Wiring issue I suspect on 77 dodge aspen with 302, t5, A9L. Starts then dies - Ford Mustang Forums : Corral.net Mustang Forum
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post #1 of 7 Old 04-26-2017, 01:13 AM Thread Starter
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Wiring issue I suspect on 77 dodge aspen with 302, t5, A9L. Starts then dies

24 hours of lemons racecar. Budget build because they have a very strict spending limit on your car. Anyways....

I got a 1990 (I think) mustang 302, sn95 t5, 1991 a9L (I rhink) and 1991 (I think) harness. Apparently all of the parts came from stick shift cars. And I have a couple different oxygen sensor harnesses (not using) And I have a 77 dodge aspen shell.

Anyway I put it all into the Aspen, did not use a transmission harness, no vss, no Evap no ac cut out, no fuel pump relay, no emissions, nothing that wasn't necessary. did not use an oxygen sensor harness. Sent "key on" 12v to both oxygen sensors and pinned the return signals and grounds directly to the computer like tmoss pinout diagram shows. Did not use any of the eec relays or anything on the harness no switches or sensors on clutch or tranny

Literally all I'm using is a barometric sensor, engine coolant temperature sensor (on the heater core pipe/rail), intake air temperature sensor (on the gt40 manifold), mass air sensor, both oxygen sensors, tps, idle speed bypass control thing, distributer with tfi mounted on it, and coil. I have everything wired up and triple checked and functioning somewhat properly. I followed Tmoss pin out diagram on only the necessary stuff. I sent "key on" 12v to pins 37, 57, The ignition coil positive side, the "run" lead on the distributor, maf, idle speed control, and all 8 injectors. "Start only" 12v to corresponding pin on distributer harness, made sure I used a 20 2K resistor right before the ECU on the corresponding wire I grounded all of the grounds. And pin 1 has a constant 12v volts for the Memory. I checked the tps voltage .92 or .94 I don't remember exactly which one. I just remembered checked out good

It fires right up and sounds great smooth and strong for 3 to 5 seconds until it shuts off. I can kind of keep it running by using the throttle. If I keep opening and closing the throttle real carefully it will rev up and die down and sputter and then rev up. Can barely keep it running using the throttle. I can occasionally get it to rev up to about 2 grand by feathering the throttle and it sounds great at 2 grand but it will not idle and to get to 2 grand I have to carefully feather the throttle open and closed a couple times and getting to 2 grand it is really choppy and sputters a lot. And then at like exactly 2 grand it sounds fantastic and then drops back down and dies. It won't idle on its own. It seems like when it first fires up the RPMs are good and high and then in a few seconds when the RPMs would want to drop down to Idle is when it doesn't do that and just shuts off

I did not do anything with pin 30. I have no jumper installed anywhere on the oxygen sensor harness because I'm not using one. I did not jump or bypass any other wires on the harness I simply left everything I'm not using unhooked and only hooked up what I am using. So I'm not sure if I need to do something with that pin 30 or if the computer thinks that the clutch is not Pressed in or that it is in gear or something I have no clue. The fuel system is a fuel-cell with adjustable fpr, in line pump wired to relay, and "key on". I've been trying to check and see if I'm losing injectors or the ignition signalnwhen it does, but it's hard to figure that out because when it dies you lose those signals anyway. Whether the computer is shutting off the injector pulse for some reason three seconds after start up. Or if the pip is doing something silly 3 seconds after start up.

For some reason and after reading a whole bunch of different posts about 1030 and 46. Jumpers on O2 sensor harnesses and all that other stuff I am leaning to believe that I need to jump something or cut something or bypass something. But then again at the same time i'm not sure that I need to do that because I don't have a vehicle speed sensor, no clutch switches, no NDS, none of that stuff. Literally have a battery switch a starter button and a couple engine sensors tied into the computer.

I've got to be missing something any help would be fantastic the races in two weeks the car still has to go get tuned and get an alignment

If anyone wants to call me and help me walk through something my number is 610-312-4269 I know sometimes people like to talk over the phone and explain things better than typing but any kind of responses that all would be fantastic

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post #2 of 7 Old 04-26-2017, 01:23 AM Thread Starter
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If anyone wants I can send videos of what it's doing. I have them on my phone don't know how to put them on here so text me if you want me to send a video to you of what it's doing

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post #3 of 7 Old 04-26-2017, 01:32 AM Thread Starter
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Am I supposed to ground pin 46 or 30 or somehow trick the EEC into thinking that a trans harness is installed with all the correct switches and all? I don't have a damn clue I am lost. I just need this thing to run so I can send it to get tuned and alignment asap. maybe I have the burned-out trace on the computer or something? Any responses for any tests to do or any wires to jump to anything would be great. Another note, it appears that pin number 30 from the EEC has a positive output of 5 V. Some people on other formus have said before to just attach pin 30 to pin 46. To me that would just create a dead short and fry something. But hell, what do I know I'm here asking questions trying to get my car to run LOL
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post #4 of 7 Old 04-26-2017, 09:05 AM Thread Starter
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I also did not use the factory low oil sensor or the oil pressure sensor. So right now there is no oil info getting back to the ecu. Ecu could be shutting it down since it doesn't have any oil input? But I didn't see any pins for either on the ecu so I didn't use them
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post #5 of 7 Old 04-26-2017, 10:31 AM Thread Starter
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Pin 46 with key on and ecu plugged in. Tested pin 46 to ground and have 5 volts. That good or bad?
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post #6 of 7 Old 04-28-2017, 12:44 AM
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that ecu doesn't look for oil info..
have you checked fuel pressure and timing ?

93 LX coupe 393 efi, on moth balls.
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post #7 of 7 Old 04-30-2017, 10:44 AM
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I suggest you use an EVTM for this, not made up internet diagrams

Tmoss diagrams, are good for a quick reference, but make assumptions that you know circuit design

pin 30 is a MONITOR, it just wants to know if the voltage is high or low

in auto it sees 12volts IN CRANK ONLY

in manual, if it sees 5v then the cruise is disabled

pin 46 is a sig rtn, a SENSOR ground, for the 5 volt ref circuit, DO NOT put 12volts to it...!!!

the sensors on the pin 46 circuit, pull the 5volts to ground and each pin that is the signal for that sensor is seeing how far to ground it is pulled, there are thermistors and pots on that circuit the pots have common 5 v ref feed and the signal is the wiper and the sig rtn is shared

you have to remember, a lot of circuits are shared internally within the ECM, like 5v ref, and grounds

89 GT gr-40, KB2200(10psi), tweecer R/T,LC-1, 22gal cell, w/tailpipes.
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