[scott351w]

I just recently pulled my car out of the garage, onto a sloap rearend on the down side. Had about 1/8 tank of fuel maybe less and when I started it, it made a few clunk sounds then ran with iradical idle then continued to idle normaly after about a minute or two. Then I shut it off and then the next day went out to start it. When I turned the key the pump would come on for about half a second then shut off and I could hear the fuel pump relay, it would click twice pause then repeat over and over until i turned off the key, the engine will crank over though. Next I pushed it out onto the road on level ground added about 3 gallons of fuel to see if maybe the issue was the pump from sitting out of the fuel for the 2 months in the garage also put a new relay in. Still did not fix the problem. So I sprayed starter fluid in the throttle body and it fires up when I crank it also checked the fuel pressure on the lines and there is zero. And I Jumped the fuel pump relay and the pump would come on full power and then slow down to a low hum so it may still have a few miles on it. Next I checked the inertia switch and it is reciving a small voltage 1.7 vdc on the computer side and 11.8 vdc on the pump side. Still cant find any problems on the starting circuit or EEC circuit or the FP circuit, So I am leaning towards either cloged filter or pump screen and or weak pump. Any words of wisdom on this matter would be much apriciated, Thanks.

 

[David.kinter]

So let me get this straight... that is one wall of text btw... you've checked the voltage coming out of the relay under the drivers seat going to the pump and it reads good. You hear the pump prime but fuel pressure is crap. It sounds to me like the last sentence of your wall of text holds the answer. Badly clogged filter or weak pump.

 

[89coupe]

If you have 1.7v on one side of the inertia switch and 12v on the other. Your light bulb should go off. Try removing the connector for the inertia switch and installing a jumper on the connecter. See what she does then.

 

[David.kinter]

If it was the inertia switch wouldn't the pump not come on at all?

 

[scott351w]

Sorry for the wall of bla =P, just trying to put as much detail in that I can. Update I just put a new filter in and checked the old one was a bit clogged but it still didnt fix the problem. As for jumping the inertia switch shouldnt I have 12v on one wire and no power on the other wire ? cause one wire should have 12v then enter the inertia switch and go back down the other wire to the pump correct ?, I'm just trying to rule out bad EEC, Pump at all costs. Oh I found out what the clunk was when I started it, My exhaust pipe coming out of the cat going to the muffler split in half and fell down =\.

 

[scott351w]

Well just put the new fuel pump in and still does the same thing. so I'm leaning towards a computer or the eec relay but I cant seem to find it I know it is near the computer on the passenger side kick panel but I cant find it in there. I just hate tossing money into it even though I had planned to put a higher flow pump in just not yet I wanted to replace entire fuel system but didnt have enough diaper money saved up. What do you all think I'm about to loose my mind on this, I miss my carbed 82 stang... damn fuel injection is for the birds lol?

 

[ghost5486]

Well just put the new fuel pump in and still does the same thing. so I'm leaning towards a computer or the eec relay but I cant seem to find it I know it is near the computer on the passenger side kick panel but I cant find it in there. I just hate tossing money into it even though I had planned to put a higher flow pump in just not yet I wanted to replace entire fuel system but didnt have enough diaper money saved up. What do you all think I'm about to loose my mind on this, I miss my carbed 82 stang... damn fuel injection is for the birds lol?

The inertia switch should have 12v on both sides key on, i just spent 2 weeks with a similar problem. I would start by finding out why one side has 1.7v. Some electrical diagrams would help if you don't have any.

Mustang FAQ - Wiring & Engine Info

 

[scott351w]

Well I thought I had fixed it with a ECC Power relay and now it is clicking at the relay again. I just took the computer out to inspect it for bad internal connections but it looks like new. Not sure where to go from here lol I just re-registered the car too.. is there anywhere to go to have the computer benchtested so I dont waste anymore money on this repair ?

 

[scott351w]

I think I found the problem i'm not getting 12v on the pink/black wire on the fuel pump relay, but I get 12v on all other wires going to the relay. I checked the ground that comes out of the wire harness near the hatch light and it seems fine. Not sure why its not powering the pink wire.