Davis Unified Ignition HEI installation for noobs (2 Viewers)

[leathamtj]

Hello Again and thank you for helping me out.... I have a 1987 fj60. Not the vacuum advance but I am guessing on the 60 only there are two vacuum lines on the top of the distributor cap. One goes into the cab and the other is the standard 3mm vacuum line. I bought the Davis hei distributor for a 2f... this one should have the Toyota gear correct? Thanks for the help and if you feel like I am hi jacking your thread let me know and I will post my question elsewhere. Anyways, thanks again.

 

[HawkGunner]

Hello Again and thank you for helping me out.... I have a 1987 fj60. Not the vacuum advance but I am guessing on the 60 only there are two vacuum lines on the top of the distributor cap. One goes into the cab and the other is the standard 3mm vacuum line. I bought the Davis hei distributor for a 2f... this one should have the Toyota gear correct? Thanks for the help and if you feel like I am hi jacking your thread let me know and I will post my question elsewhere. Anyways, thanks again.

If you bought the one for the 2F, it will have the Toyota gear.

As far as the vacuum lines go, the one that went into the firewall gets plugged and is no longer used. The one that goes from the carb to the dizzy, goes from the carb to the vacuum advance diaphragm on the HEI. It should be pretty straight forward.

When you set the timing, you'll pull the hose from the diaphragm and plug it. Once timing is set, unplug and reconnect to the diaphragm. If you've wired everything properly, and set the timing properly, you should be good to go from this point.

 

[leathamtj]

That’s awesome! Thank you!

 

[Loomis Blue]

Awesome write up and exactly what I needed.
Thanks to Coolerman for the harness and
to HawkGunner for the info.

 

[JHeffner]

Getting ready to install this on Saturday. This has been a lot of help.

 

[HawkGunner]

Getting ready to install this on Saturday. This has been a lot of help.

Good, I'm glad its helping someone.

 

[tone33]

Ditto that - great writeup. Thanks for taking the time to do it! I'm wiring up my DUI dizzy now. Learned the hard way that I can't turn off the engine with the key unless it's wired through the ignition (duh) lol.

 

[jetyancey]

I did my DUI this today, plugged the vacuum off for the carb side and the vacuum advance. Set the timing, then when I plug the vacuum back up -hei vac to manifold- it swings wildly and sound like a huge cam in a hotrod then dies. Any idea why? Almost seems like the vacuum is too strong

 

[Steamer]

I did my DUI this today, plugged the vacuum off for the carb side and the vacuum advance. Set the timing, then when I plug the vacuum back up -hei vac to manifold- it swings wildly and sound like a huge cam in a hotrod then dies. Any idea why? Almost seems like the vacuum is too strong

Un-related to your timing issue but did you pay attention to the mounting shim washer and what it does.?

 

[jetyancey]

Un-related to your timing issue but did you pay attention to the mounting shim washer and what it does.?

I fit it with and without the washer. Both engaged the oil pump, without bottom-out

 

[Steamer]

What did you set the timing at? Are you de-smogged?

 

[jetyancey]

What did you set the timing at? Are you de-smogged?

Yes sir, de smogged, capped both vacuums off and set it to 12°. I have a Holley 7448 with a vacuum port on the side, it may be metered down some. I’ll try it next, The manifold vacuum can suck the paint off the hood.

 

[ryanwk628]

I did my DUI this today, plugged the vacuum off for the carb side and the vacuum advance. Set the timing, then when I plug the vacuum back up -hei vac to manifold- it swings wildly and sound like a huge cam in a hotrod then dies. Any idea why? Almost seems like the vacuum is too strong

Ported vs manifold vacuum would be different at idle. I’ve seen different literature on which is better and different recommendations from DUI, but it seems ported was created for emissions reasons, to burn more of the particulates in the exhaust but can make that side run hotter

 

[jetyancey]

Ported vs manifold vacuum would be different at idle. I’ve seen different literature on which is better and different recommendations from DUI, but it seems ported was created for emissions reasons, to burn more of the particulates in the exhaust but can make that side run hotter

