cherokeefan_1
NAXJA Forum User
- Location
- North idaho
Do you have a smog station nearby? Run it through and get your numbers and we can compare if anyone else has theirs. I keep mine to keep an eye on any possible issues year after year.
Do you have a smog station nearby? Run it through and get your numbers and we can compare if anyone else has theirs. I keep mine to keep an eye on any possible issues year after year.
Do you happen to know what the cc volume of the combustion chamber of the replacement head? Its starting to sound like you are a half a point down in compression
No, I don't. This was the first engine I ever assembled. I *thought* I did a decent job with it, followed the FSM and other reading to the T. But, I guess I am/was at the mercy of the machine shop who did the work.
What exactly does "half a point down in compression" mean?
That is true. One thing I have totally spaced on is transmission issues. Ford had problems with the torque converter in the 90's that, when bad, could make it feel like you had a boat anchor when taking off from a stop. I'm just throwing stuff out there to maybe get more people to chime in with their experiences.
No real reason to run compression wet or dry, or leakdown. Vacuum reading was well within reason considering the elevation. He stated it runs very smooth, so no reason to suspect a weak cylinder.
With that new info, I'd be moving on to fuel pressure AND volume.
Vac @ idle is around 18-20.
Just because a cat was new doesn't mean it's good, especially after 14k miles if it's been overly rich. Get a shop to do back pressure on the cat but if it free revs quick it's probably not the issue. Some sensors are designed for high altitude, same with computer tuning, at least with various other vehicles.
Excellent pointI wouldn't rule out a back pressure issue. Whats the vac reading under load at ~2k to ~3k after a few seconds? Idle vac readings rarely show excessive back pressure. I have seen back pressure numbers in the 2-5 psi range that can make these 4.0's feel pretty slow.
Agreed. I have seen rich running vehicles destroy cats in hundreds of miles, not thousands. 14k IS pretty long if there was a slight issue.
Honestly, if everything else checks out I would do a back pressure reading. Most muffler shops can do it pretty cheap.
Just to add to this, every bent pipe I have seen from walker has been a kinked up mess.I wouldn't rule out a back pressure issue.
I can't log in there. I am interested in your cruise RPMs. It might be time to borrow a set of 33-inch tires.OK. I finally had time to hook my scanner (Torque Pro) up to it and give it a run. Torque has a website available for the runs, if anyone wants to take a look at it.
http://view.torque-bhp.com/ and login w/ my Device ID (351713082230320).
clydefrog said:Honestly, if everything else checks out I would do a back pressure reading. Most muffler shops can do it pretty cheap.