86 12 Brutus Posted January 19, 2023 Share Posted January 19, 2023 Ok. Thanks at all. I will start on Saturday by checking, respectively testing the injectors as you have mentioned. After that, I will un-tape the harness of the ECU and set new cable to it. Independently to the test, the error can also be made by the ECU, based on wrong input data of the sensors, in my opinion. So not only caused on the output side of the ECU, maybe also effected by some inductive or capacitive wrong input... If the harness isn't the problem...I will get mad...it's the last thing I haven't replaced... Based on everything i read here, Gary is right it most likely is the wiring. When we restored Brutus, Nick made all new harness's for everything inside and out. You would be surprised at how much bad wire was pulled out of that truck and Nick is the original owner. I wish you good luck. Link to comment Share on other sites More sharing options...
85lebaront2 Posted January 20, 2023 Share Posted January 20, 2023 Based on everything i read here, Gary is right it most likely is the wiring. When we restored Brutus, Nick made all new harness's for everything inside and out. You would be surprised at how much bad wire was pulled out of that truck and Nick is the original owner. I wish you good luck. Let me tell you about wiring, the 1985/86 EFI trucks I have dealt with had the crappiest condition wiring I had seen since helping restore some 55-57 T-Birds. Those had the old rubber/cloth insulation, cloth would fray or rot, rubber turned to a hardness and brittleness of Bakelite. When we bought a 1955 Packard Patrician to restore (my late wife grew up with Packards) I was pleasantly surprised to find why GM snapped up Packard Wire and Cable. All wiring other than accessories was color coded and numbered with Hypalon insulation. Still fully flexible nearly 30 years later. The accessories (light sockets, blower motors etc.) were either AC Delco or Autolite and had rubber/cloth insulation that had to be handled very carefully or it crumbled. I will not be at all surprised if the wiring is the problem. Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 20, 2023 Share Posted January 20, 2023 Let me tell you about wiring, the 1985/86 EFI trucks I have dealt with had the crappiest condition wiring I had seen since helping restore some 55-57 T-Birds. Those had the old rubber/cloth insulation, cloth would fray or rot, rubber turned to a hardness and brittleness of Bakelite. When we bought a 1955 Packard Patrician to restore (my late wife grew up with Packards) I was pleasantly surprised to find why GM snapped up Packard Wire and Cable. All wiring other than accessories was color coded and numbered with Hypalon insulation. Still fully flexible nearly 30 years later. The accessories (light sockets, blower motors etc.) were either AC Delco or Autolite and had rubber/cloth insulation that had to be handled very carefully or it crumbled. I will not be at all surprised if the wiring is the problem. Somewhere in that wiring Bank 1 and Bank 2 are shorted. Link to comment Share on other sites More sharing options...
86 12 Brutus Posted January 20, 2023 Share Posted January 20, 2023 Let me tell you about wiring, the 1985/86 EFI trucks I have dealt with had the crappiest condition wiring I had seen since helping restore some 55-57 T-Birds. Those had the old rubber/cloth insulation, cloth would fray or rot, rubber turned to a hardness and brittleness of Bakelite. When we bought a 1955 Packard Patrician to restore (my late wife grew up with Packards) I was pleasantly surprised to find why GM snapped up Packard Wire and Cable. All wiring other than accessories was color coded and numbered with Hypalon insulation. Still fully flexible nearly 30 years later. The accessories (light sockets, blower motors etc.) were either AC Delco or Autolite and had rubber/cloth insulation that had to be handled very carefully or it crumbled. I will not be at all surprised if the wiring is the problem. Yes indeed Bill, i concur, just ask Brutus. We had a double wammy , being he is a half year special edition truck, we have the joy of 86, 87, 80 and 79 wire harness Link to comment Share on other sites More sharing options...
ReneH Posted January 21, 2023 Author Share Posted January 21, 2023 Somewhere in that wiring Bank 1 and Bank 2 are shorted. Hi. So I have checked again the resistance between both wires of the injector banks...what should I say... 7 ohms...so they have contact...I have done this many times without getting any resistance...so it's definitely the wiring. Tomorrow I will open all isolation tapes and get the singe wires out. So I also get their physical route. The one of the connectors I don't know for what it is is also directly connected to the EFI-System...same wire colors...so this connector is maybe for testing the injectors... I will keep you up to date, tomorrow when I'm starting... Link to comment Share on other sites More sharing options...
85lebaront2 Posted January 21, 2023 Share Posted January 21, 2023 Hi. So I have checked again the resistance between both wires of the injector banks...what should I say... 7 ohms...so they have contact...I have done this many times without getting any resistance...so it's definitely the wiring. Tomorrow I will open all isolation tapes and get the singe wires out. So I also get their physical route. The one of the connectors I don't know for what it is is also directly connected to the EFI-System...same wire colors...so this connector is maybe for testing the injectors... 20230121_161401.jpg I will keep you up to date, tomorrow when I'm starting... That connector may be C160, and is probably near the back of the engine. With it unplugged, and key on, you should have power at the injector wires. Grounding either one it should activate 4 injectors (either end or center). Link to comment Share on other sites More sharing options...
Gary Lewis Posted January 22, 2023 Share Posted January 22, 2023 Hi. So I have checked again the resistance between both wires of the injector banks...what should I say... 7 ohms...so they have contact...I have done this many times without getting any resistance...so it's definitely the wiring. Tomorrow I will open all isolation tapes and get the singe wires out. So I also get their physical route. The one of the connectors I don't know for what it is is also directly connected to the EFI-System...same wire colors...so this connector is maybe for testing the injectors... 20230121_161401.jpg I will keep you up to date, tomorrow when I'm starting... Now THAT is PROGRESS! Link to comment Share on other sites More sharing options...
ReneH Posted January 22, 2023 Author Share Posted January 22, 2023 Hi. So I have checked again the resistance between both wires of the injector banks...what should I say... 7 ohms...so they have contact...I have done this many times without getting any resistance...so it's definitely the wiring. Tomorrow I will open all isolation tapes and get the singe wires out. So I also get their physical route. The one of the connectors I don't know for what it is is also directly connected to the EFI-System...same wire colors...so this connector is maybe for testing the injectors... 20230121_161401.jpg I will keep you up to date, tomorrow when I'm starting... Ok... I have done a capital mistake... Measuring the resistance between bank one and two will always result 7 ohms... You ask why? 14 ohms per injector (inductor). 4 injectors parallel on one bank = 3.5 ohms per bank. Both banks share the plus connection. So both banks are in series if measuring from one GND to the other. 2x3.5 ohms = 7 ohms. So this resistance is correct...that wasn't the error... Link to comment Share on other sites More sharing options...
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