The SX/4 money pit

[rollguy]

Got the carb back on and cured the vacuum leak.  Pulled it out of the garage and cleaned it up.  Looks pretty good eh?





The tags have expired so I will renew them Monday and get this inspected this week.  Just have to change out the wiper switch.  It only works on high

Looks like an "Eagle of the month" contender to me!!!

[IowaEagle]

Which reminds I guess I need to "announce" July's and move on to August. 

[Smitty]

Took the trusty rusty J10 out for a 180 mile round trip this morning and picked up the 4.0.  There is one big pile of wiring with that thing!!!  Have to sort through what I have and see if the electronic are worth using.  May still just HEI and motorcraft the 4.0 long block.  Not sure just how good the engine is.  I have an old tranny I will bolt up so I can attach the starter and do a CR test to see how the rings seal up.  This is going to take a little while to sort everything out and figure out all the accessories like how to mount the AC and such.  If I stay with the EFI then I need to figure out the wiring before I start anything.  Just not sure I got everything that I need.  The TJ stuff is quite a bit different than the XJ stuff cause the computer sits in the engine bay.

Will be gone for a few days.  We have to head over to NH for my Niece's husbands funeral.  He was killed in a motorcycle accident on the way to work the other day.  Retired Navy guy, 4 kids with 2 starting college in a few weeks.  Some lady pulled out in front of him and he died on impact.  This is not going to be easy to get through.

[IowaEagle]

Sorry to hear about your niece's husband.   Please give her our sympathies.   

Have fun with the "new" Jeep and all of its goodies.

[jim]

Darn.  I can't think of anything appropriate to say.
God be with you and yours.

[Smitty]

Had a few minutes to look at the money pit.  Did a compression test to confirm what I already thought.  The manual says to take the reading on the 3rd crank.  I did that and also at 5 cranks.  The engine was warm so it should have max sealing

Cyl 1  3 cranks 90psi  5 cranks 110psi
Cyl 2  3 cranks 90psi  5 cranks 120psi
Cyl 3  3 cranks 95psi  5 cranks 118psi
Cyl 4  3 cranks 90psi  5 cranks 120psi
Cyl 5  3 cranks 90psi  5 cranks 120psi
Cyl 6  3 cranks 90psi  5 cranks 120psi

The manual says 120-150 is norm.  Guess that explains the blow by through the breather.  Now I need to do the same for the 4.0 I bought.  Have to rig that up on the stand to be able to crank it with the starter.  The never ending project!!

[IowaEagle]

At least they were pretty even indicating no other hidden problems.

[Smitty]

Put the 4.0 on the stand and got it wired up to crank.  Mixed results.

Cyl 1 3 cranks 90psi  5 cranks 105  with oil  105
Cyl 2 3 cranks 120psi  5 cranks 130 
Cyl 3 3 cranks 150psi  5 cranks 150 
Cyl 4 3 cranks 30psi  5 cranks 60 with oil 60 
Cyl 5 3 cranks 145psi  5 cranks 150 
Cyl 6 3 cranks 140psi  5 cranks 145 

Since it did not come up with oil in the cyl I am assuming bad valves on Cylinders 1 and 4.  What do you all think?  Might just pull the head and have the valves done and see what I get.  I pulled the valve cover and the rockers for those cylinders were moving comparable to the others so I don't think anything is stuck.  Under the valve cover is super clean.  No sludge anywhere so it appears the engine was taken care of from an oil change standpoint.  This one goes on the back burner for a month or two.

Also, there is very little play in the distributor when I rotate the balancer back and forth so the timing chain is tight.

[IowaEagle]

How many miles on the 4.0

[Smitty]

Near the century mark as far as I can tell.

[IowaEagle]

That is low mileage for that motor to have such bad compression on two cylinders.  I wonder if it sat a lot?

[Smitty]

The guy I got it from had it sitting in his garage for a year or more.

[IowaEagle]

I have seen engines that sat a while have valves that went south.

[bigdog56e]

  Any valves that were open while it was sitting, could be rusted and not sealing.
                                                                        Eddie

[Smitty]

You know, you may be on to something there.  The 2 weak cylinders are 1 and 4.  they follow each other in the firing order so if that is where the engine was when the key went off for the last time it could be deposits under those valves.

Think I will go ahead with having the head done.  The compression on the rest of the cylinders was pretty darn good so I may assume that all the rings are good and it is the head that has the issues.  Once I pull the head I will get a good look at the cylinder walls and the innards to see if it tells me anything.