1991 Geo Metro Won't Start

I have '91 Geo Metro 1L 3-cyl. Spark plugs have been replaced, tested and no spark. Ignition coil tested and I get 12V. Plug wires are good. Distributor checked and looks good.

I bridged the ECM and got a trouble code of 41, ignition signal. I found on the internet a schematic/flow chart reflecting that fact I’m not getting an ignition signal could be either the coil or the noise compression filter. The coil was replaced and still the same issue, engine turn but no start.

There’s mention of a test I could perform with a multimeter on the noise compression filter, however, I don’t know what it looks like or where it would be located. Does anyone know?

Second question, at first I thought it was the starter, but I have had a few gents tell me that the starter motor sounds strong. Would it be worth my effort (minimal effort to get to and pull out) to get tested?

Have you tested the pickup coil in the distributor and the ignition module for this no-spark condition?


Thanks! That’s the next on the list of items to test. I’ll post results once I have them.

So, we have figured out that the culprit is in fact the ignition module. Thanks for pointing me in the right direction.

Would the repair manual help you to troubleshoot this problem and show you where the ignition noise suppression filter is? If that were shorted, it could cause problems.

I have one that shows an electrical diagram of where it is in relation to the ignition coil and the distributor cap, however when I look under the hood, I do not see what/where it is. If you or someone has a picture of what one looks like, then I could see about eliminating it since now I know the ignition module is bad. Thanks!

So the final verdict: a timing belt with lots of missing teeth. That has been replaced and it is not running, however a bit rough which seems to indicate the timing is off a bit. Thank you all for your advice.