Saturday, November 7, 2015

Boogity Boogity Boogity, Amen

This post is about a week late, but sometimes real life gets in the way of building ridiculous machines. I'm writing this post from my hotel room in Japan. Every year I have to come here twice to discuss the jobs I manage with my Japanese counterparts who requested the work. I'm not complaining since it's nice to have a change of pace, but sometimes it's a bit inconvenient. Enough "not complaining", let's talk about ridiculous machines. When last gave an update, I had just had the fuel injectors cleaned and they were ready to be installed. Well, that happened and I found a few small issues with the fuel system. There was a nylon hose that had a tendency to kink, so I remade it so that it wouldn ' t kink. Additionally a compression fitting was a little loose but once I tightened it, there were no issues.

I had to add two temperature sensors to the the cooling system (so now there are four sensors because more is always better). The stock cooling system has two sensors, one for the ECU and one for the instrument panel. I had to add a sensor that matches the Ranger temperature gauge, and a sensor that controls the electric cooling fans.

Removing the engine for the last time

Coolant Temp Sensor bungs

This swap also placed the shifter too close to the bench seat so I modified the shifter handle to allow a full range of motion. The shaft is moved forward to clear the seat. It looks a little goofy, but works just fine.

One of the final tasks before starting the engine was to drain the old transmission fluid and refill with fresh syncromesh fluid. When I pulled the drain plug, I was glad that I had decided to change the fluid rather than just top it off. The magnetic drain plug had developed a furry metallic hairdo, made of bits of gears and dog clutches. Not wanting those violently discarded bits to find their way into a bushing or bearing, I cleaned the drain plug and refilled the transmission.

The RB20's mass air flow meter has a unique flange which does not make mounting an air filter an easy task, so I had to make an adapter. Out came the cutoff wheel and welder, and I whipped up another ugly, but functional part. The flange warped from the heat of welding and I did not have a good way to flatten it, so I applied some foam tape to the circumference of the hole in the flange to seal it.

With all the pieces in place, I could finally try to fire it up. With the key on, the fuel pump would prime but the starter would not engage, so I just hotwired the truck to start it. It worked out pretty well. The engine fired almost immediately and sounded fantastic. 

Eventually I took the truck for a spin around the block and it is smooth as butter until you start to get into the boost. It sounds like Lucifer's vacuum cleaner at that point, which I think is normal for the RB20DET but it also begins to buck and surge which is not normal. I think the mass air flow meter is unhappy with it's location. In it's current configuration, the airflow path almost makes a U-turn right behind the meter, which is very different than the stock configuration This causes problems because at higher flow rates, the air ends up "dodging" the airflow meter's probe. The probe is in the center of the meter, and the meter expects that the flow through the center of the meter will increase proportionally to the total flow through the meter. When there is a bend immediately before or after an airflow meter, the flow through the center of the meter is no longer proportional to the total flow through the meter, and the ECU can no longer determine the correct amount of fuel to inject, causing the bucking and surging. Next time I work on the truck i will change the intake.

Bonus:. This was a side project that Jen and I had during the past few weeks While furniture shopping (so wierd, since when did I furniture shop ??) Jen pointed out a couple tables she liked, and when I saw the price tag I had my typical knee-jerk reaction of "PFFFFFT! We can do better than that!" Jen agreed so we spent a little time putting together a couple tables.

Bonus # 2:. A Nascar invocation-turned-song will be stuck in your head all day.


  1. For your coffee tables, did you Dad hook you up with those tops or were you able to find some prefab tops and made the bases to match?

    1. These were the ones we built in my dad's shop.