Fuel Pump Electrical Issue

[PC5505]

Okay, so my car wont start. Its a 91 AWD. I know what caused it, just not sure how to fix it. To start I'll give the order of events that led to this condition.

So my car failed emissions by a ton, I had 650cc injectors a 190lph pump and a rewire job by the previous owner. The ECU is chipped for the 650's and a 2g MAS(installed). Also the EGR was blocked off. I did all of the mods but the EGR and the rewire.

-My immediate problem is not the failed emissions test.

I knew I was running rich so in an effort to pass emissions the second time around I picked up an FPR(weaponR 1:1) and set it to 37.5psi(I have a 1G) which is as low as it would go. I unblocked the EGR and took it for another test. It failed again, but by quite a bit less. I figured I was on the right track, so the next day I swapped in the stock fuel pump. This is where my problems really started.

When I reinstalled the stock pump, and the car wouldn't start. The pumps positive wire somehow grounded on the bracket that holds the pump and blew a fuse. I pulled the pump, adjusted the wire and put it back in the car. Changed the inline fuse on the rewire from the battery and tried to start it. Still no start.

I pulled the pump out again and with alligator clips ran it to a spare battery I had in the garage to make sure it was running. I heard the motor spinning so I figure its good(was working when I swapped to the 190). Put the pump back in the car and plugged it into the harness without attaching the fuel line to it and had a friend try to start it. Nothing came out of the fuel line so I know its not pumping while its in the car. I don't know why.

There is a relay in the trunk that is part of the rewire with 4 prongs and a wire on each, I can hear the relay click like it should when the key is turned. I know they can still be bad even if they click, but I think its unlikely.

I don't know what else to check, electrical problems are not my specialty and I'm not familiar with how the guy routed the rewire, I know he added an inline fuel pump switch under the dash and it is in the on position.

Any help would be appreciated, I just sold my daily driver so it would be really nice to have this thing running while I look for a replacement.
Thanks

 

[tbonitz301]

Buy a new relay, and get that thing in the wind

 

[94sc61talon]

i would put a new relay in an then wire the pump urself just so you know its done proper

 

[PC5505]

I will start by replacing the relay in the trunk. A buddy of mine was saying he thought there was a relay or something under the dash that I might have fried; has anyone ever heard of this?

 

[1badtsiawd]

I would replace that relay or do a test on it.

there is a relay under the dash. It is called the mpi relay. This gives the pump power when you turn the car on. You might check the fuse for it, which is located on the battery terminal connection. also make sure a connection on your rewire did not come undone when you were swapping out the pumps.

 

[PC5505]

I plugged my logger in and tested the fuel pump in the test menu of mmcd and I can hear both relays click, the one in the dash and the one in the trunk. I'm having some trouble finding the relay to replace the one in the trunk, it should just be a radio shack thing right? I'll check that mpi fuse today when I get home. I thought I'd checked them all the first time I popped the inline fuse, but I'll go back and make sure. Thing is, would the rear relay click(get power) if the dash relay was having problems? For that matter the dash one wouldnt click if that fuse was out....

 

[Avionixx]

If the rear relay is clicking then the dash relay is working because that's where it gets its "ON" signal from. Have you checked for voltage at the pump harness while you switch the pump on from MMCD? Should be pretty darn easy to do on a 1G. Technically speaking, if that rear relay is working like intended and the rewire fuse has been replaced, that pump should power on.

 

[1badtsiawd]

the relay you need for the back where you did the rewire can be bought at any parts store. if you can't find one another way to go about it would be to take the relay out of the picture and just connect it back to the stock configuration. Then you will be able to narrow it down between the stock wiring system or the rewire that you did. after that you would be able to narrow it down a lot easier.