Aight, new car new problems.
Bought an -87 z28 305 TBI that has been standing since 22 or 23.
According to legend it was running when the previous owner stopped using it.
By the looks of it, it has been standing outside for at least a part of that time (leaves, twigs and dirt gives it away)

The add said "no spark". So yeah, no spark.
Coil, distributor/rotor, ignition cables seems fine.
Rigged a coil from an working Camaro and nohting.

It cranks as it should. Just no ignition.
Well... First time we tried to start it, it actually gave a slight cough, twice. But dead since that.
(That was what made me think I can get this bucked of bolts to run again)

So...
Need help thinking, since I am a **** mech and should stay away from old cars
ECM, is there any way of determine if its broken?
Is there any relay or fuse that can cause this?

 

https://easyautodiagnostics.com/gm/4...-tests?start=5

 

Sounds like the ignition module is toast. Replace it

 

Two easy things to check: 1) cheap rotors can arc out to the center mounting post in the distributor. If it were an issue, you have to look for a hair-fine arc line with an eye loupe. The spark goes from the coil to the coil connection on the distributor cap, but nothing comes out to the plugs when it completely fails. It is intermittent before that.
2) The pink and white wire coil jumper harness is a known failure point. Remove it and check for corrosion and test it with an ohmmeter.

 

Sounds like an anti-theft measure to me.
If the VATS does not send the proper signal to the ECM, the ECM will not pulse the injectors.

When you turn the ignition on, does the SES light turn on? At least that would be a response from the ECM.
Look up how to bridge the contacts in the ALDL connector using a paper clip and you'll see how the SES light responds. If an error code has been set, it will flash it to you.
Code 53 indicates the VATS signal is not reaching the ECM.

So these are your options the way I see them:
- Code 53 + crank: VATS module not sending signal to ECM or ECM is faulty
- Code 53 + no crank: VATS issue or key has wrong resistance. You can find valid resistance values online, then measure your key's resistance and compare
- No code: Faulty ECM or other issue

 

I think you posted on the wrong thread. 87 doesn’t have vats and spark other then advance is independent from the ecm.

 

The easiest way to check that is to pull the starter enable relay and jump the two fat wires. If it starts you got your answer

 

And it's also a TBI, which I didn't notice before.
Thanks for the hint!

 

Buy a test light and hook the clip to the neg post of the battery. Turn the key on and see if you have power at the coil, no power and you're never getting spark. Then touch the test light probe to the tach wire and crank the engine over and the light should blink on and off. No blinky you have a problem in the distributor primary circuit either pickup or module. If good blinky start checking at the coil and through the distributor cap. Of course all of this assumes the distributor is going round and round.

 

Ign fuse good?

 

Ty for the link. Helped.

Was the ignition module.
To be more exact, the pins at the back (that connects to the small coil in the destributer) was so corroded that they had no connection and when I tried to take them apart on of the pins simply came of.

 

If there was corrosion on the icm . You might consider changing the pu coil. It probably has corrosion as well.