fords4life Posted July 25, 2018 Author Share Posted July 25, 2018 Piercing the wire will lead to moisture intrusion and eventually corrosion. If you slide a paperclip alongside the lead you wish to check at the EEC connector plug (easiest way on yours, pull the EEC out of it's mount so you can reach it better). The pins you want SPOUT 36, PIP 56, these are the ignition distributor to EEC and return. If you need more let me know. Thank you. Found someone local who might have a breakout box. I should know this weekend. BTW... Got home tonight and she fired right up.... Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 25, 2018 Share Posted July 25, 2018 Thank you. Found someone local who might have a breakout box. I should know this weekend. BTW... Got home tonight and she fired right up.... Naturally, what else did you expect? Link to comment Share on other sites More sharing options...
fords4life Posted July 26, 2018 Author Share Posted July 26, 2018 Naturally, what else did you expect? So it rained last night....yup...you guessed it....truck didn't start. I was able to get my DVOM onto pin 36 on the back side of the connector and check voltage to ground while cranking. Voltage was 4.8v to 5.0v. The only thing I'm not sure of is how to simulate the breakout box being in the "computed" position for timing. Can I pull the spout connector by the distributor? I am going to try and pick up a manual fuel pressure gauge and adapter for the fuel rail so I can verify that I'm getting enough fuel pressure. Link to comment Share on other sites More sharing options...
Gary Lewis Posted July 26, 2018 Share Posted July 26, 2018 So it rained last night....yup...you guessed it....truck didn't start. I was able to get my DVOM onto pin 36 on the back side of the connector and check voltage to ground while cranking. Voltage was 4.8v to 5.0v. The only thing I'm not sure of is how to simulate the breakout box being in the "computed" position for timing. Can I pull the spout connector by the distributor? I am going to try and pick up a manual fuel pressure gauge and adapter for the fuel rail so I can verify that I'm getting enough fuel pressure. I would think that dampness would cause low-level, meaning low voltage or low current, electrical problems rather than high current ones. And the fuel pump should be a high current device. In other words, if it is running then I don't think fuel pressure is the problem. If you have fuel pressure then I'd bet that you can ignore the fuel pump part of the problem solving. But I'll defer to Bill on that as well as the rest of the questions. Link to comment Share on other sites More sharing options...
fords4life Posted July 26, 2018 Author Share Posted July 26, 2018 I would think that dampness would cause low-level, meaning low voltage or low current, electrical problems rather than high current ones. And the fuel pump should be a high current device. In other words, if it is running then I don't think fuel pressure is the problem. If you have fuel pressure then I'd bet that you can ignore the fuel pump part of the problem solving. But I'll defer to Bill on that as well as the rest of the questions. I would agree, but at this point, figured knowing what the pressure is would at least 100% eliminate that. Like I mentioned previously, fuel is definitely flowing, you can hear it, and if I depress the schrader valve, fuel comes out with the Key On. I just can't confirm if I have adequate pressure. Link to comment Share on other sites More sharing options...
1986F150Six Posted July 26, 2018 Share Posted July 26, 2018 I would think that dampness would cause low-level, meaning low voltage or low current, electrical problems rather than high current ones. And the fuel pump should be a high current device. In other words, if it is running then I don't think fuel pressure is the problem. If you have fuel pressure then I'd bet that you can ignore the fuel pump part of the problem solving. But I'll defer to Bill on that as well as the rest of the questions. Electronics is not my strong point, but I am reminded of an issue I had years ago. My 1986 has been converted to Duraspark and the used replacement distributor had wires been cut, so there was no 3 wire connector [green, violet and black wires]. The distributor wires and the wiring harness were connected using blade connections, which worked. Later, I replaced the distributor [new], which had the female connector, but the wiring harness still had the blade connectors which were attached to the distributor connector. Damp conditions created no start intermittently. Keep in mind that on a 6 cylinder, this electrical connection is down low, where road spray is abundant. The connections were cleaned and liberal use of dielectric grease solved the problem. Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 26, 2018 Share Posted July 26, 2018 I would think that dampness would cause low-level, meaning low voltage or low current, electrical problems rather than high current ones. And the fuel pump should be a high current device. In other words, if it is running then I don't think fuel pressure is the problem. If you have fuel pressure then I'd bet that you can ignore the fuel pump part of the problem solving. But I'll defer to Bill on that as well as the rest of the questions. I would agree, but at this point, figured knowing what the pressure is would at least 100% eliminate that. Like I mentioned previously, fuel is definitely flowing, you can hear it, and if I depress the schrader valve, fuel comes out with the Key On. I just can't confirm if I have adequate pressure. You should be able to hear at least two pumps running, one in the tank(s) and one on the frame. If the frame pump runs but not the in-tank, you will get pressure but not adequate volume, in tank only not enough pressure or volume as it would have to pass the frame pump with it stationary. On your diagnostic connector on the right front (near the solenoid valves) if you ground the T/LG wire, this will turn on the fuel pump relay and run the pumps. From under the truck you should at a minimum be able to feel the vibration on the in-tank pump and maybe even hear it. The frame pump should be reasonably easy to hear particularly if it has been replaced (the original Bosch pump was pretty quiet). If they are all running, try the old "wiggle" test, shake the relay plug wiring and the frame pump wiring and the plug near the frame pump, you are dealing with 32+ year old wiring and not super well weatherproofed at that. Once again, I can not stress enough, check that ground connector, the pumps ground through the rear harness plug under the hood to G701 inside the cab near the EEC. The remainder of the system grounds at the battery through that double blade connector. Link to comment Share on other sites More sharing options...
