Need some diagnostic direction

[Sonofbumperbolt]

We had a Navajo with the 3.73s and I agree its a great ratio for these rigs.
I am basing the 3.55 ratio choice on a couple of things:
1) this Ex came from the factory with 225/70/15 tires. The PO had 235/75/15LT tires put on. This obviously changed the net final drive ratio and helped attribute to moving the engine out of the power band. 3.55s will counter that effect with 235/75/15 tires, bringing performance back to stock configuration. It should also correct the speedo error.
2) We had a 92 4dr Ex with 3.55s and 235/75/15 tires and it was perfect for our use/driving style. It regularly delivered 21mpg on the highway with a slight loss in town.

Having said all that if I find a good deal on 3.73s I won't pass them up and simply change the speedo gear to correct. This is my daughters school car and I want it safe and behaving nicely above all else.

I appreciate all of the comments and advice on this matter.

 

[Sonofbumperbolt]

Side note: I had a caliper lock up last week so did a full brake job on the front end.
New:
Rotors
Pads
Rebuilt Calipers
Wheel Seals
Bearings were perfect so I re-packed
I did it all for right at $100 with online coupons from AAP.

 

[Sonofbumperbolt]

A while back we traveled to Minneapolis Minnesota for the Northern Lights volleyball tournament. 80 miles south of Minneapolis in a very heavy downpour the EX died. We hitched a ride with friends and got home safely. The next day I rented a U-haul trailer and went back up to get it. It was a 13.5 hour 750 mile trip and made for a long day. I got the EX home and charged the battery (it was dead from leaving the hazards on) and the EX started right up. We have been driving it ever since without incident, even going as far as St. Jo Missouri. Not sure what to think.

 

[larrydd999]

Not trying to hijack the thread, but I would verify that the charging system is working. You should not have had an engine die while running if it had started earlier without a jump. You can run without a battery (although I strongly suggest not doing so...).

 

[Sonofbumperbolt]

I checked the alternator output - 14.6 to 14.7 volts.
I checked the fuel pressure and here is something interesting: When I first bought the vehicle it would not hold pressure after the key was shut off as mentioned earlier in this thread. Now it does. I think the check valve may have been stuck or gummed up on the fuel return.

 

[Sonofbumperbolt]

Loaded up the family and took my daughter to compete in the Junior Volleyball Nationals in Minneapolis. We left Sat. and got home late Thurs. The Ex ran perfect with nary a bobble. We put on right at 1100 miles. Gas milage was as follows:
First fill up: Mix of local driving and interstate, 19.73 mpg
Second fill up: Interstate with a bit of Minneapolis driving, 20.20 mpg
Third fill up: Minneapolis driving, 17.00 mpg
Fourth fill up: Interstate with a bit of Minneapolis driving, 20.23 mpg
Overall trip average was 19.29 mpg. I'm pleased with it.

 

[gmbroy]

X3 The 3.73ls is the way to go & the upgrade to disc brakes in the back is great also . Nice ex