Fuel delivery problem - '89 Pathfinder

[Guest 94vtecmn]

Ok, here's the story. Started the car the other day, ran for about 5 seconds and died, as if I turned the key off. After checking a few things, the fuel pump fuse is blown. Only having a 20amp fuse left, (Fuel pump is a 10amp, I know, mistake) I stick that in there, and it fires right back up! Runs for about 30 seconds, and dies. This time, no blown fuse. Oooops.

 

So I start with the obvious, fuel pump. Get that out, test it, and it spins just fine on 12v. Check the wire harness for current, no current coming to the fuel pump pin. There is power there for the low fuel and fuel gauge, and they seem to be working fine. So I hot wire the fuel pump with a lead directly from the battery with a 10amp fuse, fuel pump spins just fine! Put the key in, turn it over, doesn't fire a lick. So to make sure I got spark, I pour a little bit of gas down the intake, fires right up for about 2 seconds, and dies, as expected.

 

So, I have spark, the fuel pump is running, but it won't start on its own. Now, what I believe is there is a return signal needed for something from the fuel pump, and thats not happening. My hot wire job consists of grounding the black lead of the fuel pump housing, and the 12v goes directly to the Blue wire. There is a White wire coming out of the fuel pump housing, that inside is a black wire. Do I need to give that a 12v current, similar to a power antenna lead from a car stereo to turn on the fuel injectors or something? If so, where does that need to go? Am I on the right path of patching this thing together?

 

Any help and suggestions greatly appreciated. This is my winter beater and I don't plan on spending anything if I can cheat it back to running condition.

[94extreme]

try running the ECU codes.. i am having very similar symptoms on one of my another vehicles.. let us know if you figure it out..

[Guest 94vtecmn]

I don't have a check engine light, and I don't know how to run the codes. Its as if there needs to be a signal to something saying "I'm the fuel pump, and I'm working, so fire the fuel into the motor" that isn't happening......

[GrimGreg]

Hows the fuel filter? Have you tested the injectors?

[Guest 94vtecmn]

Haven't checked either of those things. Would a clogged fuel filter prevent it from running all together, AND blow the fuse? With a good fuse in there now, it doesn't blow the fuse, but it doesn't run either. It ran for 30 seconds after it quit the second time, without blowing the 20amp fuse that should have been a 10 amp

 

How would I test the injectors?

[94extreme]

ecu codes procedures are a sticky in the garage i think.. there also may be a thread about the injectors..

[k9sar]

My first thought would be fuel filter but that shouldn't blow a fuse

[Guest 94vtecmn]

Well, after reading Adrians issues, it sounds similar, except I put in too big of a fuse, which probably blew something else, and now I just need to bypass that, or determine what it is and replace it.

 

Wiring issues, what a pain......If I knew where the wire that comes back from the sending unit in the fuel pump goes, I could probably fool it into thinking its ok. That may be what ultimately blew, the sending unit in the fuel pump assembly. I mean the fuel pump itself seems to work like a charm. Its just not sending the signal on to the next stupid sensor to say "Carry on"......