Tuesday, July 29, 2014

Back on the Trail


I stopped four wheeling about five years ago. Purely by coincidence, I assure you, my daughter just turned 5 years old... Well, after a brief stint as a robot, TC is back on the trail! Here's what I've been up to...

Tuesday, June 24, 2014

TC is a Robot!

TC is now a robot!

Every year Sparkfun Electronics hosts the Autonomous Vehicle Competition with robots that fly or drive themselves around courses.

The ground robots are usually 1:10 scale RC cars, sometimes larger like 1:5 scale we saw in 2012 or even a go cart that ran in 2013.

This year a few of us from my robotics club, SHARC, got together to enter the very first full size vehicle in the AVC. It was a dream team of some of the brightest tech people I've ever worked with.

I figured if you're going to enter a full size vehicle why not go all out so I volunteered my trail rig. The Jeep was a big hit with the crowd!

You can read more on my robotics blog to find out why we're not crazy or stupid, and see how the Jeep fared in this intense competition.

Read more here.

Wednesday, May 1, 2013

TBI Tuning: Spark

I've pretty well dialed in the VE (fuel) tables with average BLM numbers between 126 and 130 for most cells.

BLM is Block Learn Mode and basically indicates how much fuel the computer is adding or subtracting versus what's called for in the VE table. Low numbers suggest rich condition, high numbers suggest lean condition.

Earlier this week I worked on adjusting timing, starting with Bill USN-1's timing table on Binder Planet. After driving and minor tweaking, the part throttle timing appears to be pretty good, now.

Two issues remain. Sudden WOT from idle/stopped results in popping and stumble. I'm looking at a possible lean condition and/or timing issue.

Second, the vehicle has little power at 30mph (low rpm). Part of the problem is my transmission shift kit refusing to do part throttle downshift at this speed. Transmission linkage seems properly adjusted.

Using a '7747 ECM, $42 ASDU bin, there's the Main SA (Spark Advance) table, but it's modified by several things. There's a table for power enrichment spark advance which shouldn't be needed in my case and may be causing the first problem. There's also an accelerator enrichment (same function as a carburetor accelerator pump) which I've increased slightly to prevent lean out in hopes of preventing the first condition occurring anywhere else.

Finally, I've restored the Warm Bias setting. The Main SA table can be biased, that is, the zero point can be set to a positive number to allow negative SA numbers. The stock ASDU bin has this set to 9.84, in other words, that value is subtracted from any cell in the SA table to get the 'real' value. A value of 9.84 in the table is zero. A value of 19.84 is 10.00.

I had removed this bias and adjusted my timing table down by 9.84. Just in case this is causing problems elsewhere, I reversed this change, adding 9.84 to my SA table, and restoring the 9.84 warm bias value.

I haven't had a chance to test drive yet.

Due to personal reasons I need to take time off from the Jeep and the blog for several days.

Thursday, April 25, 2013

Grizzly Lake


One weekend in August, 2007 held several firsts for me and what is adventure if not experiencing new things? Adventure can also be found in places you've been, so long as you're steering your life outside of the daily grind into different territory. Both metaphorically and literally in this case.

Monday, April 22, 2013

TBI Test Drive and Super Chief

TC successfully completed the first cross-town test drive since rebuilding the throttle body. I wanted to go see Scott's newly painted Super Chief.

Scott's 86 GW, "Super Chief"
His truck is way prettier than my ugly, faded, dented, rustbucket.

I just did new injectors, new gaskets on the throttle body, and new gas tank. Before that, I had issues I couldn't seem to tune away. Lean spots where I couldn't bump the VE table up any further. I had to increase base pulse width (BPW) to an insane degree and still didn't quite get it solved.

Running the stock ADSU bin, it starts up easily--unlike before--and it drove pretty good but had some serious lean spots at high load, low rpm. I was able to tune those out and the drive back was improved.

More lean spots remain and it's running rich in the low load, low rpm areas. Hopefully I can tune those out, then get on with the highway tuning, and get it ready for emissions later this week.