5 terminal HEI module

[Mark Eidson]

Has anybody tried to use the teeth on the flywheel or flexplate as a timing
source?  me

At 08:35 AM 10/23/96, you wrote:
>
>     Thanks John,
>     
>     With the 5-pin module essentially breaking the pick-up to coil driver 
>     connection, this would be ideal for replacing the esc module with an 
>     aftermarket ecu for the timing.  Just need to modify the pick-up wheel 
>     I think (need to examine the ecu instruction manual to see what is 
>     suggested).  
>     
>     Do you know how processed the pick-up signal is when it goes to the 
>     esc module ?  and do you know what signal the esc module uses to drive 
>     the coil driver in the ignition module ? 
>     
>     I'd hate to start to try and fit a big tooth wheel and pick-up as well 
>     as coil driver to connect the ignition side of my ecu, if I can simply 
>     use a 5-pin module (and maybe some filtering) to do the job.
>     
>     Dan        dzorde at aesprodata.com.au 
>
>
>______________________________ Reply Separator
_________________________________
>Subject: 5 terminal HEI module
>Author:  diy_efi at coulomb.eng.ohio-state.edu at INTERNET
>Date:    10/21/96 9:25 PM
>
>
>dzorde asks about the function of the 5 terminal HEI module. This was an 
>early control system for knock control only. The distributor (dizzy?) still 
>had centrifugal weights and a vacuum advance.  The positive line of the two 
>wire pickup coil is sent to an ESC controller, instead of going right to the 
>HEI module as in the 4 terminal variety. If the ESC controller is not 
>detecting any knock input it simply allows the pickup coil signal to return 
>to the module and fire the coil. If it does detect knock, it DELAYS the 
>return of the pickup coil signal for a time equal to the numbers of degrees 
>of retard it commands, based on a lookup table in the ESC controller. The 5th 
>terminal is simply used as the line to return the pickup coil signal on. It 
>was an early, rather crude method of knock retard, but was perceived as a 
>great accomplishment at the time. I make this assumption based on the size of 
>the "ESC" emblem they used to put on the tailgate of trucks equipped with 
>this system. When I am doing a repair on these systems, most customers allow 
>me to just loop the positive pickup coil wire back into the module and throw 
>the ESC controller away!
>     
>                John Spears 
>Speartech Fuel Injection Systems
>     
>
>
***************************************************************************
* Mark Eidson                        Voice: (602)752-6513                 *
* Staff Design Engineer                Fax: (602)752-6000                 *
* Manager System Integration and                                          *
*   Verification                    E-Mail:  mark.eidson at tempe.vlsi.com   *
* VLSI Technology, Inc.                                                   *
* 8375 South River Parkway                                                *
* M/S 265                                                                 *
* Tempe, Arizona     85284                                                *
***************************************************************************