Which Ignition Control Module do I need....ACDelco D1943A or D1984A ?

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someotherguy

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The two different modules in question regarding performance differences were referred to "in the old days" as # 369 and # 048, with the 369 being "better" ... how those #'s cross to modern day part #'s I have no idea. I used to keep a few known-good OEM modules in my toolbox and had several 369's on hand.

There's also the "Dyna-Mod" which is supposed to beat the 369. That is, if you believe what ya read - here's some info from Thirdgen; you'll want to overlook all the latency table business unless you are in to custom tuning work.



Why the Dyna-mod says it fits 87-93 V8 I don't know; I would expect it to fit 94-95 as well but if you're those year models I'd just call and ask them.

Richard
 

PlayingWithTBI

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The two different modules in question regarding performance differences were referred to "in the old days" as # 369 and # 048, with the 369 being "better" ... how those #'s cross to modern day part #'s I have no idea
Yeah, that's the one I remember, ha ha. Thanks for looking it up :waytogo:
 

someotherguy

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Yeah, that's the one I remember, ha ha. Thanks for looking it up :waytogo:
I went out to the garage to see if I still had a 369 kicking around in one of the boxes.. all I could find was a Chinesium Delphi with an "X" on the box meaning it's probably bad, and most likely my last 369 went into the truck when the Delphi crapped out. :D

Richard
 

Jackalope400

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I think I have gotten to the bottom of it......I called ACDelco (800-223-3526), and with my VIN, he said the D1943A is the correct ICM. He said that was the only ICM listed for my truck, and he didn't show the D1984A as appropriate, even though his web site for consumers that I used does also show the D1984A, and Rockauto also shows them both. I pressed him why when I enter my VIN on their site, it comes back with both ICMs. He just said that internally, they have other resources available that is for their employees, etc. He said with my VIN, he can see exactly how they originally built it with what parts.

So I also asked him to look up the D1984A and see if it showed any other relevant info. He did, and he said that ICM is only for engines L86, LS0, LR0.

I'm satisfied D1943A is correct for my L05 engine. Hope this helps anyone else who may have run across this.


Hey there, Your post led me to calling like you did to get the correct part for my vin. Thanks for posting your results. Saved me some time.
 

1990Z71Swede

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Bought an ACdelco D1943A/GM19179578 ICM today...
When researching P/N's I came across this:

FWIW, here's some random ICM info collected over the years. Sorry, but attributions lost
The ignition module is responsible for turning the ignition coil on and off and controlling the duration of current flow through the primary winding of the ignition coil. This allows the spark plugs to fire at a specific time according to the number of cylinders your vehicle has. It also controls dwell.

ICM stamped '048' (GM 10402827): Retarded the timing advance beginning at 3,500 RPM permitting the use of 83 octane gasoline and the module acted as a speed governor. It seems like the OE Code 048 Ignition Control Module acted like a rev-limiter and limited the ignition advance above 4,000 RPM.

ICM stamped '369' (AC Delco D1943A, GM 19179578): First used on the 1985-1993 Chevrolet Caprice with the 9C1 RPO Police option. This ICM does not retard timing starting at 3500 RPM, but provides 2 degrees additional advance from 4,000 to 5,000 RPM and a total of 6 degrees additional advance above 5000 RPM.

GM replaced the "048" ICM with the "369" ICM. The replacement may not have "369" printed on it. The "048" was discontinued so GM felt like there was no need to differentiate between the two. If the AC Delco D1943A module does not have "369" printed on it, look for the GM part number 19179578 burned on the edge of the module. The 19179578 8-pin ICM was originally for the 9C1 Police Option in a Caprice. In 1989 GM made the AC Delco D1943A ICM (19179578) as the service replacement for all V6/V8 models through 1995. That was because the TBI swirl port (fast burn) cylinder heads needed faster and more total advance. Engines with aftermarket performance camshafts need faster and more total advance.

HTH, Elky


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