Justfixit Posted July 25, 2021 Author Share Posted July 25, 2021 The main ECM ground attaches directly to a pigtail on battery negative. This is what's used to ground the injectors, so if this connection goes flakey the injectors won't open. You're right, Gary, in that the TFI modules are known to overheat. The vehicle will stall when called on to accelerate. Sometimes they come back when it cools down. There were even lawsuits about this. Problem found. There are two identical plugs that are long enough to go to the ground at the battery and they had the wrong one plugged in still trying to figure out where the other one goes to. Thank you for the help Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 25, 2021 Share Posted July 25, 2021 Problem found. There are two identical plugs that are long enough to go to the ground at the battery and they had the wrong one plugged in still trying to figure out where the other one goes to. Thank you for the help That's great, it was an easy fix! Often you can identify a circuit by the wire colour. Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 25, 2021 Share Posted July 25, 2021 Problem found. There are two identical plugs that are long enough to go to the ground at the battery and they had the wrong one plugged in still trying to figure out where the other one goes to. Thank you for the help Excellent! And Jim is right, what wire colors are in the other plug? Link to comment Share on other sites More sharing options...
Justfixit Posted July 25, 2021 Author Share Posted July 25, 2021 The main ECM ground attaches directly to a pigtail on battery negative. This is what's used to ground the injectors, so if this connection goes flakey the injectors won't open. You're right, Gary, in that the TFI modules are known to overheat. The vehicle will stall when called on to accelerate. Sometimes they come back when it cools down. There were even lawsuits about this. One is black one is black with white tracer. They are both ground wires but one of the plug halves was missing so I had to go to the scrap truck and steal one off of it , runs like a champ now Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 25, 2021 Share Posted July 25, 2021 One is black one is black with white tracer. They are both ground wires but one of the plug halves was missing so I had to go to the scrap truck and steal one off of it , runs like a champ now Black/White is used here: Power in Ckt 526 from Fuse Link P to trailer lamps Power from Fuse 12 in Ckt 171 to power door locks and mirrors Ckt 359 which connects the TPS, EJP, MAP, ECT, Air Charge Temp Sensor, & Knock Sensor to pin 46 on the ECU Power to the windshield washer pump via Ckt 941 from the wiper switch Link to comment Share on other sites More sharing options...
ArdWrknTrk Posted July 25, 2021 Share Posted July 25, 2021 Black/White is used here: Power in Ckt 526 from Fuse Link P to trailer lamps Power from Fuse 12 in Ckt 171 to power door locks and mirrors Ckt 359 which connects the TPS, EJP, MAP, ECT, Air Charge Temp Sensor, & Knock Sensor to pin 46 on the ECU Power to the windshield washer pump via Ckt 941 from the wiper switch IDK the details, but for many of these trucks a single black/white wire is stator power to the choke coil on the carburetor. Glad you've got it figured out. Link to comment Share on other sites More sharing options...
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