Help, no start on a SR

[-=RS13=-]

Ok something is fubar'd on my car.

I was driving, stopped at a restaurant and about 1 hour later my car did not start. I did not hear the fuel pump so i change it in the parking lot.

Still no fuel pump so i tow it back to my house.

Here is what i found.
25A Engine Control Fuse was blowen (in underhood fuse box intake side)
My fuel pump is not turning on.

So i hard wire the pump directly to the battery and it works fine.

But it did still not start.

I have not checked spark yet, CAS or injector pulse, but i have swapped relay's and fuses with my buddy and the same thing happens, Nothing.

I have a S13 with an SR with a walboro, FMIC, T25, Mines ECU.

I am thinking ECU but i am not sure.

Any ideas, this is my daily driver so i need to soon

[g6civcx]

Is the starter cranking?

[mjjstang]

are you sure you havent blown your friends fuses in your car, usually when a fuse blows, its going to keep blowing until you fix the problem, the only thing you fixed was the fuel pump, but this is the Engine control fuse, so there might be a short somewehre besides the fuel pump. Ecu is where my money is.

[-=RS13=-]

It cranks but it just keeps cranking with out catching.

I am sure i did not fry my buddies fuse and it worked on his car after.

the Fuel pump is not fixed.

Even with it hardwired to the battery the car is not starting. But you can definatly hear fuel bypassing the regulator with it hardwired.

My swap has been running for about 1 year, and i went through my whole harness before to make sure there was not a short.

I am pretty sure on the ECU. I have power to the fuel guage at the back but nothing to the pump unless i bypass the ecu, relay and fuse.

[Maeda]

So... is the pump busted or is it wiring related?

Have you tried swapping the relay?

[-=RS13=-]

when the pump is hooked up straight to the battery and the ground it pumps. I have also swapped relay's. It is the big relay under the hood labeled EGI pump right??

I am still soooo confused

[mjjstang]

yes, there is a relay called EGI pump, and the fuel pump fuse, both in the same box, that controll the fuel pump.

[g6civcx]

You need fuel, spark, and compression. Just because your fuel pump is priming doesn't mean it's pumping enough pressure. You need to check fuel pressure.

Then are you getting spark? Maybe your ECU is fubar and not delivering spark.

Then you'd start looking at timing and compression, etc.

[slider2828]

Yup had the same problem. Sometimes if the Engine Control Fuse is blown and you change it, you might get it to crank. In Nissan motors or wiring, everything is linked to the ecu, therefore, fuel pump, spark and other electricals are linked directly to the ecu. Swap out the ecu and try again, if it works, your ecu is blown. Unlikely relays are busted from the sounds of it.

[-=RS13=-]

Yup had the same problem. Sometimes if the Engine Control Fuse is blown and you change it, you might get it to crank. In Nissan motors or wiring, everything is linked to the ecu, therefore, fuel pump, spark and other electricals are linked directly to the ecu. Swap out the ecu and try again, if it works, your ecu is blown. Unlikely relays are busted from the sounds of it.

It was cranking with the fuse gone. I wish changing ECU's was that simple. There are about 10 people in my city with SR's, 4 have redtop's and 2 of them are running power FC's.

What are the chances of popping in a new ECU and having that blow from a short in the wiring somewhere.

I have CAS signal and fuel pressure (if pump is shorted to battery).

Tomorrow i am going to test my ECU.
Someone correct me if i am wrong but according to the ecu pin out.
34 should have power when i crank (12V)
36 should have power when ignition is in run position
38/47 should have power comming out when ignition is on
4 should have power comming out when ignition on (fuel pump relay)
6/13/39/48 should be grounded.

anything else that i should test for???
http://img97.imageshack.us/img97/9638/ecudiag3cz.gif (http://imageshack.us)

[g6civcx]

Check all your grounds. Check your fusible links. They look like big fuses. Sometimes they'll blow.

It's entirely possible that the ECU is blown. Electronics are very fragile. A huge voltage spike may fry the whole thing.

I would try to figure out why the fuse is blowing. My money is a bad ground somewhere. Don't try to start it until you can get the fuse to the fuel pump to not blow. That's not good.

I would check fuses, check ground, and look over wiring first.

[-=RS13=-]

I have replaced all of the fuses and they are not blowing anymore. They are all good but it is still not cranking.

Oh well looks like ECU

[TibDrifter]

to comfirm that it is the ecu than first check for RPM signal THan Fuel injector with a noid light of just listen to it with a screw driver and your spark if that is ok most likely its not the ecu but its in your circuit that you blew your fuse on, chaging fuse doest get rid of the problem find ou why your fuse blew, most likely a short to ground. Good luck