1990 Ranger 2.3 to 302 EFI conversion


Choc007

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Hey guys. Ive come to pick your brains a little. I have searched articles and I am having trouble finding ones that fit my case.
I have a 1990 ranger 2.3 XLT with 2 wheel drive. I am familier with Ford 302s..Ive owned a few mustangs. I have a 1990 302 mild build ( comp cam, performer intake, roller rockers..etc). I am looking to swap with the full EFI going too. Engine harness and ECU harness. I am having trouble finding what wires I need to pin to maintian fuel pump, ignition, etc. In other words what do I keep from body harness...what goes.
I am running a C4 with shift kit. This is going to be a mild build that I can hit the streets and not worry to much. Any articles or info is much appreciate. Thanks in advance.
 


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RonD

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So you will be using a stand-alone EFI computer?

Or a Ford V8 computer for manual trans(C4 doesn't need computer control)

The 1990 should have setup like this: https://ww2-secure.justanswer.com/uploads/fordguy4u/2010-01-04_165627_A1.jpg

EEC Relay is activated by key on
It powers the fuel injectors, IAC Valve, MAF heater, EVAP solenoid, EGR solenoid, and it powers the Fuel pump relay "coil", not fuel pump
All these devices(except MAF heater) are controlled by the computer via GROUND wires, pulsed ground

1990 Ford computer GROUNDS the fuel pump relay to activate it, but only for 2 seconds when key is turned on, primes the fuel system
When computer sees RPMs above 400(engine started) it then GROUNDS fuel pump relay full time
You can just ground the FP relay so it comes on with the key

Have a look here at the wiring diagrams: https://therangerstation.com/tech_library/EDiagrams/index.htm

Ford V8 computer will have these ground controls

Power for ignition switch is just one wire from a Fusible link(on starter relay) or a larger fuse in the engine fuse box, usually a Yellow wire
 

Choc007

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Great question. I am using a manual ford v8 computer from a 1990 mustang GT. Thanks for the info. Definitely going to put it to good use.
 

RonD

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Diagram here of the V8 EEC-IV computer wiring: http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

You will need to provide full time 12v to pin 1, KAP, keep alive memory
Then hook pins 37 and 57 to output power from EEC Relay, boots computer up with key on

pins 20, 40, 60 and 49 need to be grounded

pin 22 grounds the fuel pump relay

1990 Ranger fuse box should have 3 60amp fuses
one is for the yellow wire that runs to ignition switch
two are for the alternator hook up

Two 30 amp fuses
One for EEC relay, the power it sends out
One for Fuel pump relay, power it sends to fuel pump

pin 17 is for the CEL(check engine light) it a GROUND when computer turns ON the CEL, so dash lbulb gets 12volts with key on full time
computer grounds pin 17 for boot up then ungrounds it after start up if all is well

The TFI spark system wire colors are the same for the Ranger,
red/blue wire, has 12v when key is turned to START, same wire is on starter relay(solenoid) inner fender
red/green wire, 12v from ignition switch in RUN and START, powers the spark system
 


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