Seoul Seven

I recently put my motor in and everything and tried starting it about 10 min ago. (fresh rebuild) Smoked abit while it turned over but did not start. I smelled LOTS of gas and pulled the plugs and gas came out. i deflooded the motor then tried again coming to the conclusion i have no spark.

pulled the plugs to watch the ignitors and only one sparked. it was the T2 ignitor.

satch

iTrader: (1)

One thing you need to do is verify whether or not you have battery voltage with the key to on at each of the coils and more importantly the leading coil. At the leading coil there is a white two wire plug and one of these wires is Black/Yellow. This is the wire that should read battery voltage w/key to on.

misterstyx69

iTrader: (142)

Check the plug wires,and also check or replace the plugs on the trailing side.
then recheck the Spark.It could be that simple.
I Did have a Trailing coil that would only fire one plug off.It was a bad trailing coil assembly.I found it a little weird too,but it does happen.

datz

i have similar problem, my leading coil doesnt work.
the black/yellow wire is constant ~12v but the green/yellow wire reads nothing, shouldnt the ecu pulse a ground signal on that wire, so you would see that wire pulsating ~12v while the engine is running?

HAILERS

Green/yellow cycles from 0-5vdc to fire........lead coil assy. Turn the crank pulley by hand while watching a meter and you should be able to see that happen.

satch

iTrader: (1)

If I understand correctly, the wire you speak of normally has a ground signal on it then the wire will flash a voltage signal very briefly then it goes back to a ground signal so the wire is really pulsing a voltage signal as opposed to a ground signal. The fuel injectors would be different as the wire which pulses a ground would normally have a voltage signal on it which would prevent the injector from firing until the wire has a ground sent through it thus allowing the injector to fire. So in one instance, injector example, the wire pulses a ground while in the other instance, the coil, the wire in question pulses voltage.

The test suggested by HAILERS will get you on the right track to diagnosing your problem. If you don't get the voltage bump on the wire in question then either the problem lies within the wire itself, the CAS or the ECU or even perhaps the AFM.

datz

I found that bump of about 5v but the igniter/coil
ohms within FSM limits, ut it still has
no spark.

satch

iTrader: (1)

How are you visually checking for spark? Perhaps you could pull a plug wire from the coil itself and place the plug wire as close as you can to the bore you removed it from while still leaving a space between the two and try to start the car and look for the existence of spark. This usually would require two people to do. Also, is the leading coil definitely bolted down to the fender so as to provide a proper ground for the igniter? If it is not grounded satifactorally it will "not" fire.

Seoul Seven

OK well im getting spark. I got fuel. Compression. And played with timing.

im still having a hard time starting it. Its a fresh rebuild and this will be the first time starting it so i understand its gonna be hard. lastnight we cranked it and push started it..well tried and it would kick over and sputter a bit with pushing it but would not keep going.

and now just 5 min ago i deflodded it and its sparking the motor over but it seems like its not enough of a "boost" to bring it alive just yet.

datz

the plugs and plug wires are brand new. I took the plugwire off the plug, took the plug out, put it back in the wire,held with pliers with the threads grounded, and started but no spark.
I'll try your suggestion.

HAILERS

The rise and fall of the voltage on the G/Y wire of the LEAD coil assy's small white plug proves the CAS is good and the ECU is good.

The rise and fall from 0-5vdc is what fires the ignitor for the LEAD coil assy.

The assys ignitor and its electronics get their ground from the lead coil assy being held to the chassis with at least one of the four fasteners that hold it to the chassis. So make sure at least one of those fasteners is holding the lead assy to the chassis.

Usually I can take either of the two lead coils sparkplug wires out of it bore in the lead coil assy and rest that wire just at the edge of the coil bore. Then spin the engine and see a large spark b/t that sparkplug wire and the bore of the lead coil assy. If memory serves I can do the same thing just by hand turning the pulley with the key to ON and the sparkplug wire laying just at the edge of the lead coil assy's bore.

IF you had a spare CAS you could attach it to the cars harness and just spin the bottom gear of that spare CAS with key to just ON and hear and see spark. Saves wear and tear on the starter and rotor housings and confirms spark or lack of. Engine does not have to turn over when doing this. Just key ON.

As far as I'm concerned you proved the CAS.....its wiring to the ECU and the ECU are good when you see the riise and fall of the voltage from 0-5vdc over and over as you turn the crank shaft over by hand.........with key On.

datz

I'm not near my car so I can't check it out until a day or so, but from what I've done and heard from you guys I'll bet it's not grounded right or at all.
thanx guys, very informative