Duraspark mess

[PistolPete]

Hi all,

I've got an 86 inline 6.
The previous owners attempted a duraspark conversion but did not do it correctly. The feedback carb and EEC module have been removed and a HEI carb is in its place. However there is no DSII module installed.

The truck runs, however when I go to start it and turn the ignition I lose my voltage. I have to feather the ignition to get the voltage to start the truck.

My neighbor and I have been trying to troubleshoot but are having difficulty.

We found the red/lt blue wire on the passenger side of the engine that gives 9volts, and currently there is a red/lt blue wire hooked to the solenoid "S" point that provides 12 volts. Nothing is connected to the "I" point.

I've attached pics. Any help would be appreciated!
20240628_082532.jpg20240628_082525.jpg20240628_082539.jpg

[Gary Lewis]

Ok, now we are getting somewhere.  You have an HEI ignition.

Second, to show pics please go to Bullnose Forum/Forum FAQ's in the menu for how to do that.

Third, the HEI REQUIRES a lot of current or it will not run correctly.  What usually happens is that someone connects the HEI to the original R/LG (not R/LB) wire that supplied power to the coil.  But that wire runs through a resistor, as you can see in the EVTM (Documentation/Electrical/EVTMs/1986 EVTM) and is NOT the wire you want to power the HEI.

To make the HEI work properly you must install a relay that is triggered by key-on power - like the R/LG wire or W/LB wire.  Go to our page at Documentation/Electrical/Ignition and then the Ignition Simplification tab followed by the One Wire tab.  There you'll see a schematic for the relay and a description of what wires to use to power it and pull it in.

[mat in tn]

the beauty of the hei is the one wire simplicity but that is extremely misleading. you must have enough current and voltage to run it. in order to get that you need a heavier wire then the previous system required. you need to add a relay in order to carry the added load. you should be able to find diagrams here in documents. having used a few of these, I'm not opposed to them, but they are not my first choice. bulky. and on a v8 they are in the way of the air cleaner. not so on the i6. we have had them fail in a week. I prefer the duraspark 2 to the thick film/ecu hybrid but I must say my original truck is still original ignition so I cannot complain. 86 inline 6 thick film with yfa.

[85pig]

If the 86 is anything like my 85, Ford left all of the connectors there for a DSII conversion.  Simply find an earlier 80s truck with the 300 and DSII, and scavenge the harness from the distributor to the blue grommet box.  It's plug & play.  

[PistolPete]

Hey Gary,

Thanks for the info! I ended up adding a relay and the truck starts right up!

I've learned a ton working on "Brenda" and I think I finally have her in proper working order.

[Gary Lewis]

PistolPete wrote

Hey Gary,

Thanks for the info! I ended up adding a relay and the truck starts right up!

I've learned a ton working on "Brenda" and I think I finally have her in proper working order.

Excellent!  

[mat in tn]

score one for pistolpete!

[85lebaront2]

I have told many people about the current draw of the HEI systems. When Government Motors (who are notoriously cheap) used an 8 or 10 ga wire to feed the HEI system, you know it's a power hog. I have determined it is apparently the coil, as the Lucas Constant Energy system uses a GM HEI module fed by the normal ignition wiring for their OPUS systems.

Conversion procedure was to remove the ballast resistor, unbolt the coil and using the longer bolts provided, remount the coil with the constant energy box underneath it. Install the new distributor and connect everything, start car and set timing.

[Gary Lewis]

Bill - Wasn't there a TSB from GM where they instructed the dealerships to upgrade the power feed wiring on some vehicles?

[85lebaront2]

Gary, I wouldn't know, I never owned a GM vehicle with HEI. My 1963 Jetfire had breaker points until I put a prototype electronic trigger on my Delta Mark 10B in the distributor. All my other GM cars were Diesels.

[Gary Lewis]

Ok, I was thinking that there was a recall or TSB where GM realized they'd put too small of wire in the harness to the HEI.

Delta Mark 10B.  Still have one of those.  Put one on that 72 F250 but kept the points.

[85lebaront2]

The breakerless convesion required the breaker plate to rotate GM style rather than swing like Ford or Chrysler. Ford did build the early V8 units with ball bearing breaker plates. I had one on the 1957 312 I had in my 1958 F100 and one on the MEL 430 I had in my 1958 Country Squire.