Whit3Angel

I've been helping a friend with his s13. His car needed a new motor so he bought a used s13 dohc that had a blown head gasket. We replaced the gasket and buttoned the motor up. We get the motor in the car and wired up. Try to start it but it wont start.
Checked over the wiring harness to make sure we didn't miss anything. That's fine.
Checked to make sure it's getting fuel. That's fine.
Next we check spark...There's no spark leaving the coil.
I test the resistance of the coil and it's at about 1.3ohms. Get another from the junk yard that checks out fine and still nothing.
I'm stumped on what the problem is. Anyone??

Empire

could have replaced a bad coil with another bad coil.
junkyard coils typically aren't good.
don't know why... maybe they don't like the dust in the air or something.

I'd say spend the 80 bucks and buy one of those blaster coils from the part's store and wire that in.
As I understand it, the same thing that tells the injectors to fire is the same thing that controls the coil.
I could be wrong. I'm honestly not 100%
but if it was my car, that's the route I would take. I would verify that the injectors are actually firing (not just think they are, but see them spraying with my own eyes) if they are, then it would lead me to believe it is the coil itself.
If they aren't actually firing, then it is more than likely the CAS in the distributor that is bad, or at the very least, the plug.
that's where I would start.



Why did you need a new engine?
is it the same ECU from the old engine?
how do you know the coil isn't sparking?
Are you getting 12 volts to the coil?
(the ecu tells the coil when to fire by grounding it, not by charging it, so there should be 12v to the coil when the key is on)

Whit3Angel

I'll check the injectors tonight.
He needed a new engine because he blew up his first one.
The ECU is the same from the old engine he also has another ECU laying around
I took the coil wire from the distributor and held it next to a ground to see if it sparks.
Yes the coil is getting 12 volts with the key on.

Empire

I'm really hoping it is the CAS in the dizzy. swap the dizzy out, and it should fix the problem.

I figured it blew up, I mean, do you know why it blew up. If the ECU failed and flooded all of the injectors, hydro locking the engine, then that might be the problem this time. Or if the alternator tweaked the hell out and overload the system frying the ECU.

Is there a working car that you could yank the ECU out of real quick to check it out. I'm not a big fan of the "laying around ECU" they can break by getting banged around. even a little bit. I mean, it is worth a shot to swap out, but I wouldn't feel comfortable ruling out the possibility of a bad ECU by using that ECU. know what I mean?

Good. Just making sure. A lot of people will say "It isn't sparking" but never actually check it to actually see if it is or isn't sparking. So 2 points for you!

if the coil is getting 12v then, at least to me, it narrows it down to either being the coil itself, the ecu, or the CAS.

Whit3Angel

It turned out to be the connector for the distributor. One of the wires on the original connector broke so we took another connector from the harness he had laying around and spliced it in and I accidentally connected the wrong wire to another. Got that sorted out and it sparked every time!

Now we just have to get the timing right :/ but that's a pain in the ass!!!