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Tech / General EngineIs your car making a strange sound or won't start? Thinking of adding power with a new combination? Need other technical information or engine specific advice? Don't see another board for your problem? Post it here!
as I am digging into this car and the gremlins, when I look up modules or Dizzy's for this rig, I'm getting the distributor that has the "flat" side with two plugs, not the typical HEI large cap, that I replaced on my car. As I am new to these motors, and I know the ECM controls timing, now I'm paranoid that I was throwing 1987 parts at this thing, however I did replace the stock, or what appeared to be the stock A/C Delco distributor with a Chevy plug and play DUI, maybe I'm over thing this. P
ics are what I have on what is at least a 90-92 ECM
Re: 90-92 Computer, 7 pin Ignition control module?
Yes, the '90 - '92 f-body TPI set ups used the small cap distributor with the remote coil. You can ask for '90 - '91 y-body (Corvette) distributor parts as they stayed with the big cap distributors.
Re: 90-92 Computer, 7 pin Ignition control module?
Originally Posted by JeepingDrake
as I am digging into this car and the gremlins, when I look up modules or Dizzy's for this rig, I'm getting the distributor that has the "flat" side with two plugs, not the typical HEI large cap, that I replaced on my car. As I am new to these motors, and I know the ECM controls timing, now I'm paranoid that I was throwing 1987 parts at this thing, however I did replace the stock, or what appeared to be the stock A/C Delco distributor with a Chevy plug and play DUI, maybe I'm over thing this.
You can use the one you bought (the fat cap HEI). I swapped to one on my '90 GTA from the small cap to reduce the clutter. The wires leading to the distributor from the ECM need to be inverted, and you'll need a female/male connector half from a fat cap setup coming from the ECM (which will be the piece you invert) to attach to the large cap's male connector coming from your distributor...
- Rob
Last edited by Street Lethal; Feb 24, 2021 at 09:26 AM.
Reason: Was more specific...
Re: 90-92 Computer, 7 pin Ignition control module?
So does it really matter if there is a large cap in the car vs small cap? Am I missing something here in my ignorance? The car ran fine until recently. waiting for my data cable from Moats.
Re: 90-92 Computer, 7 pin Ignition control module?
Originally Posted by JeepingDrake
So does it really matter if there is a large cap in the car vs small cap? Am I missing something here in my ignorance? The car ran fine until recently. waiting for my data cable from Moats.
As long as the big cap distributor clears the firewall, no, it doesn't matter which one you use. If the wiring is for a big cap, and it looks like it is. Then stay with it.
I have no idea why GM changed between large and small cap distributors (maybe inventory on hand?). I've run both in various vehicles. Didn't matter to me as long as it cleared the firewall (big cap won't on 1st gen f-body cars, but does on the El Camino).
Re: 90-92 Computer, 7 pin Ignition control module?
Doesn't he need to run the ANHT/AXCN Vette spark latency tables if he's running the big cap distributor?
The tables are significantly different between AXCN/ANHT and the Camaro AUJP.
My recent experience with modules vs latency tables shows you can get very different results in the spark timing being commanded by the ECM vs what comes out at the distributor.
