Help Turbo Swap Problems

[stefjeff]

Help....I have a 1978 280z that I have put a 1981 280zx turbo engine in,  I have the 81 wire harness,ECU, Mass air flow and such.  Problem is I cant get  spark to coil or spark plugs.  When I turn engine over and have coil wire grounded to body it will spark 1 time and that's is it.  have new coil , another used igniter and the CAS that came with engine,  Used wire instructions from hybrid,,,bunblebee z I think , have power to fuel pump injectors just no spark, have green light on at ecu.  I am at a point to put 78 wire harness back in and just run it as a add on turbo engine or get a 82 distributor and shaft and swap.  any suggestions would be appreciated

Edited September 3, 2013 by stefjeff

[NewZed]

The one spark means that your coil works and is getting power.  The coil is supposed to spark when the ignitor breaks the coil primary circuit when the ECU tells it to when the CAS tells the ECU it's time.  The problem is in the CAS, ECU or ignitor.  You could easily have the same problem with an 82 distributor.

 

There are test procedures in the 81 Turbo Supplement or the 82 and 83 FSM, Engine Fuel chapters.  Takes some reading.  Seems to be a very common problem, you should be able to find many many threads on this forum about it.

[stefjeff]

ok  I will do some more research...have a feeling it may be the cas,,but there doesn't seem any easy way to test it,,so will try to find another and see what happens  I thank you for your help

[cgsheen]

Is the ECCS (engine) harness stock or has it been modified?  Specifically the wiring from the CAS, it's round 4-pin connector, or the 4-pin connector on the ECCS harness?  How exactly did you wire the Coil /Ignitor?  Are you using the stock turbo coil / ignitor?  Pics.

 

The coil / ignitor ("power transistor") has very simple wiring:  The standard Black/White from the ignition switch (+12V at IGN ON) runs to the ignitor and from there to the "+" side of the coil - giving power to both ignitor and coil at IGN ON.  Stock, there is a Yellow/White wire that runs from Pin 5 on the ECU directly to the ignitor (providing the "signal to fire").  The ignitor amplifies the signal from the ECU and causes the coil to fire - that's the Blue wire from the ignitor to the "-" terminal on the coil  (Tach also runs off this pulse, so the Blue wire also runs back to the tach through the tach resistor).  The Ignitor is grounded to the frame through the coil bracket (has to be grounded in order to work).  Verify that yours is all wired this way.

[Tony D]

Did the donor car you got the parts from run?

[stefjeff]

ok  that's for the help so far  I am not sure if the engine was working when I got it,, I I got the engine, turbo, all sensors and components from this engine.. have the yellow white wire running to ignitior and switch wire  to black white.  have black wire on ignitor connected to coil and other yellow wire run to switched also..per instructions.   I got   a little confused thou because I had 2 yellow and white stripe wires on my harness... found a used turbo ecu so will try when it get it..i do have a green light on my ecu...still will only spark one time...used all 81 turbo stuff from engine..unless I didn't run wires right from ignition harness.  I have afm plugged in but not bolted in...does it have to be grounded also..was wondering if car was a automatic from donor what about safety start switch ?don't see wire for one  may not matter  I have a 5 speed.  I did put a screwdriver to the pick up points on cas and could hear injectors clicking.  put test light on coil wire and it shows power.  when I turn engine over it will flash once.  test light show power on + and - side of coil. when I put test light on yellow white stripe wire from harness to ignitor it show a slight light ..but when i plug wire on ignitor it doesn't light the tester light up.....anyway  that's it so far  any help.....................and everything is stock with no modifications

Edited September 9, 2013 by stefjeff

[Tony D]

Get the FSM and a Multimeter before you post again.

 

You will not diagnose transistor gating signals with a test lite.

 

They are fine for a 62 VW with points, and interior lighting trouble. But on an 81? Sorry...you play you gotta pay. Sears or Harbor Freight DIGITAL multimeter with at least a 5, 12, or 20VDC selectable low range...