Rebuilt engine starter behaving oddly
#32
Given it is a new valve train and I hand cranked and made sure the rockers were all moving I think I messed up the timing chain. I just spoke with Russ Pottenger who has done the machine work and sold me the parts (and has been awesome!) and he told me that I may have been looking at the wrong dot on the timing gear. There are dots for the key way and a separate dot to synch the cam. I am guessing I missed that aspect.
The following users liked this post:
Queenjo (02-20-2023)
#34
Seasoned Member
Join Date: May 2021
Location: Western Washington
Posts: 468
Received 90 Likes
on
77 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
My recollection is the cam gear has an alignment pin and the crank gear has a key. It would seem that the only way it could be off would be it is the wrong application.
#35
#37
So the timing gears look correct. The only thing I can come up with now is I screwed up the rockers. I installed Harland Sharp rollers (I mean, the engine is apart, why not?) and the instructions were just to torque them all to 21 ft/lbs. It didn’t do any kind of zero lash plus x turns or differentiate between open and closed valves so maybe that is the problem?
#39
Have a read of this thread:
https://www.jeepforum.com/threads/ti...1/post-8156699
https://www.jeepforum.com/threads/ti...1/post-8156699
I really appreciate all of you taking the time to offer your insights!
#40
Seasoned Member
Join Date: May 2021
Location: Western Washington
Posts: 468
Received 90 Likes
on
77 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
The stock rockers are not adjustable, and I believe those pretty orange roller rockers are also non-adjustable. I saw in the reviews of those things that you are required to remove the baffles from inside the valve cover. Nothing I could find says what happens if you don't.
#41
The stock rockers are not adjustable, and I believe those pretty orange roller rockers are also non-adjustable. I saw in the reviews of those things that you are required to remove the baffles from inside the valve cover. Nothing I could find says what happens if you don't.
I checked to see if they hit the valve cover before I closed things up. I think there are different baffles on different valve covers. I have aluminum one and it only has small baffles under the vents. They are not adjustable but it seems that the torque specs if the valve is not fully closed might over load the spring and not let the valve fully close. I don’t know.
#42
Seasoned Member
Join Date: May 2021
Location: Western Washington
Posts: 468
Received 90 Likes
on
77 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
This guy, starting at about 7 minutes 35 seconds in, starts talking about problems that can be encountered if you prefill the lifters with oil, which is something I've always done. He only briefly alludes to the lifters bleeding down after a time:
#43
The stock rockers are not adjustable, and I believe those pretty orange roller rockers are also non-adjustable. I saw in the reviews of those things that you are required to remove the baffles from inside the valve cover. Nothing I could find says what happens if you don't.
My worry is, if I remove the baffles, can’t oil get into the vents? Should I consider a spacer instead? All this assuming I verify that is the problem, of course.
#44
CF Veteran
Join Date: Aug 2020
Location: SoCal
Posts: 1,765
Received 470 Likes
on
384 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
Did you have the valve seats ground and/or valves resurfaced/replaced?
I would do a leak down test to determine if the air is escaping past the rings, valves or gasket.
I also recall reading something about removing the baffles but I recall that the VC wouldn't seat. I suppose if it just barely came short, you might just crank the VC bolts down. Perhaps just remove the VC and look for any marks
I would do a leak down test to determine if the air is escaping past the rings, valves or gasket.
I also recall reading something about removing the baffles but I recall that the VC wouldn't seat. I suppose if it just barely came short, you might just crank the VC bolts down. Perhaps just remove the VC and look for any marks
Last edited by Saudade; 02-21-2023 at 09:42 AM.
#45
Seasoned Member
Join Date: May 2021
Location: Western Washington
Posts: 468
Received 90 Likes
on
77 Posts
Year: 1988
Model: Cherokee (XJ)
Engine: 4.0L
Going through old threads on those rockers, some swear you can get by swapping out the baffle fasteners with flush heads - others swear you have to remove the baffles. Others yet say removing the baffles creates blow by problems and the spacer is the right way to go. You'll have to figure out which is best, it's not appropriate to give suggestions without being able to touch and see or have previous experience, which I don't. If you had head work done, I do think you should consider what Saudade has been trying to convey. Summit and JEGS (and others) sell adjustable pushrod length checkers. I personally would validate pushrod length prior to trying start up again. You could also do a compression check with the valve cover off and see what you get.