88' Bronco II, 2.9ltr. Found that my Injectors aren't getting "pulse" signal from Computer...getting Voltage though. Refastened ALL Grounds on truck. Checked grounds on Computer Harness(there are 5)all had "0" Resistance, they're fine. Found that pin 26 is NOT getting "reference voltage" to my Throttle Position Sensor"...only 1 Volt! Wiring to TPS and harness at Tps is alright. Also, pin 26 supplys voltage to the MAP Sensor, brilliant idea there! When testing TPS voltage is supposed to be 0.5 at idle and go to between 4-4.5 volts at WOT. It's a half a volt and only goes to 3/4 of a volt at WOT. Know the Map Sensor isn't working right either being pin 26 supplys them both. Computer is NOT sending the 5 volts to tps or Map and i think because of that it's NOT firing the injectors. I'm grinding away trying to start the engine and the Computer thinks the truck is just sitting there with the key off. This is a real "PITA"! Anybody out there have any ideas i'd really appreciate hearing from you. Also, the fact i can't get any codes from my test connector has got me thinking my Computer is shot; it's the original one(25 years old).

 

Well, at least you have the problem narrowed down to the 5v supply. Unplug and plug back in the computer. Sometimes the big plug gets a bad connection in it. If that doesn't do it, see if you can find the 5v pin on the wiring plug, and see what ohm reading you get from it to ground, to make sure the wiring is not shorted. Other than that, it might be the computer.

Here's some places in California that have a used computer to fit.
1988
Engine Computer
Ford Ranger USED ON PC RACK AS-IS 6062 $200 All Ford Auto Salvage USA-CA(Anaheim) Request_Quote 714-993-2110 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II Ele Cont Unit (ECU), AT, CAL- B0424E $100 B-J Used Auto Parts & Dism. Inc USA-CA(Downey) Request_Quote 562-927-8621 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger EEC Cont (Processor), (2.9L), CAL, AT- 25% RESTOCKING FEE YARD $100 Steelhead Recyclers USA-CA(Goleta) Request_Quote 805-683-8557 / 866-314-0730 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II AT,CAL,ID E8TF-T1A 565428 $100 Tri County Auto Dismantlers USA-CA(Santa-Paula) Request_Quote 1-877-667-2787 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II Ele Cont Unit (ECU), AT, CAL-ID E8TFT1C 565484 $100 Tri County Auto Dismantlers USA-CA(Santa-Paula) Request_Quote 1-877-667-2787 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger E8 R1A 4X 2.9 RX48624 RX4862 $95 Truck Parts Company USA-CA(Baldwin-Park) Request_Quote 1-800-411-8718 (Cali only) 626-337-7264 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger ZP4860 E8 AVA zp4860 $95 Truck Parts Company USA-CA(Baldwin-Park) Request_Quote 1-800-411-8718 (Cali only) 626-337-7264 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II ga13106 2.9 auto e8 oc ga1310 $80 Truck Parts Company USA-CA(Baldwin-Park) Request_Quote 1-800-411-8718 (Cali only) 626-337-7264 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger 6-179 2.9 CAL E8TF-T1A- AS-IS A 006433 $75 Coast Auto Supplies and Dismantling, Inc. USA-CA(Watsonville) Request_Quote 1-831-722-5050 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II E8TF-T1C 5032 $75 Navarra Truck and Van Dismantlers USA-CA(San-Jose) E-mail 1-800-628-2772
1988
Engine Computer
Ford Bronco II E8TF-12A650-TC B2757 $70 Raymer Auto Parts USA-CA(Van-Nuys) Request_Quote 818-512-6100 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger A4LD,2.9L,E8TF-T1C 4155 $65 United Truck Dismantlers Inc. USA-CA(Marysville) Request_Quote 1-800-371-9555 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II E8TF 12A650 T1A-U E8TFT1 $65 Freeway Auto Wreckers USA-CA(Sacramento) Request_Quote 916-927-2421/888-367-3778 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II E8TF-12A650-T1A B1110 $60 Raymer Auto Parts USA-CA(Van-Nuys) Request_Quote 818-512-6100 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger E8TF-T1C $50 West Auto Wreckers USA-CA(Chula-Vista) Request_Quote 1-619-423-1100 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II 2.9 AUTO 25% RESTOCKING FEE A A50030 $50 P & C Auto Wreckers USA-CA(Milpitas) Request_Quote 1-800-772-8455 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger NO #S [590-02388] A SD0008 $50 Sierra Auto Recycling, Inc. USA-CA(Ridgecrest) Request_Quote 1-800-346-8733 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger Ele Cont Unit (ECU), ID#E8TF-12A650-T1C A 12P4202 $49.99 U Pick U Save-Anaheim USA-CA(Anaheim) Request_Quote 714-934-8310 ext. 128 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger ID#E8TF-12A650-T1A Ele Cont Unit (ECU), 6-179 (2.9L), CAL, AT A 13P0135 $49.99 U Pick U Save-Anaheim USA-CA(Anaheim) Request_Quote 714-934-8310 ext. 128 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II Ele Cont Unit (ECU), AT, CAL ID#E6TF-12A650-M2C A 12G? $49.99 U Pick U Save-Anaheim USA-CA(Anaheim) Request_Quote 714-934-8310 ext. 128 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II Ele Cont Unit (ECU), AT, CAL ID#E8TF+12A650-T1C A 12G? $49.99 U Pick U Save-Anaheim USA-CA(Anaheim) Request_Quote 714-934-8310 ext. 128 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger 88 RANGER 2.9 ECM NO NUMBERS E80003 $Call Dorris Auto Wreckers, Inc. USA-CA(Hayward) E-mail 1-510-782-4393/1-510-782-4394
1988
Engine Computer
Ford Ranger EEC Cont. (Processor), (2.9L), CAL., A. 2388 $Call Greer Auto Wreckers USA-CA(San-Jose) Request_Quote 1-800-989-7278 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II Ele Cont Unit (ECU), AT, CAL- C88659 $Call A & M Auto Dismantler USA-CA(Stockton) E-mail 1-209-982-4146
1988
Engine Computer
Ford Ranger E8TF-12A650-T1A NOF $Call Bob Wescott's Auto & Truck - SCADA USA-CA(Santa-Rosa) Request_Quote 1-707-542-0311 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II ENGINE CONTRL MODULE E8TF-12A650-T1C A 110077 $Call Rancho Ford Truck USA-CA(Rancho-Cordova) Request_Quote 800-434-2222 / 916-638-2222 Request_Insurance_Quote
1988
Engine Computer
Ford Bronco II 2.9L AT CA ECM E9TF-12A650-J1B A BBNOF $Call Rancho Ford Truck USA-CA(Rancho-Cordova) Request_Quote 800-434-2222 / 916-638-2222 Request_Insurance_Quote
1988
Engine Computer
Ford Ranger ident: E8TFT1C A 6568 $Call Max Auto Salvage USA-CA(Arroyo-Grande) E-mail 805-343-5552
1988
Engine Computer
Ford Ranger Ident: E8TF12A650T1A A 8483 $Call Max Auto Salvage USA-CA(Arroyo-Grande) E-mail 805-343-5552