TBI distributor conversion

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.


Feb 19, 2002
Washington, DC
Thought I would share the info here, since I know there has been a number of TBI conversion distributor questions.

I started with a trashed 78 distributor, that was rusty and the shaft barley turned. This particular distributor had slop where the pin holds the drive gear to the shaft, and it was probably 4-5 degrees at the distributor, which would 8-10 degrees at the crank. Not Good.

since this was a problem, I chose to drill out the pin, and replace it, to remove the slack it had. Once I got the pin drilled, I pulled apart the distributor, and pulled the shaft, cleaned up the distributor, and got ready for the TBI conversion...

I removed the centrifugal advance weights, and tried to figure a way to secure the reluctor(star wheel) shaft to the main shaft. I did not want to tack weld it, as I try not to permanently modify parts, so I came up with the idea of safety wiring the pins that have the weights and springs. I had some .040" stainless safety wire I used on my boat, and it worked great. bend the wire in a U, pull tight against the pin to shape the wire to the pin, put a few twists in it before the second pin, wrap around the second pin and twist until the slack is gone. Did this twice on the main pins, and a simplified version on the small stopper pin.

There is no play whatsoever in the two shafts, so i feel it will be fine. you could bend the pins over before the wire breaks if you tightened it up too much so I doubt it will break all three. Also since stainless, its not going to rust and fall off either. I still need to get a 6mm dowel pin to pin the gear back on the shaft, but they arent to hard to find at a good hardware place, although they are discontinued from toyota.

Moved on to the breaker plate and the pickup unit. Since this distributor had a bad pickup, I needed to get another. A trip to the parts store shocked me that the pickups were $145!!! Not going to pay that. With some help from the parts guy at the counter, I discovered that the pickup from a 81 cressida was exactly the same with the exception of the rubber grommet, and only cost $32 at kragen. You will need to trim the grommet(to fit the round hole), and pull off the plastic connector housing to get it installed but is easy. Even the plug is the same. Fitment on the breaker plate is identical.

Next, I needed to figure a way to lock the breaker plate down since I wasnt going to be using the vacuum advance canister. Came up with a sorta "L shaped piece of sheetmetal and drilled the holes to hold it to the breaker plate retainer screw, and the two screws that hole the pickup to the breaker plate.

Lastly, and I dont have a pic of it now, but there is now a leftover hole to fill where the vacuum advance canister once resided. A simple brass freeze plug solved that problem... Tap it into place with a little sealant on it, and youre done.

Hope this helps!

Kragen part number for Niehoff pickup is: WA936C
mechanical advance lock.JPG

Users who are viewing this thread

Top Bottom