# 1987 Multi - Code 21



## autodoc2000 (Nov 29, 2004)

My 1987 Nissan Multi 2.0 L (CA20E) front wheel drive standard trans quit running like the key was turned off and it wouldn't restart. I've had this car for only a short time and haven't had the time to give it the once over. 

During preliminary inspection for the subsequent no-start, I discovered, under the distributor cap boot, the exhaust coil wire terminal on the distributor cap had been cracked (looks like a sharp blow at one time). The crack had corroded with grey dust to the point that the wire fell from the cap. I replaced the distributor cap, rotor, ignition wires and spark plugs. The car fired up and ran for ten minutes or so in the driveway where it subsequently quit again. After that, the engine may crank and crank with no start at all or it may fire right up and run for a few seconds to two or three minutes (give or take) but it always dies like the key is turned off.

I have extracted a hard code 21 identified in my diagnostic info as no ignition signal. I am wondering if anyone has the trouble tree or any other info that may help me narrow the problem down. The diagnostic info I have is sketchy.

I've done pinouts at the ECU, appropriate voltage checks, voltage drops and resistance measurements according to Mitchell and Alldata. The only erroneous readings I seem to get are at pins 5 and 14 at the ECU where my logic probe is supposed to pulse and it doesn't; it only glows. (I'm checking this while engine cranking, not running. I don't know if this is the correct way or not).

My question would be, what circuitry or components does code 21 involve?
Thanks for your time.


----------



## KA24Tech (Feb 2, 2004)

It may make a difference if you have the 8 plug or 4 plug but the distributor contains the crank angle sensor. I would check the input to that.

Troy


----------



## autodoc2000 (Nov 29, 2004)

*Nissan Multi - Code 21*



KA24Tech said:


> It may make a difference if you have the 8 plug or 4 plug but the distributor contains the crank angle sensor. I would check the input to that.
> 
> Troy



You nailed it, Troy. 

I borrowed an automotive digital oscilloscope and checked for reference from the distributor to the ECU on #8 terminal at the ECU (green/yellow tracer). Sure enough, when the engine would fire while cranking I had a waveform and when it wouldn't fire while cranking, the scope pattern was flatlined. Looks like distributor time!!

Thanks for the info. Great forum !!! Glad to be on board. Hope to return the favor sometime.

Randy.


----------

