Question about Ignition. Cylinders 4 & 1 not firing?

[GTPDan]

I'm generally new to the dsm community. I recently purchased a 92 awd tsi talon. It has ran great for a week and a half and just the other day it started with this no firing from cylinder 4 and 1. I have tried replacing both the ignition module and coil packs, spark plugs and wires and all of that ended in the same result in no firing in cylinder 4 & 1. I have a Haynes repair manual and checked the camshaft/crankshaft position sensor. Everything reads fine except for no supply voltage for the camshaft sensor on terminal 1. Would this sensor be the reason cylinder 4 & 1 are not firing? And also if anybody knows of a good site to go to, to get this part off the internet? Any posts or comments would greatly be appreciated. Thanks.

[Splitpi]

1&4 are on same coil pack. Check all connections to that pack. If nothing out of the ordinary, switch connectors on the 1&4 with the 2&3 such that the 2&3 now acts as 1&4 and fires 1&4 plugs normally. If the 1&4 plugs works after the swap and 2&3 now don't work, the it is your coil pack and you need to replace it.

[MidShipCivic]

Originally Posted by Splitpi

If the 1&4 plugs works after the swap and 2&3 now don't work, the it is your coil pack and you need to replace it.

No offense but he said :

Originally Posted by GTPDan

I have tried replacing both the ignition module and coil packs, spark plugs and wires and all of that ended in the same result in no firing in cylinder 4 & 1.

[steve]

Originally Posted by GTPDan

I have a Haynes repair manual and checked the camshaft/crankshaft position sensor. Everything reads fine except for no supply voltage for the camshaft sensor on terminal 1. Would this sensor be the reason cylinder 4 & 1 are not firing?

CAS pin 1 is the TDC sensor that tells the ECU when the engine is at cyl 1 and cyl 4 TDC. The CAS doesn't generate the voltage on that pin the ECU does and the CAS pulls the signal low to trigger. First thing to check is that the ECU is putting out 5v on the line when the CAS is disconnected. If it is and it goes low and stays low when you plug the CAS in then it's bad.
If you don't see 5v with it disconnected check the wiring and the ECU.

Steve

[GTPDan]

Thanks Steve. I'll try that out and let you know how the outcome is. Is there anything specific, like appearance of the ECU that I can look for that will tell that it is bad? Just tryin to get her out on the road.

[Vicious_mole]

i had cylinder 2&3 not fire once ended up being a cam sensor

[GTPDan]

Checked wiring. No problems there. No signed of knicks, burnt areas of wire or anything. Pulling ECU out when I get off work wednesday. I can definatley say that it is not the cam/crank sensor due to lack of signal voltage on the harness side of the connecter coming from the ecu.