Click on our menu buttons immediately below to find MegaSquirt® information quickly:


TFI Ignition Control

Thick Film Ignition (TFI) modules were used on Ford vehicles with distributors from the early 1980s to the mid-1990s. It was used on a number of Ford's engines, the EFI 5.0 engines in particular. The TFI module is a gray box fitted to the side of the distributor. It is about one inch wide, and about four inches long. The distributor itself uses a Hall effect sensor.

The TFI modules are available as Holley 891-105 or Accel 35368 (~$46), as well as from a number of aftermarket sources.

Installing the Ford TFI System

Note: this information is tentative. The TFI setup has not been 100% verified yet.

First, be sure to use MicroSquirt code version 2.1 or higher. This code has the appropriate algorithm for the necessary 'trigger return' cranking parameter. Get the code here.

To install TFI with MicroSquirt, you:

The PIP signal comes into MicroSquirt on Ampseal pin 30, the SPOUT goes out on pin #12.

Then in TunerStudio, set:

Then set the maximum dwell duration to 8.0 milliseconds with no battery voltage compensation (set the five 'Duration at Voltage X' to 0.0 under 'Dwell Settings/Battery Voltage Compensation' in MegaTune.).



MegaSquirt® and MicroSquirt® controllers are experimental devices intended for educational purposes.
MegaSquirt® and MicroSquirt® controllers are not for sale or use on pollution controlled vehicles. Check the laws that apply in your locality to determine if using a MegaSquirt® or MicroSquirt® controller is legal for your application.
©2005, 2007 Bruce Bowling and Al Grippo. All rights reserved. MegaSquirt® and MicroSquirt® are registered trademarks. This document is solely for the support of MegaSquirt® boards from Bowling and Grippo.