Terminal Velocity Install for EFI Systems

21 terminal velocity installed
Terminal Velocity Fuel Management System From Terry Components

Last summer I wanted to re-tune by 2003 King. It has a Screaming Eagle EFI system in place and I hunted down a tech who recently attended the most advanced EFI Harley-Davidson training. He was located at Bartels in Marina Del Rey, California.

Here’s the deal. If you check back through the King Reports you’ll see that we performed a mild hop up that contained Screamin’ Eagle mid range performance cams, a stage one kit to the air cleaner, Screamin’ Eagle heads and 2-into-1 Screamin’ Eagle Exhaust system. We also replaced the stock EFI system with a tuneable Screamin’ Eagle job. Unfortunately the tuning was restricted to specific Screamin’ Eagle platforms, like the Stage 1 kit or the 95-inch up grade. There was no specific tuning map for my configuration—figures. I can’t do anything normal.

The bike ran fine, but I always wanted that final tuning check. When I contacted Alan at Bartels, he told me, “Bandit, you need a code or I can’t tune your bike.”

A code? What the hell. Another password that needs to be memorized in life. A code that’s not accessed more than once a year? I didn’t even know where to look. I dropped any notion of dialing in the King and just kept riding her. But there was that nagging feeling that final adjustments were never made. I kept digging, then ran into Keith Terry, of Terry Components, at the Cincy show.

Keith told me about his new product, the Terminal Velocity Fuel Management System. Sounded ominious, but I kept listening. His system is not adjustable. It doesn’t need a dyno or a trained technician to dial it in. It does require an exhaust sensor to make it a closed loop system. Basically it analyses your system, checks the exhaust output and changes your timing for the most efficient fuel delivery at ever throttle position. Once installed it takes up to 50 miles for the system to analyse timing and fuel delivery and adjust. Then she’s golden, hopefully. We installed the system. Let’s see how we did.

12 battery post

First we removed the seat and disconnected the battery to prevent damage to the electrical system during assembly. I slipped a chunk of bicycle inner tube over the positive terminal to prevent connection during the operation.

13 electronic stuff
Wrong side, dipshit.

14 connection closeup
Wrong connector, put this cover back on and go to the other side of the bike.

Then we removed the left saddlebag and discovered that we had a set of cool Carlini bag rails that eliminate the rear crash bars. It was the perfect time to install them. We removed the left electronic cover and tried to figure the wiring. We were way off base. The DELPHI EFI module was under the right cover behind the carb. Everything needed to be messed with was on the right, not the left.

17 plastic conn

Here’s the connector splayed open, after disconnecting it from the bottom of the EFI unit under the plastic panel on the right side of the bike. The plug pulls down and out after you release the plastic sprung clip that hold it in place. Three small clips around the peremiter of the connector must be released after the tie-wrap was clipped off. Then the connector spreads open to reveal all the wiring connections.

18 inside plastic conn

While I stared at this mismash of terrifying wires Black Market John removed the air cleaner—simple right? This air filter has haunted us. First the bung in the center was spot welded in place and it popped loose. That meant the big stainless Allen spun free and we couldn’t reach the back. Somehow I spun it off and spot welded the bung again. It’s still holding.

15 removing aircleaner cover
The notorious Allen that holds the air cleaner cover in place.

We also removed the venting spacers to the throttle body bracket, but had to remove three Allens holding the air filter in place. The filter spacers come with factory Loctite smeared on their threads and the small ¼-20, 1/2 –inch domed Allens stripped.

16 removing aircleaner
These were smeared with liquid tephlon tape to make sure they sealed. We cleaned each fastener and washer off.

4 Allen welded

Then I dug out the Miller MIG welder and tacked old used, spare Allens to the fasteners and off they came. Then we grabbed a 1/2-inch box end wrench and removed the three filter stands and the backing plate slipped out of the way. We needed to reach the throttle sensor connector off the throttle body.

6 plug
Here’s the throttle position sensor connector from the ECU.

While I pondered the wiring. John loosened the two front tank bolts and unbolted the rear tank mount. We lifted the tank and slipped a chunk of 2-by-4 under the tab to allow us room to feed the Terminal Velocity wires under the tank to the throttle body.

7 removing under seat

16 block under tab

”Wait,” Keith Terry said, from Terry Components, “I need to point out that on Softail models the ECU is located under the seat. On Road King and FLH models it’s installed behind the right side, pull-off plastic panel.” Remember how we fucked up in the beginning. That’s what he was pointing out.

1 shrink tubing

Now that we had all the areas cleared for the operation we separated the wires and ran the three throttle sensor wires (blue, green and blue with white stripe) through shrink tubing under the frame rail and alongside other wiring looms up, under the tank. Keith supplied shielded loom, but we used shrink tubing. John was careful to position the wire-filled tube to miss leaning on any hot engine components before it reached the sensor plug.

custom chrome banner

8 terminal velocity ii
We positioned the unit a couple of times to give us more wire reach to the throttle body.

9 plug and wires
Here is the connector and the TPS wires.

We discovered that with the Terminal Velocity ECU unit strapped to the front of the DELPHI job, the wires were just long enough to reach the connector on the throttle body. The connector we needed was at the top and back of the throttle base on the left of the body.