fords4life Posted July 29, 2018 Author Share Posted July 29, 2018 You should be able to hear at least two pumps running, one in the tank(s) and one on the frame. If the frame pump runs but not the in-tank, you will get pressure but not adequate volume, in tank only not enough pressure or volume as it would have to pass the frame pump with it stationary. On your diagnostic connector on the right front (near the solenoid valves) if you ground the T/LG wire, this will turn on the fuel pump relay and run the pumps. From under the truck you should at a minimum be able to feel the vibration on the in-tank pump and maybe even hear it. The frame pump should be reasonably easy to hear particularly if it has been replaced (the original Bosch pump was pretty quiet). If they are all running, try the old "wiggle" test, shake the relay plug wiring and the frame pump wiring and the plug near the frame pump, you are dealing with 32+ year old wiring and not super well weatherproofed at that. Once again, I can not stress enough, check that ground connector, the pumps ground through the rear harness plug under the hood to G701 inside the cab near the EEC. The remainder of the system grounds at the battery through that double blade connector. Just a little more info. I've tried doing some of the diagnostics without the breakout box and I'm not real confident in the results. I did confirm that I'm building 40psi of fuel pressure. So I have fuel and I have spark so the only thing left is the injectors. I'll look at those tomorrow as long as the truck still isn't running.... Also confirm inertia switch and clutch safety switch are good. Link to comment Share on other sites More sharing options...
85lebaront2 Posted July 29, 2018 Share Posted July 29, 2018 Just a little more info. I've tried doing some of the diagnostics without the breakout box and I'm not real confident in the results. I did confirm that I'm building 40psi of fuel pressure. So I have fuel and I have spark so the only thing left is the injectors. I'll look at those tomorrow as long as the truck still isn't running.... Also confirm inertia switch and clutch safety switch are good. Inertia switch will kill the fuel pumps, that's what it is for, to shut off the fuel supply in an accident. The injectors are grouped 1458 and 2367 so #5 is on inj 1 (EEC pin 58) and #6 is on inj 2 (EEC pin 59). Circuit #361 (red) provides the power from the EEC power relay (next to the EEC) to the EEC and all the controlled components (solenoid valves, IAC and injectors) there is a connector, C160, in the engine feed section, the EVTM does not give it's location, but it is probably near the firewall grommet where the EFI harness comes through from the inside. Hope this helps. Link to comment Share on other sites More sharing options...
fords4life Posted August 1, 2018 Author Share Posted August 1, 2018 Just a little more info. I've tried doing some of the diagnostics without the breakout box and I'm not real confident in the results. I did confirm that I'm building 40psi of fuel pressure. So I have fuel and I have spark so the only thing left is the injectors. I'll look at those tomorrow as long as the truck still isn't running.... Also confirm inertia switch and clutch safety switch are good. Well a solid resolution continues to evade me. I keep running into tests that I really need a breakout box for so I ordered one. Well 2 actually. Found a pair on Ebay for less than $100 bucks shipped. I'll be posting up the second one for sale when it gets here if anyone is interested. I could replace the ECM and TFI and see what happens, but I hate throwing money at parts only to find it's in the wiring.... Link to comment Share on other sites More sharing options...
Recommended Posts