Originally Posted by
xctasy
The back ground is that Fords EECIV was a home run for Ford.
4th base, as it were.
EECIV was better than cutting edge NASA spec in its Motorolla processor, but it has all the earlier EECIII items of a dedicated ignition system. The only major change was the refernece voltage. On the EECIV, if you change the ignition, and it no longer works at all, it is because it needs a sub 5 volt signal, and the PIP and SPOUT have to follow Fords EECIV system 100%. I know that this is what keeps your car from starting.
We need to step back a little.
Base 4: EECIV, its an Ignition, Fuel and EGR control computer, three things, three bases covered, exactly what the ultra advanced 1980-1984 EECIII used on the CFi 5.0 was. EECIII in the CFi cars (and to a lessor extent, the Variable Venturi 2-bbl and Motorcraft 2150 2-bbl in 351K's, 351M's and 400 Fords) were 3 rd base systems, which on the carb cars, didn't have Fuel Control like the CFi did.
EECIV Ignition is the same essentially as the 5.0 CFi EECIII, a Speed Density system with the Dearborn guys coppying the EECIII algorithms over to EECIV, but its all packaged up to use the TFi as a Crank Postion Sensor (CPS).
Base 3: All EECIII's had a CPS, and a gutted Duraspark II distributor, called a Duraspark III.
Base 2 was the Ignition and Idle Fuel control EECII/ MCU Variable Venturi, with the earlier 1975-1978 Durasaprk I in 1978-1979 Califonia Fox Body Fairmont and X shell Granada/Monarch/Versailies. The EECII controlled air-fuel ratio via the Ford proprietary model 7200 Variable Venturi (VV) Carburetor. Ignition, EGR, two things, but with a very advanced higher energy early Duraspark I with Red strain relief to pass stringent CARB CA emissions standards.
The MCU cars were similar, the common old 1-bbl 4 cylinder 2.3 OHV and 6 cylinder 4.9 Liter in line trucks, the Turbo and non Turbo 2-bbl Fox 2.3 OHC, the CA market 4.2/5.0 and later 3.8 V6 cars before EECIV and CFi were kind of EECII. Timing can be pulled out via knock sensor.
Base 1 was the EEC 1 on board computer used in the 1978 Lincolns, as of mid year 1978. Very much the same as the California 1979 version, but with Duraspark II ignition. Ignition, EGR, two things
Base 4 was the refining of all the field information Ford captured from the production EECI, II, and III cars....the EECIV was the home run system that integrated everything together with a TFi module that was no longer as big as a big brown Talmud or Bible like the EECIII's Duraspark III control unit was.
No one understands the Duraspark III or TFi systems really well, so you have to go over the TFi related stuff supplied to you in the MSD hand book, and it has to have the right Prox meter signal to enliven the EECIV's reference square wave signal.
The stock Ford sensors in the TFi are very reliable, but grounding issues comfund and confuse a lot of people. When you swap to an MSD, you can only use a system that supplies the EECIV the vital information.
My bet is the system is not compatible, and you need a little bit of help.
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