We were told that we could remove the pins in the ECM (Electronic Control Module) plug so we could splice the wires and run shrink tubing over the connector. To be honest with you I didn’t want to mess with pins slipping out of that monster, then trying retrace their locations.

I traced each wire, carefully stripped ¼-inch insulation, where it could be conveniently soldered without damage to other wires. We cut the Terminal Velocity wire to a reasonable length, stripped it about 3/8-of-an-inch, wrapped it around the ECM plug wire and soldered it. Then we coated each connection with liquid electrical tape and let it dry.

First we located the appropriate wires at the back of the plug and their colors:

Number 10 was the ground wire and black.
Number 13 was the ignition wire and white with black stripe.
Number 30 was the crank sensor wire and was red.
Number 23 was the rear 02 sensor wire and was pink and green (for Dyna Glides).

”Wait,” Keith interrupted again. “Don’t forget that Dynas with factory 02-senosrs will supply input signals to the terminal velocity unit.”

2 wires
This shows the wires from the TV that were connected to the ECM.

Once the correct pin-numbers and associated wire colors were located we spliced in and soldered the Terminal Velocity black wire to the ECM black wire (ground). Then we spliced in the TV red wire to the ECM number 13 wire (white with black stripe) for ignition. Then we spliced in and soldered the wire at pin 30 (red) with the TV white wire for the crank sensor.

With the three wires soldered and sealed with liquid electrical tape we let ‘em dry. Carefully we made sure the wires were out of harms way as we closed the connector and replaced the tie-wrap. It was time to plug the connector back into the factory ECM.

10 dual aligator clip tool
Using the famous Frank Kaisler wire holding tool to hold two wires spliced during soldering.

Next we moved onto the throttle position sensor wires. It was good that we removed the air cleaner stuff back to the backing plate for better access. Keith called for cutting and splicing the wire a couple of inches back from the connector. I’m glad, because the wires barely reached.

11 liquid electr on wires

We soldered the blue/white wire from the TV to the gray/purple wire at the TPS sensor connector a few inches away from the connector. We stripped back the stock loom for access. Then we located the red/white wire at the TPS sensor connector and cut it back 2-3 inches from the connector. We soldered the green wire from the TV unit to the red/white wire from the sensor connector. Then we soldered the blue TV wire to the red/white wire returning to the ECM.

17 y-tubing with nut
This is a M18 by 1.5 metric threaded nut. Some systems require that you drill out the existing bung threads with a 21/32-inch drill bit. Don’t forget to use taping fluid to avoid rough threads and help with the threading process.

While this was happening we took off the Screamin’ Eagle pipes and hauled them to LA Chop Rods where they welded the 02 Sensor to the back of the pipe junction just before the muffler. Then they drilled a ½ inch hole into the center of the nut to allow the O2 sensor to reach inside the pipe.

We ran into a glitch at this point, ‘cause we were sorta sure the Screamin’ Eagle pipes were stainless steel. Keith sent a nut with the Terminal Velocity for the O2 Sensor, but it was mild steel. We discussed the problem with a couple of welders. Larry Settle said he could do the job with stainless rod. Gard tested the pipes with a magnet and it stuck indicating they weren’t stainless. He TIG welded the nut in place and we were good to go.

18 fitting on y-tubing

”Wait,” Keith said, “Don’t forget to twist the wires to the O2 sensors back, counter-clockwise, four turns before screwing the sensor into the exhaust bung.” We got it, installed the pipes with new exhaust manifold gaskets, screwed the sensor into the collector and were getting close.

21 terminal velocity installed

”Hold on,” Keith said, “Not so fast. Install two tie-straps to the Terminal Velocity module with the harness pointing down to a 6:00 position. Don’t over-tighten the sensor, but just allow the crush washer to seal.” Black Market John took care of it.

We were finished with the Terminal Velocity installation. We cleaned the air filter, sprayed it with cloth filter spray, found some new ¼-20 fasteners, avoided using Loctite and installed the air cleaner.

Next, we needed to connect the red battery cable connection to the positive side of the battery, turn on the ignition and check the Terminal Velocity LED connection. It pre-heats the O2 sensor and blinks from red to green for 90 seconds then pops to a constant green indicating that the closed loop system is complete. We did the do, then we could finalize the replacing the side panels and bags.

Terry Components
http://www.terrycomp.com/
Toll Free: (866) 388-3779

12 choprod brkts

First we installed the Carlini Bag Rails to eliminate the crash bars. That took a set of torx sockets to remove the 3/8s fasteners from the frame and then two 5/16s bolts at the rear of the bag rails to drop the unit. The Carlini arm bolted up easily and the left hand bag fitted into place easier than ever before.

13 left of bike
Here’s the stock crashbar and bag arm in place.

On the right side of the bike the rubber bung had to be removed and replace from the stock bar arm to the Carlini job. Watch how it pushes out so you replace it in the same manner.

14 box on brkt
Not sure we have this on correctly. I checked. It's wrong–turn it upside down.

15 brkt installed

There you have it. Final King tuned, crash bars gone and True-Track holding it all together.

king right

Carlini Design
http://www.carlinidesign.com/
(714) 432-9000

hinnie shot
Keith Terry told me that after 50 miles his system would retune the King, the spark plugs and pipe would be cleaner, and I’d feel it in the seat of her pants. I hope so.

Please follow and like us:
Pin Share
Scroll to Top