I just plugged it up to the carb/barb and it’s definitely pulling a lot less vacuum. Idling smoothly so far. Test drive will tell. I sincerely appreciate everyone here on MUD. I’m no mechanic, but through this website I’ve restored a 1977 Land Cruiser to a very nice daily driver. My build is on instagram @7740STORY. It’s been a good ride. The gentleman I bought it from has been a wealth of knowledge, passing that torch to me

 

[jetyancey]

Well, the test drive didn’t make it far. It did not like hooked to the Holley 7448 vacuum barb on the carb. Wondering the work-around is for this

 

[KingAir Driver]

I run my DUI with the vacuum plugged at the distributor and just use the mechanical advance, seems to work great through all driving ranges. I have a 73 though with stock carb and no manifold vacuum port, only ported, and it ran like crap.

 

[moorencompany]

MASSIVE thank you to everyone's input on this. Installed my DUI on my 78' Piggy this weekend and could not have done it without this thread. I've tried to add a few bits of my learned experience below. I'm even more of a newbie than @HawkGunner and had to really break this down into bite-size chunks (and drawings).

Removal of old dizzy
- Remove spark plug wires from top of distributor.
- Take the cap off of the distributor
- DO NOT PULL YOUR DIZZY YET. Instead, take a photo of the top and make note of where the internal "pointer" is pointing. (this will help you when re-installing your new dizzy)
- Slowly pull your dizzy out & watch how the "pointer" turns ~30 degrees on the way out. This is because of the teeth on the dizzy shaft & their engagement.

Wiring
- Because the DUI needs more power than a stock dizzy, you'll need to make a wire relay system which @HawkGunner laid out for us. I've gone ahead and made a visual reference of this.
- Shopping list: 4-prong relay, 12ga wire, wire cutters/crimpers, male & female quick disconnects for the wiring, heat shrink tubing, 15-amp in-line relay
- Build your relay as my visual shows (photos of the actual relay also below)
- I'm a nerd and labeled each side of the relay box as well as each wire connection so I didn't screw anything up. Hell, I even labeled the 15amp relay.
- Heat shrink tubing was used for each connection to ensure longevity. I tried to use the liquid tape like HawkGunner did and found it to be way too messy for my liking.
- I ran terminal #85 to the negative battery connection instead of grounding it to the body. (either way works)
- Mounted the relay box a bolt that holds my battery mount to the frame. Could have put it anywhere in the vicinity but this gave me really good access to the wires.

Moving your heater hose
- You may not have to deal with this, but I did. The new dizzy is massive compared to the stock one and would not fit with the heater hose mounted to the engine block the way the factory installed it.
- I unbolted the two bolts that held the metal heater hose piece to the block to get it out of the way and just ran a new pice of 3/4" heater hose from the radiator to the heater hookup at the firewall.

Continued in part 2 below...

 

[moorencompany]

Part 2...

Gap your spark plugs
- Buy a spark plug gapper, gap your plugs to .50 to .55
- Amazon product ASIN B00144AZ6K
Installing your new Dizzy, Plan A
- FOLLOW THE DIRECTIONS THAT COME WITH YOUR DUI. These have already been posted in this thread previously.
- I ended up using only the thin shim that came with the unit to help seal the connection from the shaft flange and keep the oil from coming out. I didn't have any bottom-out issues.
- Remember that photo that you took of your old dizzy when you took the cap off? Now is the time to study that real hard and work to put your new dizzy in the same way. I DID NOT do this and had to resort to plan B (see below).
- If you did take this photo, have verified that your dizzy shaft is NOT bottoming out, and you're ready to roll...
- Turn the dizzy "pointer" 30 degrees clockwise to where it was in the photo. This means that if the dizzy pointer was pointing directly at the passenger side headlight when you pulled it out, you would rotate it to point at the driver's side headlight (roughly). This will allow the dizzy to engage with the teeth on the way down, turn 30 degrees counterclockwise (from the driver's side headlight back to the passenger side headlight) and settle right into place just like your photo.
**DISCLAIMER. Even if you took the photo (which, again, I did not), I think my Plan B of finding Top Dead Center is a better option.

