Mountain loop highway.

The Mountain loop highway between Granite Falls and Darington makes for a great Saturday day trip.  It’s close, scenic and offers the right amount of rustic appeal.  Plus there is little doubt that one has truly gone off the beaten path, as once the pavement ends somewhere around the ice caves you are treated to a well worn gravel road.  Well worn of course as when the hillside collapsed in Oso blocking the highway into Darrington, this not so well traveled route became important to those who call the area home.  

Now ow when I mean the pavement ends and one is on a gravel road, I mean a pothole filled gravel road.  Potholes as I discovered that quickly laughed at even 35 inch tires.  If you can’t find a clear path around the deeper ones, you had better slow down and drop each wheel in one at a time lest you find yourself turning wrenches on the side of the road.  

Now, this is a route that does not require a true offroad vehicle, though it helps.  You just might find yourself slowing down more frequently.    But don’t let that stop you.  The rustic charm is very much a part of its appeal.  The highway had been closed for some time after a bridge was washed out in a winter storm, but has been back in service since 2008 after the bridge was put back in service and the roadway restored.  

For me, it was a great outing and felt like it did some justice for what this Jeep was made for.  Though by the time I got back onto pavement close to Darrington, I noted my engine was revealing some unwanted noise from her lifters.  That will be another story, but for now try to enjoy the pictures.  

   

       

ProFlo Tuning

Fuel Modifier Table

  

1000

2000

3000

4000

5000

7000

WOT

0

0

0

0

0

0

6″

0

0

0

0

0

0

12″

+4

0

0

0

0

0

18″

+4

0

0

0

0

0

Spark Modifier Table

  

1000

1750

2500

3500

4500

6000

WOT

0

0

0

0

0

0

9″

0

0

0

0

0

0

18″

+6

0

0

0

0

0

Target Idle RPM

665

Idle Fuel Mod

+16

Idle Spark Mod

-3

Idle Spd Activity

0

Idle Control

On

Closed Loop Fuel

On

Base Timg

Off

Rev Limiter RPM

6000

Tps

14

Transient fuel

0

Cold start fuel

0

Global fuel Mod

0

Global sprk mod

-4

  

  

Observed Issues:

 
 

O2 sensor shows running rich at idle (expected)

Warm start idle will often surge slightly.

Otherwise runs fairly well.

I get some exhaust backfiring at idle, fairly soft.

 
 

 
 

Actions Taken:

Retarded timing to solve pinging

Added Idle Fuel to solve surging.

 
 

 
 

History:

Previously had terrible idle surge issues.

The vehicle had been dyno tuned, but the idle was not set with the foot on the brake, thus did not pick up the load of the hydroboost power steering pump and related braking effect.

The solution was when I finally added significant fuel around idle.

There was a little pinging on hills, solved by retarding the spark.