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Topic: 84 fuel pump issue (Read 2647 times) previous topic - next topic

84 fuel pump issue

Reply #15 –
Quote from: Pigpen52;232431
The pumps do not run...so what would the test connector look like..I am guessing it is just an unconnected connector close to the eec... thanks for the help so far...


It is a six pin connector with one row of two and one row of four.
On the 3.8 it is under the hood near the driver's side strut tower.

84 fuel pump issue

Reply #16 –
Death awaits you all with nasty, big, pointy teeth.

1988 5.0 Bird, mostly stock, partly not, now gone to T-Bird heaven.
1990 Volvo 740GL. 114 tire-shredding horsies, baby!

84 fuel pump issue

Reply #17 –
Ok...I grounded that out. and the pumps ran...sooo...what now?...thanks for the pics...it helped..now if I could just get a pic of the car running...thanks for the help so far...

84 fuel pump issue

Reply #18 –
good,,
now the next step (hope you dont mind softtouch)


Key off Engin off

remove the jumer wire you have at the eec self test connector.
find the same color wire on your fuel pump relay.
probe the wire with a stick pin
use a jumper wire to go from fhe stick pin to a good frame ground on your car.

Turn on your key

does the pump run now?

If it does,, fess up to whos been back there tinkering, they have shorted your EEC out and the computer can no longer deliver a ground to your fuel pump relay.


The fix

with the tan / light green wire grounded out **ALL THE TIME*** had no adverse effects on my pervious 3.8.

the only differences were, :
I turn on my key and the pump runs full time.
I run my car and the pump still runs like normal
I turn off my car and the pump runs for about 10sec then shuts off.

basically, the pump was waiting for the eec relay to shut off to kill power to the pump.

84 fuel pump issue

Reply #19 –
jcassity, I think he already tried what you are suggesting when he bypassed the pump relay to keep pump running and the car still wouldn't start.

pigpen, jcassity is right, the EEC is not providing the ground for the pump relay. The EEC is probably bad. Any chance the under dash wiring has been haywired or is it still virgin?

Try pulling computer codes. This will tell us if that part of the computer is still alive.
Post #2 in this thread shows how to do it. KOEO means key on engine off.

http://www.foxtbirdcougarforums.com/showthread.php?t=8897&highlight=pull+codes

The EEC is behind the passenger side kick panel.

84 fuel pump issue

Reply #20 –
Ok...will try that when I get home...just one more question (for now) why would it not start when I bypass the relay and force the pumps to run?

84 fuel pump issue

Reply #21 –
It could be because the EEC is bad. It controls the fuel injectors.
If you have a test light you could probe the tan wires at the injectors and see if it blinks while cranking. If the EEC is not working the light should stay on solid.
What engine do you have? 3.8 V6 or 5.0 V8

84 fuel pump issue

Reply #22 –
3.8  hopefully will be able to pull the codes tonight...just curious..does it matter that the battery has not been holding a charge?...I mean will that effect the codes? Where would you get an EEC and about how much are they?

84 fuel pump issue

Reply #23 –
Ok...when I tried to read the codes... I would get 12 volts with the key off...when I turned the key on it would got to 3 volts and not change...am I doing something wrong?

84 fuel pump issue

Reply #24 –
Quote from: Pigpen52;232748
Ok...when I tried to read the codes... I would get 12 volts with the key off...when I turned the key on it would got to 3 volts and not change...am I doing something wrong?


If you have the jumper on and the meter hooked up as shown that's all there is to it.
The voltage should drop to zero when you turn the key on. Then it should pulse up to 12 volts with the code pattern. Sounds like another indication that the EEC is bad.

If you had 12v when you tried to pull codes it should have worked.
You should try to get an EEC from an 86 or 87  3.8 CFI. They have some improvements over the 84 and 85.

I don't know if they are available anywhere other than a junkyard.
No idea what it will cost.
Maybe someone else can help here.

84 fuel pump issue

Reply #25 –
If he grounds out the eec at the fuel pump relay in the trunk and the car does not run,,,,,,,,,, IT tells us there is a broken wire from the eec to the fuel pump relay,,, but no break from the eec splice point out to the eec self test connector.
Still one more probable fault to check i would think since the eec self test conn tan/light green wire is just a branch circuit of the load.

If the car does run then.......
there are no options for him except opening up the eec and making the repair.

EEC is bad.

Leaving it grounded at the trunk is a work around with no real ill effects until he locates an eec. That was a suggestion i offered because I had to do it myself on the old motor.

Sorry, at that time, i did not see anywhere in his posts where he said he tried to start the car.

Ill assume that post 12 is when the eec got fried.  Not doing this properly will fry the eec.  I read post 12 front to back about a dozen times trying to figure out what was being said.  I can only assume the worse case senerio based on what was said. 


PigPin52-
did you prob or troubleshoot the fuel pump relay prior to coming here for help?  If so,, just keep in mind, bypassing or inerting power into the incorrect point on the relay may have spiked the eec right up the ground side of the computer with 12v.

84 fuel pump issue

Reply #26 –
ok...I am pretty sure I hooked it up exactly like the diagram said...so I assume the eec is bad...on when I jumpered the connection at the fuel pump relay, I just made a jumper and went from the constant hot wire for the pump, to the pump...did not mess with the control side of the relay...  Now since I can jumper the test wire at the front of the car and have the fuel pumps run I assume there is not a bad wire or connection...right?  SO..now to find an ecc...this is starting to get expensive...wish I could just put a carburator on it...will a 4412 bolt on?...lol

84 fuel pump issue

Reply #27 –
Quote from: Pigpen52;232814
Now since I can jumper the test wire at the front of the car and have the fuel pumps run I assume there is not a bad wire or connection...right? 



no sir
scroll back up and read the begining of my last post, there is still hope that this is a simple problem.
What color wires did you jumper on purpose and by accident at the fuel pump relay?

84 fuel pump issue

Reply #28 –
Quote from: Pigpen52;232814
ok...I am pretty sure I hooked it up exactly like the diagram said...so I assume the eec is bad...on when I jumpered the connection at the fuel pump relay, I just made a jumper and went from the constant hot wire for the pump, to the pump...did not mess with the control side of the relay...  Now since I can jumper the test wire at the front of the car and have the fuel pumps run I assume there is not a bad wire or connection...right?  SO..now to find an ecc...this is starting to get expensive...wish I could just put a carburator on it...will a 4412 bolt on?...lol


It can be changed to carb. It would require a different distributor and ignition system. You would have to bypass the high pressure fuel pump.
Try shopping around here and see what you can find.
http://car-part.com/

84 fuel pump issue

Reply #29 –
Sorry it took so long to reply...I belive it was the yellow and pink wires that I jumpered...did not mess with the control wire side of the relay... 

Softtouch...I was more curious if the holley two bbl. would bolt straight up..(cause if nothing else I am going to put a carb. on this thing and put it in a pure stock class at the dirttrack).I doubt the pump in the tank could keep up..so I would guess I would have to use a regulator(or change to a low pressure secondary pump....but why would I have to change ignitions?  It will run if I put gas straight down the throttle body....