ranger, but again, nothing serious.
CF Veteran
Joined: Aug 2011
Posts: 10,489
Likes: 24
From: Nor-Cal Coast
Year: 90,84
Model: Cherokee
Engine: 4.0,2.5
MMMM....Late starter. At seven or eight, neighborhood kids brought their bikes to me to remove "training wheels", from there ride".
It's more fun to work with wood.
It's more fun to work with wood.


