1992 nissan 240sx : no spark

[Tims_240]

f you're reading this i appreciate it, atleast someone is trying to help me.First thing i will say is that i took my engine out of my engine bay to have it rebuilt, however the funds didnt come as i expected over the winter, so i put back together the engine (got about to where i was going to start taking the cams out but never did, sooo i didnt get too far) and i painted my engine bay before i put it back in.now onto the real problem. I cannot seem to get any spark out of my igntion system whatsoever. EVERY ground that i can possibly think of, including multiple people that i know who own 240's, can possibly think of are connected. Yes i did say i painted the engine bay, but i sanded down the paint whenever i put a ground back on to ensure good grounds.

the main grounds i can think of off of the top of my head are:1. In the front left to where my old battery used to be, its the one that connects the intake manifold to the frame.2. the two grounds in the back right of the engine bay, one of them connects the Head of the engine to the firewall, and the other one peeps out of a wiring harness that connects to the Head of the engine also, they are side by side.3. there is a ground in the back right of the engine bay under that green thingy not sure what it does but it is connected (its right beside the plug-in for the BMC fluid level)4. there are each a ground directly behind the right and left headlights that come off of a wiring harness.5. there is a ground that connects near the left strut tower (a little below the strut tower bolts about halfway down the engine bay)6. there is a ground that comes out from under the fuse box on the front left side of the engine bay thats about 6 inches long that connects to the engine bay down below (cant see it by standing there)

now im sure i could think of some more if i went to my car and looked, but arent these the MAJOR ones, everytime i search on forums such as freshalloy and zilvia and nico, everyone that has a spark issue that posts, people tell them to check there grounds, well i have a bunch of times.

I have also checked every fuse one the car, i have not missed one i guarantee it! Now as i said before I am not getting any spark, so i should probably tell you what coil and such that i have.

I have a blaster 2 coil, i have the green and black wire going to the negative and the black and red going to the positive, that wiring is right, since i have searched numerous times trying to prove it wrong, everyone says the same thing for that. ok, so.. i have those two wires unplugged from the stock coil (obviously) but everything else is connected perfectly to the stock coil. there is a 3 wire plug, and a 1 wire slide on plug that are connected to the stock coil.

i have a multimeter, and am not too good with it but here is what i did.i got a good ground and then set the multimeter to volts, and put the positive on the positive side of the coil when the key is in the ON position. this gave me a reading of, i think 12.07, and the negative side was exactly the same 12.07, if it was not 12.07 it was extremely close.

Now i thought i should check the ECU to see if i had any codes, so i screwed it into diagnostic mode, and i got 2 readings.. 21 which is Ignition Signal Primary, and i got 12 which is Mass Air Flow Sensor. i have hooked up so many Z32 mafs to 240's for friends and such its ridiculous, so i am a pro at that, so i am not concerned about the mafs not being hooked up right, however the ignition signal primary has me worried.

-tim

[Tims_240]

i tried a new coil & power transistor, and that wasnt it, so far ive tried, a new ecu, new distributor, new coil & new power transistor, which basically means im screwed.my negative tested at -.17 volts, and my positive tested at 11.7 volts, going to my coil.-tim

[NISTECH]

check your resistor condensor connection. Smal block attached to the harness near the coil. also make sure your single black connector is attached to the coil.

[Tims_240]

i checked my resistor, and made sure all the wires were in, and i even replaced it with a buddy's. by single connector, im assuming you mean the slide on one, which is connected.

nistech, i know you are real smart about wiring and such, check this out.

http://putfile.com/pic.php?pic...=x402the "relay thing" is the resistor/condensor.does that look right? im almost 100% sure that that is the right way to wire the coil and such.

thanks,-tim

[rogoman]

Before you removed the motor, was the blaster coil installed and did the motor run OK? If not, try reinstalling the stock setup.

If your car is stock or slightly modified, there's absolutely no need to modify the stock ignition system. Nissan's OEM ignition system is excellent. Many folks that run turbos still use the OEM system with good results.

[NISTECH]

i checked my resistor, and made sure all the wires were in, and i even replaced it with a buddy's. by single connector, im assuming you mean the slide on one, which is connected.

nistech, i know you are real smart about wiring and such, check this out.

http://putfile.com/pic.php?pic...=x402the "relay thing" is the resistor/condensor.does that look right? im almost 100% sure that that is the right way to wire the coil and such.

thanks,-tim

Yea the slide one is what I was talking about.

I looked at your wiring diag, hard to make out whats going where as well as the wiring colors not matching the FSM. However I kinda deciphered it best I could and I wanna say it looks correct. One thing I gotta question is you have the white wire coming off the power transistor merging with another wire. It should be a seperate wire all the way to the ECM and that is the wire the ecm examines for a signal for the code 21. That is the ignition signal primary wire.

[Tims_240]

yea sorry for the bad drawing, but yes they do not go into the same wire they are all seperate, i just didnt want the drawing to be more confusing.

any other ideas you can think of?i have this huge book telling where every single wire in the whole entire car goes. including where the wiring harness's are and where the connect, throughout the whole entire car, also where all of the grounds are. so i have the information im just stumped.

another thing i thought of was when i switched the coil with my buddies, to see if mine was messed up, i never changed it out with his ecu, so maybe my coil and ecu were fried at the same time, not likely but maybe.

thanks alot man.-tim

[NISTECH]

if the book is the nissan factory service manual you can find the entire ignition wiring on page EF&EC-107 It has the diagram as well as the complete diag procedure for that code. You need to go after diagnosing that code as it is the source of the problem.

[NISTECH]

heres an image.

[Tims_240]

so if my wiring is correct, it has to be something going wrong with the ecu, distributor, resistor condensor, coil, or power transistor?because ive replaced all of them.im not really sure what to do next.

[NISTECH]

you probably have a connection issue going on. you need to start testing wiring. If you had a DSO you could test the crank angle signals, the ECM's firing signal and get a real picture of what is not happening.

[Tims_240]

how can i test to see if the distributor is telling the ecu to fire the coil?i would have to test wires that go from the dizzy to the ecu, and then if those work then test the wires going from the ecu to the coil. but which wires should i test, and how.-tim

[NISTECH]

The only real way to look at that signal with a DSO{oscilliscope}. No other way is at all reliable. first wire to test is the signal wire[white wire] between the transistor and the ECM. disconnect both ends and use an ohm meter to see if there is continuity.

[Tims_240]

nistech, thanks for your help dude. i finally figured it out, i was starting my car and my mafs plug must have been loose, and it got spark. so i took the plug out for some reason to see if somehow that could be it, and it was, i think my mafs wiring is a little messed up or something. but i got it working now.-tim