Another 1981 question
Thread Starter
Heel & Toe
Joined: Jan 2025
Posts: 19
Likes: 1
From: Montana
Another 1981 question
Hey guys, so, my ECU is a bad actor, and the distributor has seen far better days, and the carb is just flat used up. Instead of replacing all of those I decided to just replace both the Q-jet and the dist with the standard, non-feedback upgrade parts.
I got the new HEI distributor from Summit along with a three prong pigtail;
The OEM wiring on the cap has the normal red/hot battery wire, and the tach wire, and then on the pass side approx where the Vac advance usually is, is a 4 wire weather pack connector. Which I believe goes to the ECU, oe ECS, which ever you want to call it. I got another pigtail with the distributor that connects behind the other two mentioned wired on the cap, drivers side as usual. But not certain where to splice those. So that is the main question here, where do I pick up those needed wires for that 3 prong plug?
Thanks in advance for any insight on this one.
I got the new HEI distributor from Summit along with a three prong pigtail;
The OEM wiring on the cap has the normal red/hot battery wire, and the tach wire, and then on the pass side approx where the Vac advance usually is, is a 4 wire weather pack connector. Which I believe goes to the ECU, oe ECS, which ever you want to call it. I got another pigtail with the distributor that connects behind the other two mentioned wired on the cap, drivers side as usual. But not certain where to splice those. So that is the main question here, where do I pick up those needed wires for that 3 prong plug?
Thanks in advance for any insight on this one.
Race Director
Joined: Mar 2017
Posts: 11,907
Likes: 4,479
From: Virginia
Do you have a wiring diagram, and a shop manual and assembly instruction manual for your 81?
Wiring diagrams are here:
https://wordpress.keystonestatecorve...m/?page_id=118
You should probably return that distributor, and get one with a 4-pin HEI module and vacuum advance can. It should only be two wires to connect (switched IGN power, and tach signal). It sounds like you bought a direct replacement for your 81, but if you are deleting the ECU, and the computer controlled carb, it won't work (or will run like garbage with no vacuum advance).
Wiring diagrams are here:
https://wordpress.keystonestatecorve...m/?page_id=118
You should probably return that distributor, and get one with a 4-pin HEI module and vacuum advance can. It should only be two wires to connect (switched IGN power, and tach signal). It sounds like you bought a direct replacement for your 81, but if you are deleting the ECU, and the computer controlled carb, it won't work (or will run like garbage with no vacuum advance).
Thread Starter
Heel & Toe
Joined: Jan 2025
Posts: 19
Likes: 1
From: Montana
Great advice brother, but this one turned out stranger than that after I got back into my shop today for a second look. Turns out the hi-po distributor Summit sent me was missing that 3 wire plug i knew they all have coming out of the distributor body which plugs into the cap, right? And, there was also a pigtail of that exact plug in the package, but not inside the box with the distributor. So, my first look I thought, wtf? do I have to splice in somewhere else? Long story, they are sending me a new complete product this time. Yikes.. Thanks for weighing in.
