GM HEI 7-pin module differences and catalog errors

[brianl703]

For the 7-pin module used with the external ignition coil, there appears to be two different ones that otherwise look identical.

One is SMP LX-316, and the other is SMP LX-325.

The LX-316 is listed for a handful of mid 80s Jeeps and nothing else. I am sure that is a catalog error.

The LX-325 is listed for pretty much everything else that ever used this 7-pin module with an external distributor, EXCEPT the 1984 Chevy Cavalier. SMP lists NO ignition module for the 1984 Cavalier.

From what I can determine by cross-referencing parts, the AC Delco D1962A module is the correct one for my Cavalier (and is obsolete), and that crosses to the LX-316.

Others list ONE module for everything, like NAPA -- they list the TP49 for all of these applications.

Both modules look like this:

 

[brianl703]

I've been unable to find any information about the differences between these modules, and it appears that both GM and AC Delco had several different part numbers for them.

I even tried looking for old part catalog PDFs with a Google search to see if I could find any old AC Delco or SMP part catalogs that listed the 1984 Cavalier, no luck.

Alldata says the ignition module part # for that 1984 Cavalier is 1997107 which is obsolete from GM and I haven't been able to cross it to anything.

 

[brianl703]

And to make things even more confusing, SMP lists the LX-325 module for the 1984 Pontiac J2000 2.0, and the 1984 Cadillac Cimarron 2.0, both of which uses the same ECU, ignition coil, and distributor as the 1984 Cavalier that they don't list any module for (but which according to the AC Delco D1962A cross, should be the LX-316).

What I wouldn't give for an SMP or AC Delco catalog from the 90s...

 

[JHZR2]

Hopefully @clinebarger can shed some insights…

Otherwise is there an old cavalier enthusiasts forum?

 

[paulo57509]

RA shows the D1962A as available. If you need it, place your order. There's only one left.

RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

 

[clinebarger]

The only thing that could be different is the Dwell in Bypass Mode, Once the ECM (EST) takes over (EST/Run Mode)....What module is employed makes no difference.

Dwell differences on a 4 cylinder in Bypass Mode isn't likely to cause issues, But if it were to....It would be during cranking/starting.

 

[brianl703]

RA shows the D1962A as available. If you need it, place your order. There's only one left.

RockAuto

RockAuto ships auto parts and body parts from over 300 manufacturers to customers' doors worldwide, all at warehouse prices. Easy to use parts catalog.

www.rockauto.com

Strange, it wasn't showing up a couple days ago. Maybe someone found one in a warehouse under a shelf.

I found a new old stock D1961 module on Ebay. I put it in my watchlist and the seller made me an offer for $11.20. Offer accepted, came out to $17.34. The D1961 is supposed to be equivalent to the D1962A module.

With a box this old, I bet it's made in USA:

 

[brianl703]

The only thing that could be different is the Dwell in Bypass Mode, Once the ECM (EST) takes over (EST/Run Mode)....What module is employed makes no difference.

I found this in a Transpo/WAI catalog from 2011:

Interestingly, the 1.8L 1984 Olds Firenza takes the DM1967 module. The 2.0L 1984 Olds Firenza (same as the 1984 Cavalier) takes the DM1961 module (per Rockauto catalog).

 

[brianl703]

I had called my cousin in Chicago who is a manager at an auto parts store to see if he still had old catalogs. Unfortunately, they don't anymore.

But today I was at a NAPA that I know has been there for a long time (I remember buying a turn signal bulb for a company car from them back in 1995!) and I asked the guy there if they have any old catalogs. Told me his manager isn't in but probably still has them in the office, said he never throws anything out.