PLAN B
- Because I didn't have any idea where my old dizzy's "pointer" was pointing, I had to start from scratch which was to find Top Dead Center (TDC) on Piston #1 and work my way from there.
- To find TDC (the point where your #1 piston is a the highest point of its stroke), I had to:
- Pull the #1 spark plug
- Rotate the motor manually to manipulate the pistons so that piston #1 is a the top of it's stroke using the huge bolt on the bottom/front of your motor where your belts attach to or use a long screwdriver to do the same.
- Also keep an eye on your flywheel for the BB or a line etched on it. In my case I had a BB AND a line that were 180degrees off from one another. I mistakenly thought that I had TDC when I lined up the etched line and I was actually 180 degrees off and had to find the BB instead.
- A helpful tip here was to plug the opening of the #1 sparkplug with my thumb while someone rotate the motor. I could feel the air pushing against my thumb indicating that the piston was on the way up. When the BB showed up on the flywheel, I knew I found TDC.
- Now that you've found TDC, it's time to drop your dizzy in. The attached instructions saved my life. Follow them step by step.
- Word to the wise: you'll need to use a long screwdriver to make sure that your oil pump slot (at the very bottom of the opening in your motor where the dizzy shaft goes) will line up with the dizzy shaft. This might take you a few tries to get right.
- Aim the dizzy "pointer" 30 degrees clockwise (almost at the #3 spark plug). This will allow the dizzy to engage with the teeth on the way down, turn 30 degrees counterclockwise and settle right into place pointing just to the right of the #4 spark plug (see the attached PDF for photos of how this should look).
- Finger tighten the dizzy clamp bolt (you'll need to turn the dizzy for timing so don't crank it down).
- Once you're here, you're almost home.

Install Dizzy Cap, Hook Up Spark Plug WIres, Hook-Up Power
- The DUI dizzy cap does NOT have numbers on it which I thought was a factory mistake. Turns out they know exactly what they're doing and I had no clue what I was doing (shocker).
- With your dizzy "pointer" aimed just to the right of the #4 spark plug and your #1 piston at TDC, when you put your dizzy cap on, the pointer should be VERY close if not directly pointing right at a connection for a spark plug wire on the cap. Congrats! You've just found where your #1 spark plug wire connects.
- Go ahead and connect the remaining spark plug wires in the correct firing order going CLOCKWISE. In my case, I'm running a 2F which has a firing order of 1-5-3-6-2-4. A great way to remember this is the saying "15 is too young, 36 is too old, 24 is in the middle..."
- Go ahead and hook up the 3-pin connector from the bottom of the dizzy to the cover just like it came in the box.
- Then connect the 12ga wire from terminal #87 off of your relay into the "BATT" connector on the dizzy.
- Your motor should fire right up.

If motor doesn't fire
- You may be 180 degrees off from TDC like I was. If your motor isn't firing, find TDC again using the same steps as above and pull your dizzy cover. If it's pointing exactly opposite of the #4 spark plug, you have joined my 180 club and will have to pull your dizzy and re-install.
- If you are right where you need to be and it still won't fire...I'm no more help to you. Sorry

If motor fires, let's get to Timing
- I reached out for help locally to borrow a timing light from a Rising Sun 4x4 club member here in Denver because I didn't want to purchase one.
- With the motor running, we hooked up the adjustable timing light and pointed it at the flywheel with a setting of 0.
- Very gently, I turned the distributor until the BB was hitting the indicator line perfectly. This meant that we were at 7degrees which is the factory setting.
- We then adjusted the timing light to 6 degrees to get to our advanced timing of 13 degrees. Once the BB was landing on the indicator line, I clamped the dizzy clamp bolt down tight and we were done.

Here is one last photo of the finished product that I hope is helpful.

And one more photo highlighting where I ran the heater hose below the dizzy.

Hope this helps someone in the future.

Other threads that were lifesavers:
https://forum.ih8mud.com/attachments/1654180573123-png.3023289/
Distributor Installation - https://forum.ih8mud.com/threads/distributor-installation.1285708/#post-14467209

Help with timing - DUI dizzy install on a 2f rebuild

Hey all, I’m currently in the process of installing a rebuilt 2f in my 76’, wondering what the steps are to install the HEI DUI dizzy that I already had, and correctly time the engine? Thanks, any help is appreciated!

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