Preserved from CalaisTurbo. Original authors and dates are shown; archived members are not current Holdcom accounts.
i just found this info while browsing the net.
NO SPARK VL COMMODORES
System uses an LED crank angle sensor (CAS) within the distributor to generate a speed signal (360-degree for timing) and a position signal (120-degree signal) for the computer (ECU). The ECU then uses these 2 signals to generate a trigger to the power transistor (PT) bolted to the outside of the distributor. The PT uses this trigger to switch the -ve coil to ground to generate spark.
On top of the distributor is a 4 pin harness plug - this is the crank angle sensor. With this plug removed test the voltage on each pin of the female harness plug against ground (engine earth/battery -ve) with the ignition on (KOEO).
Should have 12v (battery volts from the EFI relay), earth (Ov), and on the remaining 2 pins - 5v on each (from ECU).
Ensure the distributor shaft is turning during cranking - cam belt.
With the engine cranking these 2 wires which had 5v on each are the important signals you are after - expect approx. 2.3v on one and 0.3v on the other. If the CAS has failed expect close to 5v OR close to 0.0v on one or both. If the signals are BOTH within 20% of specs., then
Check the signal from the ECU to the PT (fawn wire onto PT). If ECU is generating the correct signal expect approx. 0.4v. If a greater voltage, then you have an earth problem. If 0.0v then the ECU is not outputting the signal - ECU failed. If correct signal but still no spark then the PT has failed to switch the coil (rare) or the coil has failed (common).
To check the PT is switching the coil, use a normal test light from the +ve battery to the -ve coil (brown/red at PT). Your light should illuminate with KOF (ignition key off), and when the coil is switched to ground through the PT during cranking. If your test light flashes during cranking then PT is doing its job so coil has failed. If no flashing then PT has failed. Or if test light constantly lit, then PT has failed.
ROUGH IDLE VL COMMODORES
A common problem with the 3-litre Nissan engine is where the idle deteriorates to the point where it will not even run. Before that happens there is an initial loss of power, which just gets worse. A prime cause of this is the Air Mass Meter drifting beyond specifications - check the load pin (3rd in from back of engine - white wire) against an earth should have KOEO no less than 1.26v (excessive lean) and no more 1.32v (rich). If this load setting base is out, you won't be able to adjust the idle mixture (1st pin in from front of AMM) factory lean at 3.6v to richer say 2.0v to a satisfactory mixture - AMM will need replacing.
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there is a rule saying i cannot sticky my own thread lol
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sounds like wat mite be the prob wiv my car
thanks guys good find
Some original photos have not been recovered yet.
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yeah ive done 2 cas, and 1 afm. pain in the arse!
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hey im ahvin the no spark problem at the moment i have pulled the cas put of a dizzy that wasnt in very good nick can i test it with out goin 2 da trouble of puttin it in n finding out it dnt work thanks
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I was under the understanding that the higher the voltage between the number 1 pin and earth when you were moving the idle setting the richer ie 3.36 to 3.38 was a move to make the car richer ? It has always seemed to be correct when I have been fiddling with the afms that I have touched ? What is the go ?
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somebody please help!ive just swapped in an rb30et, and have no spark.it has new plugs, leads,cap,rotor button,have tried 2 coils, one which definately works,3 cas all proven to work,2 different power transistors,and it has voltage at the coil,and correct voltages at the cas with the key on.also tried 2 ecus, one which was working perfectly when removed 2 days ago, one working perfectly a few months ago.any suggestions?please?
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12-05-07, 14:28 GMT+10#10 I had a Formula VLT which I sold last year which was runnin 12.3sec 1/4 miles with stock ECU and one extra injector controlled by microfueller. My tuner told me the settings for the AFM which I used to always stick to and it was perfect. Here are the settings;
Pins 2 & 6 (Ignition on but engine off) - 3.6 volts
Pins 2 & 3 (Engine running at idle and normal operating temp) - 2.2 volts
** Reducing Voltage Increases Richness **
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12-05-07, 15:37 GMT+10#11 so the afm has something to do with spark?i have another one there that ill swap in to try.anything else please tell cause im desperate!
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12-05-07, 15:59 GMT+10#12 I dont believe the AFM is related to spark. My post was just to give knowledge to anyone in regards to the AFM.
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10-06-07, 21:15 GMT+10#13 i dont understand which pins you test...the ones on the afm itself or on the plug?
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24-08-07, 21:08 GMT+10#14 While the AFM is plugged in, slide the boot back on the plug, then push the probes of the multimeter into where the wiring goes into the plug.
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16-10-07, 13:39 GMT+10#15 Hey Guys
I used to work at a place called
INJECTRONICS in Hallam Vic.
They deal in reco AMM and also sell a heap of CAS's.
We sold a heap of VL AMM!!!
If you guys are having trouble diagnosing give them a call they have a FREE technical support help line ... the guys there Steve and Shannan will be more than happy to help you out.
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24-11-07, 19:16 GMT+10#16 Quote:
Originally Posted by HoldenOn
I had a Formula VLT which I sold last year which was runnin 12.3sec 1/4 miles with stock ECU and one extra injector controlled by microfueller. My tuner told me the settings for the AFM which I used to always stick to and it was perfect. Here are the settings;
Pins 2 & 6 (Ignition on but engine off) - 3.6 volts
Pins 2 & 3 (Engine running at idle and normal operating temp) - 2.2 volts
** Reducing Voltage Increases Richness **
Hey which way do the pins run??
1 2 3 4 5 6 OR 6 5 4 3 2 1
My AFM is a Bosch unit but has N0 pin numbers but some are numbered so I've been told..
Some original photos have not been recovered yet.
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30-11-07, 19:15 GMT+10#17 Anyone know the pin numbers on the AFM, pin 4 and pin 5 don't mean **** if you don't know which 1 is which
Some original photos have not been recovered yet.
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30-11-07, 19:31 GMT+10#18 all your AFM info http://wiki.r31skylineclub.com/index.php?title=AFM
Some original photos have not been recovered yet.
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30-11-07, 19:37 GMT+10#19 [QUOTE=theVLguy]all your AFM info http://wiki.r31skylineclub.com/index.php?title=AFM
That's fantastic VLguy thanks
Wonder why mine hasn't got the pins numbers
Some original photos have not been recovered yet.
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26-02-08, 19:47 GMT+10#20 Crank Angle Sensor, if you replace it you must do the top bearing too!!!
Because that's the most likely thing that killed the CAS in the 1st place..
Buy the kit and it has the CAS of course, new rubber boot, 4 terminals, plug, bearing and instructions...
Some original photos have not been recovered yet.
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