Motor rebuild gave me 2 curve balls…….

[Kevin]

Hey all, thanks in advance for any help you can give
2002 Jeep Wrangler/TJ 4.0L 5 Speed CA emissions (may be important)

I had the ‘common’ Jeep tick and it drove me nuts so I got another motor to rebuild and get rid of the issue.
The motor was a previous rebuild with a MOPAR reman tag on it but it was far from being in good shape. Pistons cracked, water damage in #3, bent valves etc
Bored over .030″ new exhaust valves. valve springs, cam, lifters full rebuild
First firing of the motor gave me lots of clanking from the valve train, but I’ve always herd to break in the cam so I ran it at 2500 for 10 min. While it ran I looked for leaks and noises. I noticed after 5 min that the inlet tubes to the pre-cats were glowing red, not the pre-cats themselves, just the inlets. After 10 min i shut it down for the day
The next day after some reading I checked and found the pushrods were too long after the machine work (2nd rebuild on the motor) and that #3 intake lifter had collapsed
Pulled the head and replaced the lifter, placed shims under the rockers (.090″) Started it up and all was quiet, ran it at 2500RPM for 10 min. After about 4 min the inlets for the pre-cats started to glow again.
MAP IDLE 1.6 2500RPM .9
VAC IDLE 17.7 2500RPM 22.1
F BANK INJ IDLE 4.6 2500RPM 3.8
R BANK INJ IDLE 4.5 2500RPM 3.8
F UPSTREAM IDLE .1~.8 2500RPM .1~.8
R UPSTREAM IDLE .1~.8 2500RPM .1~.8
F DOWNSTREAM IDLE .68~.72 2500RPM .3~.6
R DOWNSTREAM IDLE .68~.72 2500RPM .3~.6
F ST ADAP% IDLE .4~2.3 2500RPM -1.2~1.8
R ST ADAP% IDLE -.2~1 2500RPM -1.6~1.2
F LT ADAP IDLE 8.2 2500RPM 7
R LT ADAP IDLE 9.4 2500RPM 8.6
Engine temp 199
Compression 170 170 160 160 165 170

I have,
Replaced the O2 sensors new
Swapped out the MAPsensor used
Swapped out the Y-pipe with one that had the cats punched out (Manifold with pre-cats back to the 3rd cat n muffler)
Unbolted the Y pipe at the rear to release back pressure
Smoked the intake – few small leaks – fixed
Smoked the exhaust – only leak is the weep hole in the muffler
checked the Cam Synchronizer
Cleaned the injectors
Injector OHMS 12.5 on all of them
Fuel pressure 45 steady

After all the little changes and tweaks I still have the glow at the pre-cat inlets and now the manifold glows also

Currently, have the valve cover off and rechecking pushrod length. Most of the lifters aren’t bleeding down, as I torque the rocker bolt the valve spring compresses, after 2 days of sitting under the spring tension the lifters still haven’t bled down. other lifters are soft when compressing, not sure if too soft or just feels that way cause the others are solid.

No check engine light (except, after I put on the punched out cats)
Runs good, no misses, no overheating, fires right up, stops dead when I shut it down, can run right up to 4.5K in 3rd gear and it has power

So, I have an exhaust heat issue and a lifter issue, not sure if they are related

Thanks again for any help or insight

Topic

[Richard Kirshy]

Have you considered you may have clogged or partially clogged cats?

[Kevin]

As I said, I replaced the Y pipe with one that had the converters punched out, and left the rear of it unbolted, no change.

[Jonathan Smith]

Back in the days before computer controls, glowing exhaust was an indicator of severely retarded ignition timing.

[Kevin]

Those were the easy days =)
Im leaning tward the injectors atm, have a set off the motor before I rebuilt it

Forgot to mention that I dont know if this was an issue before I installed the rebuilt one, the old one passed CA smog 1 week before I pulled it

[Author]

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