Trevor Deisher

Hello everyone this is my first Nissan car. I have been working on it bought it not running but knew it would not spark. I have changed coil and upgraded the power transistor to the PWR-2 but still no spark. I have power leading to the coil it reads around 11 volts and the coil is new and test fine. but i can not get any power to come from the coil to the wire all connections seem to be good but the people that had it before me spliced and re tied a lot of wires. Does anyone know what voltage should the plug put out to the coil and what could cause it to spark even if coil and wire check out to be good?

rogerz

12 volt. Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen. Usually on a rainy night around Oh Dark Thirty.

cas signal not getting to ecu. check the spark and coil the old way. hook twelve to coil primary. attach a gounded plug to the primary with a spark wire. be sure coil secondary is gounded. take a twelve volt wire and hit the secondary momentarily if you do not generate a spark the coil is toast.

if you understand a make/break points spark system this one is the same only the power transistor takes the place of the points. transistor controlled by cas signal to ecu. how do you know the transistor you used is good?

Trevor Deisher

Thanks I will try that but i figured signal was getting to ecu since has voltage going to plug for coil

turbotim

I have know idea what im talking about. But remember, these cars won't start if someone takes out the distributer and does not put in back in perfectly on the right tooth. It will leave ya running in circles for a while.

Trevor Deisher

I have thought about distributor not being lined up correctly but that would not stop coil not creating spark

Trevor Deisher

I check the resistance in the transistor and in coil as the book says and the chiltons

rogerz

you don't understand what make/break spark systems do. when the secondary magnetic field collapses it jolts the primary thus inducing high voltage which goes to the spark plug. there is always volts to the secondary thru the transistor. the ecu then interrupts the circuit just as points did in older cars. this causes the secondary field collapse which causes the primary to spark.

here is a way to test a transistor. I wouldn't trust chilton to know the difference between NPN or a FET. beware this test will not detect a marginal transistor that might fail due to high heat.

http://www.electronics-radio.com/art...istor-test.php

check the position of the rotor when the #1 cyl is TDC. should be pointing at or around #! spark plug wire. be sure transistor and coil are securely grounded. full 12 volts and secure gounds are necessary. the z31 electronics don't work well at lowered voltages. If you are grounding the battery thru the bell housing this is a marginal connection and can defeat you

Get your battery load tested. Be sure you have clean, tight corrosion free terminals on both ends of your battery cables. Be sure the ground (negative) cable goes to a bolt into the frame before going to the starter. grounding through the starter is not a reliable connection. Z's don't like low voltage. causes the electronics to act funny. it is possible to have enough amps to crank but not enough voltage to run the electronics. If you have one size fit all cheapo clamp on terminals they are a problem waiting to happen. Usually on a rainy night around Oh Dark Thirty.

Trevor Deisher

Thanks I have to rewire they guy that had before me done a horrible job they spliced every wire and have just electrical tape covering them found thisbafter further inspection

rogerz

yeah I don't know what people like that are thinking. get a solder gun and some good electronic duty solder. heat shrink and a heat gun to finish the work. I've got two alligator clips mounted on a piece of plywood. they will hold the wires in place to solder. slip the heat shrink on first!!!

Trevor Deisher

I got the stuff but the board with clips is a good idea would make it easier they messed up a lot of wires hate doing electrical