Ignition timing gremlin on a 86 monte carlo SS

[Robenstein]

So one of my Monte Carlos has a persistent gremlin. I checked the code and it was an ignition module code. Since the car needed a tune up I changed the cap, rotor, plugs, and wires when I changed the ignition module out. However, when I popped the timing light on it, cause its still doggy..even for a stock smogger 305 the timing is not advancing.

so could this be the electronic spark control module or would it be a computer perhaps? I looked all over for damaged wires and its all intact. It is still throwing the same code. It runs smooth but just has NO POWER at all. I can see why almost none of these have the original ecu controlled carb and distributor on them still. They are such a pain to keep working as they get older.

 

[JasonC]

I would think it would be the electronic spark control.

 

[The_Jeff]

There's usually a bypass wire where the distributor/ spark module tells the computer, okay, I'm over 400 RPM, you take control and set the timing please.

IIRC it's just a +5v signal that you can probe for. The computers are not beyond failure.

 

[Robenstein]

Well I will try the spark control module and see what happens. If it was not a 95% condiiton low mileage numbers matching car...Id be tearing all that [censored] off and putting a regular HEI and quadrajet on it.

 

[The_Eric]

Originally Posted By: eljefino
There's usually a bypass wire where the distributor/ spark module tells the computer, okay, I'm over 400 RPM, you take control and set the timing please.

IIRC it's just a +5v signal that you can probe for. The computers are not beyond failure.


You beat me to it!


Robenstein, give an extra close look at the 4 pin connecter that plugs into the module. I did one just the other day where the pins were loose and making (in my case) intermittent contact. Sometimes it would die and other times it would run poorly. A visual inspection revealed 2 pins that were opened up about twice what the other two were. One was the by-pass wire (like mentioned) and the other was the reference wire.

Luckily, the connector is still available.

 

[The_Eric]

Okay so I lied, in your case I think it's a 5 pin connector.

 

[Robenstein]

Yeah I checked all that when I did the tune up. It is all kosher. Plug ins are tight on the harness as well as on the ignition module. Thinking its got to be the spark control module or computer. It runs smooth without stumble it just makes absolutely no power at all.

 

[mechtech2]

You already changed the ignition module?
Sometimes you have to throw parts at it.
Testing a computer costs time and money.
Maybe a boneyard computer is you best next step.
Worth a shot.