I'd vote for spark timing since it is the most likely, and the easiest to check and correct. There are about 19,250 threads here about getting this wrong and how to correct it.
I'd vote for spark timing since it is the most likely, and the easiest to check and correct. There are about 19,250 threads here about getting this wrong and how to correct it.
Appreciate the quick response. I can check that. That would be set by the cam pos sensor right? I’ve read over an over- on all 19,250 post about how you can’t index on the distributor-less setup. Can you give some clarity.
It can most definitely be installed wrong though. The alignment involves putting the engine on TDC, put the cam sensor in, make sure the holes line up. The procedure is in the fsm
Xjjeeps.com has the FSM available for free (.pdf download)
Correct. This is the exact procedure I followed during the rebuild. I will check it again. that would be an easy and free fix. ill let you know what I find tomorrow.
If that checks out, pull the valve cover and check the rockers with the #1 cylinder at TDC. They should be loose (valves closed)
This test would show that the cam was or was not installed a tooth off on the timing relative to the crank which would most certainly screw up idle and high rpm.
Checking similar on each or the other rockers at their TDC would help determine if they were all too tight and allowing compression to leak away, but IIRC you said you checked compression so this test shouldn't be needed in your case. Just putting it out there for the future that getting valve lash/pre-load off is a common problem on fresh rebuilds.
Good afternoon. Sorry for the delayed response. Weekends are jeep days. Check the cam pos sensor. Looks good to me. Hard to get my hand in to the spark plug hole to check to see if I’m on compression stroke but I believe I am.. if I was 180 out I don’t think it would run at all right? Someone gifted me an msd coil pack so that will go on later today.
check my coil pack reading in ohms and got a range from 1.0 - 1.7. This is high right?
Good afternoon. Sorry for the delayed response. Weekends are jeep days. Check the cam pos sensor. Looks good to me. Hard to get my hand in to the spark plug hole to check to see if I’m on compression stroke but I believe I am.. if I was 180 out I don’t think it would run at all right? Someone gifted me an msd coil pack so that will go on later today.
check my coil pack reading in ohms and got a range from 1.0 - 1.7. This is high right?
correction. My old coil pack was reading .9 ohms which is the same as the new msd pack. So that shouldn’t be the issue.
Okay, i feel like its time to throw in the towel. On Monday i plan to take it to the dealership and have them run diagnostics.
Today i installed the MSD coil pack. No chance. I then pulled out my cam shaft sensor. Rotated crankshaft via harmonic balancer with ratchet. Turned a few times an made sure i was on compression stroke. (I believe I originally was 180 out on that sensor. Put it back in with the toothpick method. I even reset the computer. Still crank but no start unless i held the gas pedal.
Dealership wants 150 for diagnostics and will then put that 150 towards the labor when they figure it out. I figure its money well spent if it gets it running. The Jeep has been down since October. Ready to get it back on the road.
Any last thoughts before i bite the stealership bullet?
Might want to go that route if you still haven't checked that the rockers are loose on #1 cyl at TDC on the compression stroke. If the timing chain is a tooth off, it'll run like *** and the cam sensor will be reading incorrectly too, which makes it run more like ***.
Might want to go that route if you still haven't checked that the rockers are loose on #1 cyl at TDC on the compression stroke. If the timing chain is a tooth off, it'll run like *** and the cam sensor will be reading incorrectly too, which makes it run more like ***.
gotcha, I’ll give that a try soon. The only reason I haven’t checked it is because I have solid compression which makes me think the valve timing is correct- I also triple checked it before it went back on. But I wouldn’t be surprised
Gotta eliminate stuff man. It's hard to diagnose over the internet, so eliminating the most suspicious things is always the first step. I say this because the engine got rebuilt, so base engine is suspect until proven otherwise.
Also. Do you have an ELM327 Bluetooth adapter? They're pretty cheap (like $10-15) and the app is free. Use the app "car scanner". You can datalog stuff to see what's happening. O2 volts, map, TPS, etc. It really helps with diagnostics.
Gotta eliminate stuff man. It's hard to diagnose over the internet, so eliminating the most suspicious things is always the first step. I say this because the engine got rebuilt, so base engine is suspect until proven otherwise.
Also. Do you have an ELM327 Bluetooth adapter? They're pretty cheap (like $10-15) and the app is free. Use the app "car scanner". You can datalog stuff to see what's happening. O2 volts, map, TPS, etc. It really helps with diagnostics.
How's your fuel pressure?
i haven’t yet check fuel pressure. Will hopefully do tonight.
also. I have a picture of my two timing marks on both sprockets lined up. For some reason it won’t let me post. Look to be lined up perfect.
