95 240sx - No spark, no fuel....

[flackjacket]

Hey guys, just seeing if anyone had some help in diagnosing an issue I have with my 95 240sx.

Engine: 2.4L KA24DE

I am getting no spark. The spark plugs don't have any fuel on them, nor do they even smell like gas. The fuel lines are pressurized and the pump is turning on.

I checked the ECM (ECU) and it gave me a 55 ( ALL CLEAR) code. So it seems like the computer is working. I think it may be that the ignition coil may be at fault. But I am not sure if there is an ignition signal that gets sent to pulse the injectors and thats why I am not getting fuel into the chamber?

Anyone familiar with this? Would a bad distributor/coil be the cause of this? The coil is also built into the distributor with 3 seperate plugs going into it....

Thanks!
Dan

[WhatsADSM]

How do you know you aren't getting spark? At least put a light on the wires to make sure it isn't firing.

Also check to make sure you have switched 12v at the coil(s) and the injectors.

[flackjacket]

I took out a plug (tried #1 & #2) grounded it and turned it over.

I checked the coil and it did have 12v switched coming in.

[juicedimpss]

I took out a plug (tried #1 & #2) grounded it and turned it over.

I checked the coil and it did have 12v switched coming in.

what about the injectors?

[flackjacket]

Injectors are not clicking. They do not seem to be getting pulsed.

[WhatsADSM]

Are you getting constant 12v to one side of the injectors?

[flackjacket]

I'll check that out tonight. I don't know why but I was thinking that the injectors get pulsed with 12v+. But they must run on 12v constant then get hit 12v- when they open?

So when the car is sitting with key on, I should be getting a 12v reading... correct?

[WhatsADSM]

An injector in an EFI setup works as follows (I am simplifying a little):

One side of all the injectors sits at a constant +12V. The other pin is floating, and when the ECU wants to fire that injector it grounds (0v) the floating pin. Hence you have +12v on one side 0v on the other, current flows from the constant 12v through the injector to the ground. This current through the injector creates a magnetic field that drops the pintle down (moves the discs, moves the balls, etc depending on the mechanics of injector).

Yup with the key in the on position you if you remove the injector connector and probe it one of the pins should be +12v the other will be floating.

[flackjacket]

good stuff, I have softball in shorewood until 8 so I'll get to checking it after that. Thanks. :)

[flackjacket]

Ok, so the Injectors are getting 12v switched. Sorry it took me a while.

[flackjacket]

I would assume at this point it would be either a bad ECU or perhaps a bad distributor. If, lets say the CAS is bad, then Injector pulse wouldn't be sent out either right?

[Flicktitty]

i would be willing to bet it's a bad ecu....

get someone with a ecu and try it.

i got a ecu out of a 93 auto

[WhatsADSM]

Sorry didn't see the update to the thread.

Yea it honestly could be any of the things you listed.. Bad CAS, distributor/coil, or ECU. My next step would probably be to see what kind of signal you are getting at the injectors. If you are infact getting fuel (via injector pulse) and not spark, then you have a good CAS, and (likely) a good ECU, and it would probably be a bad distributor/coil.
If you don't have any signal at the injectors to fire then it is either a CAS or ECU.

I honestly forget since it has been a while since I have seen a KA, but does it have an external coil or is it built into the distributor?

[flackjacket]

Coil is built into the distributor.

I'll drive up to the shop tomorrow and run some more tests.

[WhatsADSM]

Cool keep us posted.

If it comes down to it, I have a scope we can put on there to check the signals at the distributor and injectors if need be.

[flackjacket]

Ok, i think i might be onto something. I took out an alarm system when I first got the car.....because it wouldn't start. But looking at this diagram makes me wonder if that may have something to do with what is going on.
http://www.flackjacketcreative.com/uploads/Picture%2038.png
http://www.flackjacketcreative.com/uploads/Picture%2039.png

I am going to borrow a Diagnostic machine tomorrow and hopefully figure this out.

[flackjacket]

Well I got the car running tonight. It was a bad relay. The ECCS relay behind the ecu was faulty. I put in a new (used) one and it fired right up. Now I can take the motor out and put in the SR20. lol.

Thanks for all the help guys (WhatsADSM)!

[WhatsADSM]

Congrats and GL with the SR20 swap!