Alarm cause no-start?

[seningen]

Originally Posted by Turbodad

Installed a new battery it started. let it sit for a few minutes because the AOS tube had come loose and it would not start. Changed the starter last week. Checked relays and fuses. I installed a matched set i got a few years ago with a swap engine and no joy...

My case is not starter related (well at least in the normal sense).

My car is a race car and is wired to crank even with the DME removed -- i.e. where the DME pin 66 would drive the start activation lock with VSS, my relay is hardwired to ground on pin 85.


That being said -- I am still working on this problem (abet with some interruptions caused by life).


What I know. (lets ignore the will start with jumper voltage --- that hasn't worked lately).


No fuel pressure, No gnd on pin 85 from DME (pin 63). Fuel pump is fine as I have a Fuel pump run switch which turns on fuel pump, and I get good pressure.
Connectivity from pin 85 to DME pin 63.

No fuel injector firing (noid light doesn't turn on)

12v on MAF pin
5v on MAF pin (low volt)

Sent DME off to be tested. It tested fine, but I had the Immob requirement removed anyways. (www.ecudoctors.com)

CPS provides a good signal and missing tooth and signs of decent cranking speed.

Not sure if I have spark -- difficult to test. I have a magnetic spark detector -- but I haven't
had it running to observe it working -- so I don't know if I have no spark -- or a user error
with the spark detector.


I have ~0.4v drop from battery through all cables to starter when cranking -- which seems reasonable.

Battery voltage while cranking remains >10v.


Next steps -- although they are more difficult to do because I'm not sure how to monitor the DME pins with the DME connected.

DME
Observe Pin 63 (which I can get at the Fuel Pump Relay)
Observe Pin 66 (which would be at the Start Lock Relay, but is not since it's connected to ground)

Observe Pin 12 to see if the DME is being sent a shutdown signal (or lack of OK signal)

Check to see where the Clutch interlock signal goes -- I can't find it on my wiring diagram.

I know normally it won't let the starter engage -- but I'm not sure the exact mechanism.


QUESTIONS:

What is the normal operation of pins 63 and 66?

Does pin 12 shutdown the DME == and if so what is the normal "OK" value?

Where and how does the clutch interlock signal enter the system?


I'm about this close to buying a cheap POS Boxster -- just to have a known good reference.


thanks,

Mike

[seningen]

Found pin 66 in the wiring harness that was taped up as my spec boxster is weed for push to start. This is the pin that should connect to hand to let the starter relay engage.

It’s reading 12v as is pin 63 which is the fuel pump relay.

I had the dme checked and it’s good.
My dme has also been modified to provide its own immob code.

What are the inputs required to allow the dme to be happy?

Something is telling my dme not not allow the car to start.

Thx,

Mike

Originally Posted by seningen

My case is not starter related (well at least in the normal sense).

My car is a race car and is wired to crank even with the DME removed -- i.e. where the DME pin 66 would drive the start activation lock with VSS, my relay is hardwired to ground on pin 85.


That being said -- I am still working on this problem (abet with some interruptions caused by life).


What I know. (lets ignore the will start with jumper voltage --- that hasn't worked lately).


No fuel pressure, No gnd on pin 85 from DME (pin 63). Fuel pump is fine as I have a Fuel pump run switch which turns on fuel pump, and I get good pressure.
Connectivity from pin 85 to DME pin 63.

No fuel injector firing (noid light doesn't turn on)

12v on MAF pin
5v on MAF pin (low volt)

Sent DME off to be tested. It tested fine, but I had the Immob requirement removed anyways. (www.ecudoctors.com)

CPS provides a good signal and missing tooth and signs of decent cranking speed.

Not sure if I have spark -- difficult to test. I have a magnetic spark detector -- but I haven't
had it running to observe it working -- so I don't know if I have no spark -- or a user error
with the spark detector.


I have ~0.4v drop from battery through all cables to starter when cranking -- which seems reasonable.

Battery voltage while cranking remains >10v.


Next steps -- although they are more difficult to do because I'm not sure how to monitor the DME pins with the DME connected.

DME
Observe Pin 63 (which I can get at the Fuel Pump Relay)
Observe Pin 66 (which would be at the Start Lock Relay, but is not since it's connected to ground)

Observe Pin 12 to see if the DME is being sent a shutdown signal (or lack of OK signal)

Check to see where the Clutch interlock signal goes -- I can't find it on my wiring diagram.

I know normally it won't let the starter engage -- but I'm not sure the exact mechanism.


QUESTIONS:

What is the normal operation of pins 63 and 66?

Does pin 12 shutdown the DME == and if so what is the normal "OK" value?

Where and how does the clutch interlock signal enter the system?


I'm about this close to buying a cheap POS Boxster -- just to have a known good reference.


thanks,

Mike