wolverine8490

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samseed101

When you did the sensor tests, did you do it with the neutral safety switch plugged in or no? I'd disconnect pin 30 for now and then add the other sensors 1 by 1 to see if you're getting anything. Obviously you're not going to get it to start and run this way, but it may help with figuring out the issue. Or did you already do that? Probably did, but I figured I'd ask just in case.

I guess it's possible that it is a fried computer, but it still really doesn't sound like it. It's behaving exactly as it would if a line was crossed and something was feeding voltage through that line. could even be a simple as a bad ground.

wolverine8490

Man, all the help is greatly appriciated. I mean I have spent no lie 24 hours going over everything. I think my plan of action today is going to be this:

Unhook all related wires at the EEC (7, 46, 47, 26, 45, and 30). Check for votage straight off the EEC and verify everything is what it is supposed to be. If not, throw the EEC at the next door neighbors house, and go buy a new one. If they are in check, then I am going to hook up the wiresone byone, test the lead off the sensor itself, verify the voltages, and do that one by one until I find the wire that sends voltage everywhere.

I think that will work at least [&:]

samseed101

Probably not a bad idea to unplug the wires themselves, that way it eliminates them from the equation (in case there is a short or crossed line somewhere.) Once htey're all disconnected, slowly reconnect them one by one.

I'd start with the TPS just for the hell of it. during this time, be sure to leave 30 disconencted. If you can get the TPS conected and you're not showing 4.9 on 46, then move on to the next sensor. If you ARE showing 4.9 after only reconnecting the TPS, then disconnect it and move on to the next sensor anyway. If you DID get 4.9 after connecting the TPS and you move on and see that the next sensor is fine, then you know to back up and retrace all the wires leading to the TPS. If you go on and find that the next sensor also shows 4.9 on the return line (46) then your problem lies elsewhere.

If you manage to get them all reconnected and then when you get to the BAP or anything that revolves around pin30 you see the voltage return, then you know where the problem is.

You should be able to track this down if you do them one at a time and stop when you see the first hint of a problem. When youy see the problem, disconnect the "problem sensor / wire", write it down, and move on to the next sensor. If you find no other problems, then you know where to focus your efforts.

wolverine8490

Ok,

Well I am still leaning towards the ECC. Here is what I found:

ECC per diagram:
7 - .5 @ 200 degrees F
25 - 3v @ 70 degrees F
46 - .1
47 - .9
26 - 4.9
45 - 159hz
30 - 4.9

ECC when unplugged:
7 - 4.9(sensor not plugged in and not at temp)
25 - 4.9 (sensor not plugged in and not at temp)
46 - .01
47 - .00
26 - 4.9
45 - 4.9
30- 4.9

As soon as I hooked any sensor wire back up, 47 recieved 4.9 volts, which should only be .9. I think I am just going to light the car on fire and call it a day.

samseed101

Those are some weird readings you're getting. I guess it really could be the computer, although I'd expect it to actually "burn out" and prevent any coltage from getting through, as opposed to sending a steady, set voltage down certain pins. But if every sensor causes the TPS to read 4.9v, I guess there is a major problem there! LoL

Joel5.0

Remove ECM, very carefully, check the resistance between pin 46 and pins 40 & 60 at the ECM .....if the resistance is > 5 ohms....the SIGRTN circuit on the ECM PWB is open/blown/burnt. LUK....BTW, it's "repairable".

wolverine8490

Ok, I will check that out.

So you mean check 46 to 40 and 46 to 60? Or 46 to 40 and 40 to 60. Sorry, I have seen so many numbers, I could tell you just about any color wire off the ECC without even looking right now.

As for if my ECC is dead. I can pick one up at Autzone for 96 bucks. But they do not know it by A9L or A9P. What should I tell them. The @$$hole that owned the car before me ripped the stickers off.

Thanks again everyone for all the help. I am just really starting to get very frustrated.

Joel5.0

46 to 40 and 46 to 60.....simply ask for a replacement ECM for a 1989 Mustang with a manual transmission (A9L) or #'s 784352 (Cardone), EEC1630 (Niehoff) or EM073 (Standard Motor)...or use oem #'s: F3ZF-12A650-DB, -DA, E9ZF-12A650-AA, -BA

wolverine8490

Man, you dont know how much that helped.. I will check the ECC tonight, and let you all know. I appriciate all the help again. I just got this thing put together, and I am anxious to get it all running right..