Can a non-ECM controlled HEI be used on a 88 TPI retrofit to a 50's street rod? Will the ECM still function correctly?

------------------

 

The ignition control is 1/2 of what makes EFI so neat.
If you isolate a neg coil side trigger to an ignition module you can. But then you have to disable the ignition malfunction flags.
I'd really suggest more research for doing that..

 

The functionality and precision hasn't escaped me - I was just curious if it could be done. Sounds like you may not be 100% sure?



------------------

 

I'm sure it can be done but my electrical circuit skills are not good enough to help you. Maybe an engine tech or Mallory/MSD/Accel certified person can help?

You basically have to repropgram the PROM major, OR

Have to fake the computer into thinking that it is still controlling/creating spark. My guess would be to leave the CC-module connected OUTSIDE the distributor and have the old-style HEI distributor under its own circuitry, which it is anyway. But, you'll also have to send an rpm signal to the external module for obvious reasons. ie, the Pickup coil signal of the old-style HEI will have to be tapped in to...

Just not sure how to make the (now) external CC-module operate properly (without any spark being generated) so that the ECU thinks it is operative???

[This message has been edited by FastBroker (edited January 05, 2001).]

 

Or just use a "computer controlled" HEI distributer which is better anyway, and get rid of all these headches. LOL

------------------
92 Z28 L98 350
---------------
Ported stock heads, XR270HR-10 cam, TES headers, Crane AFPR, Flowmaster catback, MSD ignition components.
Best ET 13.5@105 mph
"Take that auto, drop it in first, hold the brakes, stomp the gas and grin from ear to ear! :-)
Click here to see my car at Truspeed.org

Check out TruSpeed at http://www.truspeed.org
Check out the Bin Archive at http://www.truspeed.org/bins.html

 

Sure anything can be done. From your letter it sounds like your not an EE, and neither am I. So while possible, I know I'd be leary of recommending what I'd try for you to run. There are all sorts of gotchas on automotive electronics that even a non automotive literate EE can miss.

 

I guess I'd just be curious as to why you'd go with TPI if you didn't intend on using an ESC distributor. Not saying there couldn't be any good reasons not to, I just can't think of any offhand.

 

Well, I probably wouldn't but I was just kinda thinking out loud to myself about this retrofit I'm going to do. If the existing curved HEI works well with my non-stock cam and I'm not ready yet to get into PROM editing and burning and I can richen the mix some with an AFPR, I thought it might be a way to get the system up and running for awhile and perhaps perform a little better than running the stock ECM configuration. It would be an experiment - isn't that what hotrodding is about? Fortunately, the vehicle is not my daily driver.



------------------