1970s 1979 Electronic Spark Selector

[bcroe]

Just got a report from another 79 Eldo owner, their
ignition quit, but was restored by converting the HEI
from the ESS system with 5 pin HEI module and firewall
delay module, to a 77 system with just the 4 pin HEI
module.  Owner very happy.  Not unusual, this was the
last (we hope) of a series of car issues, ECU repaired,
timing chain set replaced, pump relay installed. 

Previous discussions by Scott Kent covered a lot of
this.  The 78-80 5.7L EFI used the ESS system, which
was inactive most of the time.  Replacement ESS parts
are in the unobtanium catagory. 

I did establish, our 5.7L HEI with EFI speed sensors
has a shaft about 0.32 in longer than the carb version. 
And the housing too.  So my idea of putting a new
(readily available) Olds shaft assembly in (after
drilling for the magnet pin) will not work.  Bruce Roe

[TJ Hopland]

I didn't know that those 5 pin modules had disappeared but it looks like they have.  They were used on some other makes in 80 I think and used to at least be listed as available. 

I no longer remember the details but there was a 'hack' use for those I thought I wanted to do at one time so I think I had collected a couple of them back when I used to frequent the U pull junkyards.  I will have to keep an eye out for them and pass them onto someone that can use them if I still have em.  I think the hack may have been to use them to retard during cranking if you had a really aggressive build.

I had not looked recently but you used to be able to buy the internal harness for the normal 4 pin HEI so I would not think converting one would be that big of a deal.  I can't remember was the pickup coil end different so you would have to change the pickup if you swapped em too?   

Was the vacuum and or mech advance different on the ess units too so that is why you were looking at changing the whole assembly?   

[bcroe]

I didn't know that those 5 pin modules had disappeared but it looks like they have.   

I no longer remember the details but there was a 'hack' use for those I thought I wanted to do at one time so I think I had collected a couple of them back when I used to frequent the U pull junkyards.  I will have to keep an eye out for them and pass them onto someone that can use them if I still have em.  I think the hack may have been to use them to retard during cranking if you had a really aggressive build.

I had not looked recently but you used to be able to buy the internal harness for the normal 4 pin HEI so I would not think converting one would be that big of a deal.  I can't remember was the pickup coil end different so you would have to change the pickup if you swapped em too?   

Was the vacuum and or mech advance different on the ess units too so that is why you were looking at changing the whole assembly? 

I found the mechanical and vacuum advance were
the same as the non ESS HEI.  The harness that
goes to the cap is the same, 4 pin module just
plugs in. The pickup coil then just connects to
the other end, white outside pin (W), green
inside pin (G).  If a non ESS pickup is swapped
in, it already has a 2 pin connector for this. 
The firewa;; module may be removed. 

The ESS required pickup timing a few degrees ahead,
so it could then delay it for most operation. 
If the ESS is removed, timing must be retarded
a bit to get back to normal. 

A hack for a bad firewall module, was to just
unplug it and add a jumper between pins 2 & 4
on the connector to the HEI, still using the 5
pin module.  Check Timing.  Bruce Roe

[Seville Life]

Hi Bruce, Paul here in the UK.

I was surprised to read of the longer distributor shaft and casting on the EFI Seville and Eldorado motors? The block is a standard Olds 350?

I don't follow how a regular distributor won't fit into the block and mate correctly with the camshaft?

[bcroe]

Hi Bruce, Paul here in the UK.

I was surprised to read of the longer distributor shaft and casting on the EFI Seville and Eldorado motors? The block is a standard Olds 350?

I don't follow how a regular distributor won't fit into the block and mate correctly with the camshaft?

An Olds HEI will fit just fine, sitting 1/3 inch
lower.  But it has no Speed Sensors, so cannot be
used to trigger injection in the 70s Cad EFI. 
Bruce Roe