so problems..... i went to start the car and she turns over no problem but wont start, upon further inspection i dont think shes getting fuel or spark. I pulled the plug and checked for spark, nothing, no spark. And im not really sure at all how to diagnose the system because of the electronic distribution and what not, ive only ever worked on cars with dizzys and the FSM was incredibly not useful in troubleshooting.

Also i looped the f/p gnd plugs in the diagnostic plugs to check the fuel pump and it sounds good and there sounds like fuel is running through the lines, I didnt have a fuel pressure tester so im not sure if the problem is its just not pressurizing or what.

Also when looping those plugs to see if the fuel pump is working shouldnt it shut off after a few seconds once pressure is built up? cause it didnt shut off it kept going for as long as i had the key in the on position.

regardless of fuel pressure i also dont think the injectors are firing. i listened to see if they were clicking when turning the car over and i couldnt hear anything. My friend and i were thinking this might be because the ecu isnt grounded properly?

Also another quick question, i have a jdm engine, harness, and ecu and when i went to plug it all up everything plugged up correctly except for the blue plug that that looks like it come off the engine harness and plugs up to the interior harness, on the jdm harness it has an extra row of plugs off the side that the usdm does not have. The wiring diagrams i have are usdm so they werent much help, does anyone know what those two extra wires are for and what to do with them? I managed to get the plugs connected by just clipping off one side of the female connector (probably a dumb idea, but i was pissed at the time) but theres still the problem of the two open wires.

Thanks in advance for any help guys.

 

ok that blue plugs give power to injectors and spark. Search around, there was a thread few weeks back, you have to repin that blue plug and the extra wire coming that's not used on that blue plug must be connected to the empty slot in the x14 harness so that you won't get a CEL for the fuel temp.

 

https://www.rx7club.com/3rd-generation-specific-1993-2002-16/jdm-wiring-harness-spec-868289/


topic been discussed a million times.

 

sweeet, thanks alot man.

it didnt even occur to me to search for the plug being the problem.

 

soo...i rewired the pins, according to that writeup ^ and still nothing, i double and triple checked my wiring on that pin and its definitely correct but im still having the same problems, getting neither fuel nor fire. me and my buddy are suspecting either a bad ECU or bad wiring harness, anyone know how i can tell if its a faulty ECU? Or does anyone have any other ideas?

thanks in advance

 

as far as i know, which is admittedly not much compared to most on the forum you cannot test if you have a bad ecu, you can only swap in a known good one and see if that works for you. In any case ground the bastard and double check everything. If you still have no luck ive got a spare 8-bit jdm ecu you can have for a flat $35. Also check the coils I dont know the mileage on them, but there is a slight possibility they could be gone, the FSM is pretty clear on how to do that. I believe you can always rent a tool from O'Rilley or Kragen, and probably a few of the other chain auto stores around, usually its just a couple of bucks a day thats an easy way to get a fuel pressure gauge w/ everything you need if you dont feel like fabbing one yourself.

 

Check the fuse box thats attached to the battery termenal,....wigggle it around, tap it and such, see if it starts. its not the fuses but whats under them....

Under the fuses are copper waffer like fins that corrode over time, allowing the car to crank but not turn over. The fuse box can be taken apart to be cleaned also, but id recomend just buying a new one, there not that expensive ( if it is the problem)

 

Does the tach bounce slightly while cranking, very very slightly?

 

it does bounce, but i would say it bounces more then just slightly



and thanks for the info ill check the coils and that fusebox to see if thats the problem

 

you sure you got the wiring right? show us what you did exactly. Also is your egi fuse still good? I got a jdm ecu if you want :-D

 

I followed the procedure according to this thread: https://www.rx7club.com/showthread.php?t=868289

in a short summary i repinned the blue plug to match the usdm plug.

X-05 USDM (EM)10 PIN CONNECTOR

|B/L|BR/B| XXXXX | Y | B/G |
|BR | R |B/W|W/L | B/Y |BR\W|

took this: and made it into that ^^
X-05 JDM (EM)12 PIN CONNECTOR

| B/L |BR/B | Y | XXXXXXXXXXX| B/G | W/L |
|BR | R | B/W | BR\Y | B/Y | XXX |BR/W|

i may have pinned it wrong, but i know my wiring was good
Also when i wired it the first time i suspected i may have wired it backwards so i reversed it, but once i did that when i reconnected the battery the fans came on with no key in the car, then when i turned the key on the fans shut off so i figured that was the backwards one.

Thanks for all the help guys!

P.S. i did find a guy with a good ECU in the area who will let me try it out, BUT not untill after the holidays

 

update:

im unsure if this is a related problem, but when i turn the car on all the dash electrical works except for the stereo... i did a quick check of the fuses and they looked fine, but i wanna see if this could be related to my other problem?