summit 850005 distributor ECM conversion kit

yup i bought one for "Maybellene's (see profile pic)" 440...the package works ok..no issues related to it. The engine builder installed the distributor tho...engine ran fine on the dyno test. Once the engine was back in the car, I am having problems with vacuum advance. I think it's related to the holley carb...too much timing advance with the vacuum advance connected to the timed vacuum port. Seems like the port is pulling vacuum at idle. Disconnected and plugged it and things run better? not a final solution but good enough for now.

So, Summit's wiring instructions are ok, i had no prior experience with electronic ignition...only points. Wired it up and seems to work fine ex the vacuum advance issue. For the money the package seemed like a good buy to me as the points distro installed in the car was toast.

Dave
 
I'm not clear on what to do with the stock ballast resistor - I saw this diagram

http://www.forwardlook.net/forums/forums/get-attachment.asp?action=view&attachmentid=53820

get-attachment.jpg


where the guy took the 'start' and 'run' IGN switch circuits and combined them onto one side of the new ballast resistor + BLU wire to ECU.

the other side of the new ballast resistor goes to + coil, and he re-purposed the unused GRN 5th wire for this.

at the old original ballast resistor, he just took what was there and put them all onto the same post and left it there.

based off this diagram below that is supposed to illustrate the original wiring, the above wiring diagram looks legit, because this diagram below makes it look like the original ballast resistor is only there to kick down the 'running' voltage to 9v, but 'starting' voltage 12v bypasses the ballast resistor for when you are starting the car.

IgnitionDiagram.jpg



how did you wire yours in?

- saylor
 
so i wired it straight out of the instructions...two wires on each side of the ballast resistor with spade clips or connector for the coil. here is a pic from the instructions. When I get home I will take a pic of how i wired it together and post it...

upload_2017-9-8_15-47-53.png


Here is the link: https://static.summitracing.com/global/images/instructions/sum-850003.pdf

the extra unused wire from the control box i just left coiled up and tie-wrapped.
 
dmac thanks i forgot to post the summit instructions heh..

what did you do with the original ballast resistor and wires that are on either side? looks like left side is 'run' side and right side is 'start' side?
 
The kit comes with a new ballast resistor so i used that and old one went into the save parts box.

For each side I made a "Y" using 2 wires for each side. Female space clip to ballast and then 1as I remember male space clips to connect to existing wires for either start or run. The other side of "Y" went to coil or control box based on side.

Will post pics when home from work.
 
I did one of these about 20 years ago worked really good. The 68 GTX that belongs to one of my customers had the conversion on it, ran pretty good but with the cam in it I had to modify the advance so it only had about 13-15 degrees and put the rest in the initial timing. It liked more initial
 
here are the pics on how i wired it up to match the instruction diagram
upload_2017-9-8_18-40-3.png


in troubleshooting rough idle, i added a ground wire from engine to firewall ground strap like this:
upload_2017-9-8_18-40-52.png


and finally here is the unused wire from the controller box i tie-wrapped up and let dangle...lol.

upload_2017-9-8_18-41-59.png


hope this helps, the set up from summit seems solid to me.

Dave
 
Suggestion - mount the ECU on a bracket like the factor did on '72 and up cars. The bracket allows air to circulate around the ECU keeping it cooler, which will make it last longer and keep the black gunk on the back from melting and running down the firewall. An E Body reproduction bracket works just fine or there is one that has slots that can mount the ECU on the back of the engine that can be mounted anywhere.
 
dmac! thanks for the pics!

upload_2017-9-8_18-40-3-png.png


in this pic ^^. your 'start' side looks like it has 2 wires from factory BR (brown)and DBL(dark blue), where you added the RED wire-to-coil.

i guess maybe my confusion is, doesnt this same DBL wire on the 'start' side already go to + coil from factory? i.e. why are they having us add a new RED wire? could not the existing factory +coil wire be used?
 
hmmm good question. Since there was no coil on the car when i started working on her...I just created wiring as i needed it...mostly to match the instruction diagram.

I do see the second wire off the start connector...I am gonna have to run that wire down now and see where it goes. If the dark blue wire off that connector is dangling, it could go to the coil thus not needing the red wire and "Y" connector I created. It may be next weekend before i can get an answer...too hard to work on her during the week...unless my curiosity gets the best of me.

great question!

Dave
 
LOL i would not go that far! my curiosity got the better of me...I checked the dark blue wire off the start factory plug and it is indeed a coil wire. So, in hindsight, i probably should have checked that first. This weekend I will replace the start "Y" with the factory wiring and connect the dark blue wire to the coil. will simplify the wiring...which is always a good thing!

Thanks again for the great question!

Dave
 
Saylor your car on points is wired that way. The ECU just takes the.place of the points (grounding or not grounding the coil) collapsing the field in the coil making high voltage spark.
 
beautiful information here dudes thanks. it looks like this thing just drops in with the stock wiring + the 2 new leads from the new harness easy peasy.
 
saylor said:
beautiful information here dudes thanks. it looks like this thing just drops in with the stock wiring + the 2 new leads from the new harness easy peasy.
Click to expand...
Basically put power in, ground out to - on coil and plug in magnetic pick up. +Side of coil stays same as points set up.
 
ya like what is there stock on a points distributor car converting to ECU control box - does the voltage regulator change as part of the swap, or it does not have to?
 
Saylor, The stock mechanical type voltage regulators fail quickly with an electronic ignition conversion. Your options are to buy the solid state replacement like the ones that I sell or to convert to the '70 & up voltage regulator.

Bill
 
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