CAS testing? No spark/no fuel

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jeffball610
Too Much Time on His Hands
Posts: 619
Joined: Wed Feb 22, 2006 5:29 am
Location: Las Vegas, NV

CAS testing? No spark/no fuel

Post by jeffball610 »

I have no spark and no fuel. Fuel pump works and pressurizes the system. The engine turns over. 12v is present on all appropriate wires and grounds are good. This is what I've done to test the CAS itself:

Pins #1 and #2 on the CAS test as 5v with ignition on. #3 tests as 12v and #4 is a ground. So wiring should be fine. I don't have a testing procedure for the CAS itself, but have tried the one in the car and a separate unit by spinning them and there is no reaction from the ECU or motor letting me know they are working. They could both be bad, but that seems unlikely.

Is there a way to "manually" send a signal to the ECU and see if the coil or injectors will react? Maybe ground one of the 5v wires? I'm at a loss. What else can I test?
Do it in a Datsun!
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons and rods, Garrett GT3076R, "flipped" stock intake, Toyota R154, Z31 R200 w/ CVs
jeffball610
Too Much Time on His Hands
Posts: 619
Joined: Wed Feb 22, 2006 5:29 am
Location: Las Vegas, NV

Post by jeffball610 »

Wow. 2 weeks and no one can help? I'm still not any closer to finding an answer. I did manage to do a little testing on 2 spare CAS that I have. One is a 90 and the other is a green top 91+.

What I've found:
Not much. Black next to red is ground and red is 12v. Duh. White is the RPM signal. Duh. It seems to output 5v when the outer ring (pictured below) has an open window under the sensor. It's signal doesn't seem to change for the inner ring. The other black (or just as dirty white on the 90 unit) has a signal between -30mv and 160mv. The signal goes negative when the inner window passes the sensor.

This is very rudimentary testing with me using a 12v battery and a multimeter on a test bench. It still doesn't account for my lack of spark or fuel. My next guess is ECU. I've tried to rule it out since ECMLink rebuilt it several years ago and socketed it for Link.

My stupid old school Palm Pilot won't connect to my car's cable and resets itself every time I try wiping out the memory so I have to resynch with the computer (running Windows XP) so I can't see if the ECU has any good signals.

I'm open to ANY suggestions. I pulled the wiring harness last night just to double check that all the wires went to the right places. And they do. I'm at a complete loss.

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Do it in a Datsun!
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons and rods, Garrett GT3076R, "flipped" stock intake, Toyota R154, Z31 R200 w/ CVs
jeffball610
Too Much Time on His Hands
Posts: 619
Joined: Wed Feb 22, 2006 5:29 am
Location: Las Vegas, NV

Post by jeffball610 »

My CAS is good. All the testing I did helped me to understand what was going on, but the whole issue was a bad connector. The wiring tested good, but there was a bent pin that did not allow the signal to be sent to the ECU causing all of my frustration. A friend spotted it and it now runs. #4G63510 officially runs! I can't stop smiling :) Video in the build thread is forthcoming.
Do it in a Datsun!
1972 Datsun 510
7-bolt 4G63T, EVO 9 pistons and rods, Garrett GT3076R, "flipped" stock intake, Toyota R154, Z31 R200 w/ CVs
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