COP problems

[rlacasse1]

OK. A little history. My 90 TSi had a fried coil pack so me and my brother decide that we would try to build a COP for it. It took about four different tries because all the wiring diagrams i found weren't labeled for which cars they would work on. anyway finally got the right diagram and it works. however only the number 1 cylinder won't fire. i tried 3 different coils on it and none would work right. I put a spare plug in the coil to see if it arcs between the plug and engine to check if it works and it will spark fine, but as soon as i actually touch the plug to any metal the spark goes away. i also put in a new plug.

i tried to find the wiring diagram again so everyone would know how i wired it but i couldn't find it. anyway it came off this website.

anyone have any ideas on why only one coil will do this

 

[jeffo]

Without a wiring diagram I don't really know how you have it wired, but the coils for cylinders 1&3 should be wired in series with each other, so anything affecting cylinder #1 *should* also affect cylinder #3. Is that how you have it wired? You basically have +12 volts coming in at one end of 2 strings of 2 coils, #2 and #4 in one string, and #1 and #3 in the other string. The +12 volt feed wire is usually a heavy black/white striped wire. You should also have 2 wires coming from the transistor, Yellow/Green striped and Yellow/Black striped I believe. Each of those wires drives the other end of one of the strings of coils. That's all you need to make it work, but there is also the matter of the 1990 tach driver module, which has 2 inputs that need to be tied to the Yellow/Green and Yellow/Black wires also, and the tach output drives a white wire in the harness that feeds both the ECU and dash tach.
keydiver

 

[rlacasse1]

coil 1 and 3 are in a series and coil 2 and 4 are in another series.

if i unplug cylinder 1 it kills cylinder 3.

i just don't get why only cylinder 1 isn't working. i tried different coils and still nothing.

i used a test light and checked the wiring a little. the wire from the harness that has a constant 12V signal divides and goes to cylinder's 1 and 2.

the other two wires which are signal wires. go to 3 and 4. can't remember off the top of my head exactly which one goes where.

anyway cylinders 2,3,4 are all firing but cylinder 1 isn't

 

[Sp1kE]

I followed this and made mine work
http://www.dsmtuners.com/forums/bol...ug-ignition-merged-1-8-a-4.html#post151113740

 

[Sp1kE]

remember to note how the tach box is wired up so you can keep your tach .

 

[rarest_90_DsM]

I'm new to this whole coil on plug thing i also have the same problem i just cant get over why 1 and three are in series and 2 and 4 are in series the motor has a specific firing order and this does not make sense if you think about it 1 and 4 should fire at the same time and 2 and 3 should fire at the same time hence the firing order on the stock coil 4,1,2,3 4 and 1 are on a coil and 2 and 3 are on a coil so why is everyone telling people to wire the car with a firing order of 1324? can anyone explain to me why my theory is wrong any car after 91 is wired correctly cop series together 4 and 1 and 2 and 3 so why are we wiring 90s differently they have the same firing order and coil with the advent of a tach adapter. if we wire them in series 1and4 and 2and3 and splice in the tach adapter shouldn't it work?????
please anyone explain why this theory is wrong?