Fox T-Bird/Cougar Forums

Technical => Electrical Tech => Topic started by: tireshredder on April 17, 2009, 08:02:28 PM

Title: Current draw
Post by: tireshredder on April 17, 2009, 08:02:28 PM
Ok, I know the car draws around 50 mA just sitting there, right?  Is that just for the radio, or for the computer too.  I had a .14 Amp draw on it, and as soon as a pulled the radio (aftermarket, if that makes a difference), the draw went away.... totally.  Meter reads 0.  I'm thought the computer would draw some too, right?
Title: Current draw
Post by: TurboCoupe50 on April 17, 2009, 08:09:43 PM
50ma is the upper limit, all I've checked have been less than 25ma... I too would have thought the EEC would draw a bit of current as well, but maybe not... If it's not giving a memory fail code (15 I believe), I wouldn't be concerned...
Title: Current draw
Post by: tireshredder on April 17, 2009, 09:20:20 PM
I'm trying to start a fresh engine, and I've gone mass air.  The engine will turn, but not fire, and I'm getting spark.  Thought the injectors weren't firing, but couldn't test it till I found the drain.  Was hoping I got two birds with one stone, but the noid light is going off now, so back to square one....
Title: Current draw
Post by: jcassity on April 18, 2009, 02:10:41 AM
anytime i see spark and fuel but no start,, tells me the stator is bad down in the distributor.

This has only happened to me twice though were I had the time to troubleshoot.
Title: Current draw
Post by: tireshredder on April 21, 2009, 12:23:14 PM
It was the radio.  Always acted funny anyway, turning off magically.
Title: Current draw
Post by: Beau on April 21, 2009, 01:58:25 PM
Radio kept the car from starting? ;)

Seriously, did you solve it?
Title: Current draw
Post by: tireshredder on April 21, 2009, 09:44:35 PM
Radio killed battery.  Which kinda killed the car. :P

Solved draw problem, but injectors still not working.  Was going to test fuel pressure, but now the d@$n fuel pump ain't working....

If this car was a woman, I'd ask for a divorce.
Title: Current draw
Post by: Beau on April 22, 2009, 02:14:43 AM
Quote from: tireshredder;268523
injectors still not working. Now the d@$n fuel pump ain't working....

;) :d
Title: Current draw
Post by: TurboCoupe50 on April 22, 2009, 12:49:33 PM
Quote from: tireshredder;268523
Was going to test fuel pressure, but now the d@$n fuel pump ain't working....


Probably your problem from the begnning...
Title: Current draw
Post by: tireshredder on April 22, 2009, 12:54:42 PM
It was priming fine until I went to test the pressure.  It's a new Walbro unit too. My brother and I think the relay went bad, cause the wire from it to the pump isn't getting power.  But it's just an guess for the most part.
Title: Current draw
Post by: TurboCoupe50 on April 23, 2009, 07:17:04 PM
Did you try resetting the inertia switch???
Title: Current draw
Post by: tireshredder on April 23, 2009, 08:03:21 PM
Of course.  New relay didn't work either.  I'm trying to find a wiring diagram for the fuel pump system so I can start testing (and know what I'm doing).

How many volts can the pump handle?  I want to test it, to see if that is the problem.
Title: Current draw
Post by: tireshredder on May 02, 2009, 09:28:22 PM
Ok, I've been back at it.  Inertia switch is fine.  If I jump the power wire to the fuel pump wire on the relay connector, it runs.  If I bypass the inertia switch, it doesn't.  I thinking now that the relay isn't getting the signal, so it's not switching on.  Anyone have an idea?
Title: Current draw
Post by: tireshredder on May 02, 2009, 10:55:56 PM
Ok, tested a couple wires on the connector from them to the ground.  Red wire -12V.  Yellow Wire-12V.  Tan/Green- 12V.  Pink/black- 0V.  I think thats right, but I've been wrong before.

And as a side note, the new relay has 5 connectors, but the old one only has 4.  It's the right part number (from the website anyway.)  Could this be messing it up?
Title: Current draw
Post by: softtouch on May 03, 2009, 02:16:04 PM
Put the old fuel pump relay back in. The new one having an extra connector is suspicious.

