ECU getting no power & 2 unidentified plugs

[jdm_dean]

I have a 91 240sx with a sohc from a 89. problem is the car isnt getting spark & the egi pump relay is clicking nonstop with the key in the on position. can't find any loose grounds though..ideas?

and the two plugs at the bottom of this picture i cant identify or find a connector to match. im more concerned with the wide white one thats coming off the ecu harness. can anyone tell me what this is or what its for?

car would start up and then die within like 30 seconds. compression test is good, its getting gas because the pump primes and the plugs smell of gas. just no spark, and now the ecu doesnt even blink when i try to put it in diagnostic mode or when you switch the key over. :ugh:

http://sphotos.ak.fbcdn.net/hphotos-ak-sjc1/hs318.snc3/28555_1425393671691_1138252450_31236489_7240624_n. jpg

[jdm_dean]

just figured out what the smaller plug is. light for the kick panel. just need to know wth the wide white plug is for, maybe thats a part of my problem?

[g6civcx]

The white plug looks like the F1 plug that gives the ECU signals from things like start signal, VSS, CONSULT, etc.

I hope you're using an SOCH engine harness with the ECU plug and SOHC ECU. Otherwise it will be harder to troubleshoot.

I'm too tired to look up for you but that's what it looks like. Maybe tomorrow.

[jdm_dean]

weird part is, the ecu was getting power 2 days ago.

im stumped...the harness and ecu is for an sohc. complete swap.

[VNG704]

I have a 91 240sx with a sohc from a 89. problem is the car isnt getting spark & the egi pump relay is clicking nonstop with the key in the on position. can't find any loose grounds though..ideas?

and the two plugs at the bottom of this picture i cant identify or find a connector to match. im more concerned with the wide white one thats coming off the ecu harness. can anyone tell me what this is or what its for?

car would start up and then die within like 30 seconds. compression test is good, its getting gas because the pump primes and the plugs smell of gas. just no spark, and now the ecu doesnt even blink when i try to put it in diagnostic mode or when you switch the key over. :ugh:

http://sphotos.ak.fbcdn.net/hphotos-ak-sjc1/hs318.snc3/28555_1425393671691_1138252450_31236489_7240624_n. jpg
wait, I thought the ecu turns on the fp.

if the ecu isn't getting power then there may be a short somewhere between the ignition and the ecu(considering the ignition switch and ecu are good). Do you know how to use a Digital MultiMeter? There is a thread here somewhere if you search. Ecu was getting power 2 days ago, shorts happen, so that may be the culprit. Check your fuses or relays yet?

Get an FSM to find out what that plug is. It would also have a wiring diagram to help find the short if there is one. It also has troubleshooting steps to follow for things like, no spark.

[jdm_dean]

wait, I thought the ecu turns on the fp.

if the ecu isn't getting power then there may be a short somewhere between the ignition and the ecu(considering the ignition switch and ecu are good). Do you know how to use a Digital MultiMeter? There is a thread here somewhere if you search. Ecu was getting power 2 days ago, shorts happen, so that may be the culprit. Check your fuses or relays yet?

Get an FSM to find out what that plug is. It would also have a wiring diagram to help find the short if there is one. It also has troubleshooting steps to follow for things like, no spark.

It's not priming now but before it was. Just had no spark. Now I'm not gettubg anything. because the ecu isn't working. I just bought a DMM yesterday, I know how to use it. When you say FSM do tou mean like a chilton or haynes?

[jdm_dean]

Oh yeah, all my relays and fusible links are good. Like every single one. The bracket that the ecu mounts to, is that its ground possibly or solely for mounting it.

[jdm_dean]

answered my own question, ecu is getting power. pin 104 on the ecu isnt getting battery voltage like it should so my relay is clicking on and off rapidly. :\ short??

[jdm_dean]

bump..........

[VNG704]

yahoo search "FSM sr20det or 240sx" nico dot com has some links to nissan fsms. They are free to download. Not sure if haynes or chilton has wire diagrams as I've never owned one from them. I actually bought mine on a burned cd by someonen making mass copies and selling ebay...back in the day when I didn't know they were free online.

my scenario: car died on me. wouldn't restart. fp wouldn't prime. fuses and relays were okay. ecu is good(but didn't power on), ignition switch tested good. Did a search and alot of replies of "jump clutch interlock relay" I did that, it finally cranked but did not catch because fp still did not prime. I did some wire tracing with dmm, it turned out the be ignition kill switch (installed by p.o.) wiring burned or shorted. ...basically, a short in wiring between ignition and where ever it goes to from there. ecu doesn't turn on until the ignition tells it to. That is what I think your problem is. A short. The fsm will help you trace it down. they have wire diagrams. sorry for the poor grammer and good luck.