fuel pump problems

Topic: fuel pump problems (Read 7881 times) previous topic - next topic

fuel pump problems

January 16, 2010, 07:16:29 PM

my cougar cranks but no fuel is going to the fuel injectors. i dont hear the inline and in tank pump turn on with the key in the start position. what could be wrong? could both fuel pump out at the same time?

fuel pump problems

Reply #1 – January 16, 2010, 10:26:30 PM

1- check the little ground wire up near the battery

2- ground the tan / light green wire either on your EEC self test connector or on the fuel pump relay in the trunk.

turn on key,,listen for pump.

report back.

on an 84 model with two pumps, my advice may not be correct since its likely your running an EECIII system. If so let us know that as well.

fuel pump problems

Reply #2 – January 17, 2010, 01:04:57 AM

84 is EEC IV

fuel pump problems

Reply #3 – January 17, 2010, 12:00:41 PM

Did you check the inertia switch and the fuel pump relay? Seems like a slim chance of both pumps taking a at the same time, more likely to be something electrical.

fuel pump problems

Reply #4 – January 17, 2010, 12:27:35 PM

I agree with the inertia switch always check that first..

fuel pump problems

Reply #5 – January 18, 2010, 12:03:27 AM

where would my inertia switch be. i thought they were only on the 5.0 not the v6's. the ground wire your talking about is it the small one that connects to the negative cable on the battery?

fuel pump problems

Reply #6 – January 18, 2010, 01:04:27 AM

Quote from: blackcougar71;306728

where would my inertia switch be. i thought they were only on the 5.0 not the v6's.

Nope they all have one.

Quote

the ground wire your talking about is it the small one that connects to the negative cable on the battery?

Yep, That's the one jcassity is talking about.
It is the ground for the EEC computer. The EEC turns on the fuel pump by providing the ground for the fuel pump relay.

Ground the tan wire at the Self Test connector and turn the key on.(like jcassity suggested).
If the pumps run it means the EEC is not doing it's thing.

If the pumps don't run the problem is betwen the EEC and the pumps. Like the fuel pump relay and the inertia switch. The inertia switch has a reset button to reset it if it is tripped.

Some pictures:

fuel pump problems

Reply #7 – January 18, 2010, 10:31:47 AM

Quote from: blackcougar71;306728

where would my inertia switch be. i thought they were only on the 5.0 not the v6's. the ground wire your talking about is it the small one that connects to the negative cable on the battery?

On an 84 I believe the inertia switch is on the passenger side in the trunk, around the hinge somewhere. If you have trim panels in the trunk, there should be a hole in the panel to press down the white button on the switch. I know on 87-88's it's in the trunk, in front on the taillights, right near the latch.

D'oh! Nevermind, just looked at the post right above mine with the pic. Should've read all the posts before replying.
:)

fuel pump problems

Reply #8 – January 18, 2010, 12:43:17 PM

when i replace the negative battery cable i notice that the small black wire had so much corrosion that it crumbled. so i cut the section that was crumbled and put a little thicker piece of wire from the connector to the battery. since i replace the battery cable, the fuel pump haven't worked

fuel pump problems

Reply #9 – January 18, 2010, 02:08:16 PM

Quote from: blackcougar71;306788

when i replace the negative battery cable i notice that the small black wire had so much corrosion that it crumbled. so i cut the section that was crumbled and put a little thicker piece of wire from the connector to the battery. since i replace the battery cable, the fuel pump haven't worked

If what you did isn't working that will cause your problem.

fuel pump problems

Reply #10 – January 21, 2010, 03:27:38 PM

i fixed the ground that goes to the battery and pushed the switch in the trunk. nothing happened i still cant hear the fuel pumps. but i have notice some thing on the starter relay on the fender keeps on sparking everytime i try to start the car.

fuel pump problems

Reply #11 – January 21, 2010, 04:26:21 PM

Quote from: blackcougar71;307300

i fixed the ground that goes to the battery and pushed the switch in the trunk. nothing happened i still can hear the fuel pumps. but i have notice some thing on the starter relay on the fender keeps on sparking everytime i try to start the car.

?

You can hear the fuel pumps, or you can't hear the fuel pumps? Your first post says you can't and this last post says you can? Since you fixed the ground and pushed the inertia switch, do you have fuel going to the injectors now?

Check your connections and wiring at the starter relay, sparking is not good. I think there are a couple fusible links on the small wires running from the relay, check those too (I think bad links there would cause it not to crank, but check 'em anyway since you have some sparking going on there).

fuel pump problems

Reply #12 – January 22, 2010, 03:42:00 PM

sorry i cant hear the fuel pump still. i unplugged connectors at the fuel pumps and ran two wire from a battery to the pumps and they make noise and come on. but when connected back up to the cars wiring harness nothing. i also changed the fuel pump relay in the trunk to see it that would help but nothing changed. the part of the starter relay that is sparking is the side that runs to the starter itself opposite the side that the positive battery cable connects with all the fusible links.

fuel pump problems

Reply #13 – January 28, 2010, 12:20:19 AM

i figured out what was wrong the oxygen sensor were unplugs which cause the fuel pump not to turn on. after i made two special wire to make my oxygen sensor wires longer so they would be the right length to run down to my long tube headers. that fixed my problem.

fuel pump problems

Reply #14 – January 28, 2010, 12:57:28 AM

Quote from: blackcougar71;308172

i figured out what was wrong the oxygen sensor were unplugs which cause the fuel pump not to turn on. after i made two special wire to make my oxygen sensor wires longer so they would be the right length to run down to my long tube headers. that fixed my problem.

That doesn't make any sense.
The oxygen sensors have nothing to do with the fuel pump running.