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]

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 :

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]

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.

 

[Hawksfootball29]

I seem to be having the same problem. Car worked fine then out of nowhere I started it up and 1 and 4 aren't firing. I changed the ignition coil thinking that was it but it isn't. Before I bought anything else I thought I would see if you found a solution?

 

[BoostedTsiFWD]

I seem to be having the same problem. Car worked fine then out of nowhere I started it up and 1 and 4 aren't firing. I changed the ignition coil thinking that was it but it isn't. Before I bought anything else I thought I would see if you found a solution?

Test your cam sensor. Seems from what iv read that if its not a wiring issue. Changing coil packs, transistors or ECU's also does nothing. Than the cam sensor is at fault and needs to be replaced. Follow the steps to test and see if a supply voltage is being sent.

Heres a quick easy one. Try to start your car. Watch your tach. Tell me if it moves at all while your trying to start it.

 

[Hawksfootball29]

No it doesn't. and its kinda slow to get to idle once it does start..

I also just tested my transistor and it seems fine so im thinking its the CAS

 

[BoostedTsiFWD]

No it doesn't. and its kinda slow to get to idle once it does start..

I also just tested my transistor and it seems fine so im thinking its the CAS

Its your cam sensor but just to be safe do the test as described above to test it. Your tach should read about 200 rpm when trying to start. When it reads nothing its the cam sensor to blame. Unplug the cam sensor at the sensor itself and see if it still fires on two cylinders. These cars have both a crank and cam and one of them won't let any of the cylinders fire. I just cant recall which sensor it is.

If it still fires on two cylinders after unplugging the cam sensor than your cam sensor is at fault and needs replaced. Come back and let me know what happens. Iv been tracking this problem for the past week on my car.

Im 100% positive its the cam sensor in my case because a ECU swap did nothing. A new coil pack and transistor also did nothing. All of my wiring checked out too.

 

[Hawksfootball29]

Ok i will test it. My car is a 97 with a 1g motor 6bolt motor in it and im not sure if it has a Crank angle sensor but ill double check that. Thank you for the help

 

[awzer2]

Its your cam sensor but just to be safe do the test as described above to test it. Your tach should read about 200 rpm when trying to start. When it reads nothing its the cam sensor to blame. Unplug the cam sensor at the sensor itself and see if it still fires on two cylinders. These cars have both a crank and cam and one of them won't let any of the cylinders fire. I just cant recall which sensor it is.

If it still fires on two cylinders after unplugging the cam sensor than your cam sensor is at fault and needs replaced. Come back and let me know what happens. Iv been tracking this problem for the past week on my car.

Im 100% positive its the cam sensor in my case because a ECU swap did nothing. A new coil pack and transistor also did nothing. All of my wiring checked out too.

I JUST GOT MY CAR BACK from the shop,and it was A CAM SENSOR! i paid 230$'s tho

 

[BoostedTsiFWD]

I JUST GOT MY CAR BACK from the shop,and it was A CAM SENSOR! i paid 230$'s tho

So it was the cam and not crank? Just trying to be specific. I'm being told my cam sensor has been replaced.

 

[awzer2]

So it was the cam and not crank? Just trying to be specific. I'm being told my cam sensor has been replaced.

oh yeah, AND my crank was replaced could've been either or.
my cousin took my car for me.
i took my car first to a hot rod shop and they tried chargin 350 to solder some wires together . before diagnosing be careful.

 

[BoostedTsiFWD]

oh yeah, AND my crank was replaced could've been either or.
my cousin took my car for me.
i took my car first to a hot rod shop and they tried chargin 350 to solder some wires together . before diagnosing be careful.

It was probably the crank than. My cam sensor was replaced by the previous owner. Crank on the other hand hasn't been.

 

[Hawksfootball29]

ok so I have a 92 6 bolt motor (and a EPROM CPU) that has a black top CAS that im going to replace, but my question is can I use a green top as a direct replacement and it not change anything performance wise or am I better off just getting the Black top

 

[BoostedTsiFWD]

ok so I have a 92 6 bolt motor (and a EPROM CPU) that has a black top CAS that im going to replace, but my question is can I use a green top as a direct replacement and it not change anything performance wise or am I better off just getting the Black top

Im not sure. just do a search. The no coil fire problem on the 1g's seems to be the CAS crapping out and the CPS on the 2g's. Weird problem but the few threads i found where the problem was solved involved changing the 1g CAS or the CPS on the 2g when nothing else worked and all of your wiring checked out.

 

[Hawksfootball29]

Ok replaced coil, replaced CAS and still no luck. Coil isnt getting spark on 1 + 4. I guess Ignition Module is next to change? The CPU seems to be working because the CEL comes on at first then goes off after a while and i can still connect to DSMLink. Also i noticed that DSMlink says my RPMs are about 1000 higher then they really are??

 

[BoostedTsiFWD]

Ok replaced coil, replaced CAS and still no luck. Coil isnt getting spark on 1 + 4. I guess Ignition Module is next to change? The CPU seems to be working because the CEL comes on at first then goes off after a while and i can still connect to DSMLink. Also i noticed that DSMlink says my RPMs are about 1000 higher then they really are??

Go it it tested. Most Ign. modules can be tested by a local parts store. Make sure they run the test at least 10 times. They don't tend to fail till they warm up.

and why dont you test your voltage going to your sensor before you replaced it? Dont just buy stuff and throw it on. test it first man .

 

[Hawksfootball29]

It was getting 5v from plug so i thought the CAS might be bad. I also tested the ignition module by testing voltage between the prongs and it checked out ok. Also i have found some stuff saying the ASD/MFI relay might be bad? Im new to DSM so I dont know where to look for the next problem at.