Post by CORE 4WD on Mar 8, 2006 22:53:16 GMT -5
I finally decided to fix that crack that appeared so many months ago. You know, the one that happens to EVERY 4.0 Jeep built through 1999! Pretty easy but is time consuming as a fair amount of stuff has to come off. Pre-soaking bolts with PB Blaster is highly recommended.
1. Disconnect negative battery lead (since we're working with electrical connectors)
2. Remove airbox and intake tube for better access
3. Disconnect vacuum lines, sensor connectors, and fuel line clamp. They're all different so you can't mess up re-installation.
4. Disconnect cables from throttle body (throttle, kick down cable, etc). They just snap off. Remove bracket holding these and zip tie out of way. You may be able to get away with not doing this, they're easy to take off so I did it to prevent possible kinking.
5. Loosen serpentine belt and remove power steering pump (don't disconnect lines) zip tie out of way.
6. Disconnect fuel line, I had to get a disconnect tool from Advance. It slides in around fitting and releases tabs, $5 or so.
7. Remove header collector bolts (exhaust pipe tie-in)
8. Remove bolts clamping down intake/exhaust manifolds. Intake will fold back over valve cover like so-
Take care not to bend, break or rip anything while doing this!
9. Clean gasket area using scraper (duh!) and vacuum to keep stuff from falling into head. Here's a couple shots inside the intake and head. I'm kinda suprised at all the carbon deposits, especially in intake as I figured just air flowing through wouldn't make all that c#@p in there! Lots of carbon on valve tops, too. Bet that mixture flow sux. I guess on a good note everything looked pretty uniform-
10. Pull off exhaust manifold, clean up and weld. Wish I had a TIG welder but this should do.-
11. I had to "match" Felpro gasket ports to old OEM gasket, holes were a little small and looked like they would block some flow. Used a curved Lexan scissors.
12. Re-install everything.
Seems to be a computer "learning curve" afterwards. Ran really rich after starting (I could see/smell the fuel vapor coming from exhaust and it was running rough. Also got a "check engine" light a few miles down the road, throttle surged some. I think TPS may have been acting up (since it was unhooked and hooked back up or possibly O2 sensor acting up due to no crack/different airflow!?). Checked for trouble codes, there were none and it's running good now (after driving to meeting and back), definitely smoother and not rich. I'll pull battery cable to see if light goes out.
Finished a couple hours before meeting, typical except for getting two hours of "slack" time before an event!
1. Disconnect negative battery lead (since we're working with electrical connectors)
2. Remove airbox and intake tube for better access
3. Disconnect vacuum lines, sensor connectors, and fuel line clamp. They're all different so you can't mess up re-installation.
4. Disconnect cables from throttle body (throttle, kick down cable, etc). They just snap off. Remove bracket holding these and zip tie out of way. You may be able to get away with not doing this, they're easy to take off so I did it to prevent possible kinking.
5. Loosen serpentine belt and remove power steering pump (don't disconnect lines) zip tie out of way.
6. Disconnect fuel line, I had to get a disconnect tool from Advance. It slides in around fitting and releases tabs, $5 or so.
7. Remove header collector bolts (exhaust pipe tie-in)
8. Remove bolts clamping down intake/exhaust manifolds. Intake will fold back over valve cover like so-
Take care not to bend, break or rip anything while doing this!
9. Clean gasket area using scraper (duh!) and vacuum to keep stuff from falling into head. Here's a couple shots inside the intake and head. I'm kinda suprised at all the carbon deposits, especially in intake as I figured just air flowing through wouldn't make all that c#@p in there! Lots of carbon on valve tops, too. Bet that mixture flow sux. I guess on a good note everything looked pretty uniform-
10. Pull off exhaust manifold, clean up and weld. Wish I had a TIG welder but this should do.-
11. I had to "match" Felpro gasket ports to old OEM gasket, holes were a little small and looked like they would block some flow. Used a curved Lexan scissors.
12. Re-install everything.
Seems to be a computer "learning curve" afterwards. Ran really rich after starting (I could see/smell the fuel vapor coming from exhaust and it was running rough. Also got a "check engine" light a few miles down the road, throttle surged some. I think TPS may have been acting up (since it was unhooked and hooked back up or possibly O2 sensor acting up due to no crack/different airflow!?). Checked for trouble codes, there were none and it's running good now (after driving to meeting and back), definitely smoother and not rich. I'll pull battery cable to see if light goes out.
Finished a couple hours before meeting, typical except for getting two hours of "slack" time before an event!
