Car wont start, No power to fuel pumps all of a sudden

[Co-brat]

Ok I need some sugestions. I went to go drive my car today and when I get in to start it it just cranked and I noticed that the fuel pumps werent running. I have Lethals buget return setup and its all wired per their schematic. I drove the car about two weeks ago and it was running just perfect, I parked it where it sits now, didnt touch or do anything to it since and now I go out to start it two/three weeks later and now the pumps arent running at all. I started checking fuses under the dash and in the junction box under the hood and didnt find any blown but im also not sure about what ones I should be looking at exactly. Anyone ever have an issue like this? Any help or sugestions would be great. thanks.

 

[Cobra03SC]

You said the car cranked but the pumps arnt running? Thats not possible. Do you mean it just turned over and didnt start? Not sure exactly how that kit works, but i do have a kit from lethal also. Mine has a main wire from the battery to the trunk, there are also relays in the trunk for each pump with wire that go to each pump. I would trace all wires and make sure nothing is spliced, or a ground may have come loose. The relays may have gone bad, Also possibly check the button in the trunk. Also on mine there is a fuse under the hood, should be 12 inches or so from the main line connection, small and silver/clear. Check that one aswell.

 

[chappeja]

I'm not sure how your car started without your fuel pumps running, but if it's a fuse, then I would just google 03 cobra fuse box schematic...or something like that if you think it's a fuse...or just check every fuse. If it's a relay, I don't know how you would check that, other than listen for the contacts opening or closing.

 

[Co-brat]

The car does not start at all or even sputter, I have zero fuel pressure. It just turns over with the starter but does not fire.

yep I did all that already, even the inertia switch in the trunk and still nothing. for got to mention that I checked the trunk switch sorry. I have looked at the relays in the trunk and everything is still nice and tight, I have not gotten under the car yet to look at the wiring on top of the tank cause thats just going to have to be aproject for another day but ive checked evrything else I could think of so far. was looking thru some threads on a search and some people mentioned a CCRM problem but I dont know what that is or where/how to check it.

 

[chappeja]

Do you have someone to listen to the relays to hear if the contacts are shutting and opening?

 

[Cobra03SC]

The relays are like 5 bucks each, first thing i would do is replace the 2 just to be sure before i even went under the car to drop the tank. Its just weird that after you parked it they both dont work at the same time. Maybe take the power wire off the fuse box side and stick it on the battery itself and see if they come on. Or use a multimeter on the wires after the relays with the key in the on position and see if there is power going to the pumps with the key on.

 

[Neksnap]

No power at the pump...........Take out fuel pump relay. You can use a wire to jump across the terminals of the relay should be terminals 87 and 30. Have someone listen for the pumps to come on. if still nothing.....you can put 12v straight from battery to the 30 terminal in fuse box and see if that turns the pumps on...If still nothing.... than possible ground issue or closer to the pumps.... connectors or terminals on pump issue down to bad pump?

 

[Neksnap]

Also to me crank means motor turning........As in starter cranks motor....crank does not mean start so OP is correct in term.

 

[chappeja]

I hate electrical issues...gotta be worse than even trying to diagnose a mechanical motor issue.

 

[Co-brat]

thanks for the the help and sugestions so far fellas. I starteddo ing things the logical way and busted out the old handy yet simple test light and I have found something interesting. The large 40amp fuse which connects the 8 guage power wire from the engine compartment junction box to the relays in the trunk was blown. I thought I had solved the issue right there, thought it may have been a freak occurence...WRONG! So i put a new 40 amp fuse in, turned the key to the run position where my pumps should turn on and POP! I followed the large 8 gauge power wire from start to finish and found no issues. So I have concluded the there is a power wire that has either rubbed through or come loose somewhere near the tank around the pumps and must be grounding out on the chassis. So now I gotta drop the damn tank and look around under there.

Original 40 amp fuse that was given with Lethals return kit:

The second 40 amp fuse which popped almost instantly:

 

[jetmech]

You have a wire that is grounding out

 

[Mystic03]

You have a wire that is grounding out

+1 finding those problems are a PITA!