With the key in run without starting the pump should run for 1 or 2 seconds (priming).
If it does not run leave the key in run and jumper the T/LG wire in pin 6 of the self test connector to ground.

If the pump runs it means the EEC Power Relay, the Inertia Switch and the Fuel Pump Relay
 are all good but EEC did not provide ground for the pump relay when it was supposed to
prime.

BK/Y wire #175 and R wire #361 are tied together on the next page.




(http://mysite.verizon.net/vzetk5cc/sitebuildercontent/sitebuilderpictures/FuelPump87.jpg)
Title: Current draw
Post by: tireshredder on May 03, 2009, 04:37:22 PM
Thanks, did it and it primes.  Now I guess either I have a bad computer, or I mess up the wiring for the mass air...
Title: Current draw
Post by: softtouch on May 03, 2009, 05:05:43 PM
Quote from: tireshredder;270364
Thanks, did it and it primes.  Now I guess either I have a bad computer, or I mess up the wiring for the mass air...

Do you mean it primes without the jumper?
Title: Current draw
Post by: tireshredder on May 03, 2009, 07:53:26 PM
Sorry.  I meant I did the test.  Jumping it made the pump run.  Key still doesn't work.
Title: Current draw
Post by: softtouch on May 03, 2009, 08:33:48 PM
Will the car start if you leave the jumper on?
Title: Current draw
Post by: tireshredder on May 03, 2009, 09:01:03 PM
No.  Pressure got up around 40 when I tried it.
Title: Current draw
Post by: softtouch on May 03, 2009, 10:37:27 PM
Sounds like the EEC is bad.
Well let me rethink that.
You said earlier it pulsed the injectors. Is that still the case?
Title: Current draw
Post by: tireshredder on May 09, 2009, 08:28:31 PM
I was about to post they were, but then tested it, and sure enough.... no clicking...

It all happened after we took off the upper manifold to check the injectors.  But what could we have hit up there?
Title: Current draw
Post by: softtouch on May 10, 2009, 12:36:35 AM
Quote from: tireshredder;271451
It all happened after we took off the upper manifold to check the injectors.  But what could we have hit up there?

Don't know, but the ECC is not working for some reason.
The only thing I can think of other than it being bad is voltages and grounds.

Your negative battery cable should have a small BK/LG pigtail wire that goes to a one wire connector near the battery. This is the ground wire for the EEC. It goes to EEC pins 40 and 60.

The EEC also has a chassis ground on pin 20. This wire goes to the cowl near the EEC.

EEC pin 1 is hot at all times.
EEC pins 37 and 57 are hot in start or run.
Title: Current draw
Post by: softtouch on May 10, 2009, 12:55:56 AM
Did you use the write up in http://www.coolcats.net/tech/advanced/massair.html
to modify your 88 cable harness for mass air?
Title: Current draw
Post by: tireshredder on May 10, 2009, 10:19:25 AM
No, I bought the kit it mentioned and used the instructions that came with it.
Title: Current draw
Post by: TurboCoupe50 on May 10, 2009, 05:33:28 PM
If the TPS ground is open, the EEC will enter dechoke mode and shut down the injectors... Need to verify the voltage back to the EEC is at less than 1v... If it's over approx 4v, the injectors will be shut off...
Title: Current draw
Post by: tireshredder on May 14, 2009, 09:44:20 PM
Ok, all those pins check out.  Mass air wires have power to, so the wirings ok.
What pin is the TPS sensor?
Title: Current draw
Post by: jcassity on May 14, 2009, 09:58:32 PM
with the tps still plugged in,,,,,,,,

turn on key
ground your neg meter lead to chassis or engine
back probe the tps connector green wire
voltage should be less than 1VDC.
Title: Current draw
Post by: softtouch on May 15, 2009, 12:26:28 AM
Quote from: tireshredder;272367
Ok, all those pins check out.  Mass air wires have power to, so the wirings ok.
What pin is the TPS sensor?

Pin 47
Title: Current draw
Post by: tireshredder on May 15, 2009, 12:49:48 AM
Well, figured out the TPS problem.... brother unplugged the distributor.... why, I'll never know.... I'll still test it tomorrow.

So I guess that puts it back to bad ECU.  Fuel pump still doesn't prime.