93 Lumina dies while driving

[Dave Lehrke]

My 93 Lumina will fun fine for awhile and then unexplicably start misfiring until it dies. It will eventually restart and run fine for awhile again before repeating the problem. I have replaced the fuel pump, strainer, plugs, air filter, and put a new computer module in. It now is giving me an error code of 42. Any ideas?

[jdl]

When the problem is ongoing, when it dies, if it cranks good but won't restart for several seconds. Have a helper crank it, while you check for spark at the plugs. If there is no spark, that might be the easiest way to track it down.

Common causes for code 42, frayed or broken wires between the ignition module and computor. The color of the wires, white--tan/black--purple/white.

We can talk about the signal on those wires, but below 400 rpms, I believe, the computor has no control over the spark, that's why I started with spark.

[Blue Bowtie]

Welcome Aboard!

Is this regarding a 191 inch (3.1L) V-6? If the ignition system has the triple coil pack, verify the connections at the ignition control module (mounted beneath the three coils) and verify a good ground for the ICM on its mounting plate.

The error code is indicating a problem with the ignition timing, and since the timing is controlled by the ECM through the ignition module, that's a good place to start looking.

The ECM also relies upon inputs from a crank position sensor, so you may end up checking that as well, but the intermittent nature of the problem is going to make diagnosis a bit more difficult.

[richtazz]

here's a link to a nice write-up on the GM code 42. Hope it helps

http://www.troublecodes.net/articles...ndrstd42.shtml

[starla3366]

I know its the IGNITION MODULE for a fact. Absolutely positive!!!

The module has a heat sheild on it that is notorious to fail. Sounds to me like your module is getting hot then failing out. That's the reason why it will start right back up after letting it cool for a bit.

JunkYard are the best place to get them from. Cause Auto stores want like over 100 bucks for them.

The secondary fix which is well worth doing anyways is the Crank Shaft Sensor (CSS)

cheers