DUI - Timing Question (1 Viewer)

[TheDurangoKidd]

I've had a DUI distributor sitting on the shelf for quite some time and finally decided to install it. The install went smooth thanks to all of the info I found here on Mud. I turned the key and she fired right up. Seamed to idle smoother than ever. I was stoked!

Here are my question(s).

I have a cheep adjustable timing light. I wanted to set the timing to zero to verify a starting point. Idle <650, vacume advance plugged, timing light is at zero, I twist the distributor to try to get the timing mark (not the bb) and pointer lined up. I turn the distributor clockwise until it won't turn any more, the mark is not visible. Turn it counterclockwise until it won't turn any more (about 1/4 turn), the mark is not visible. So I start adjusting the timing on the light. With the distributor turned fully clockwise and the timing light set at 18 degrees the timing mark and pointer line up? Am I wrong to expect the timing mark to be visible when the timing light is set to zero? I drove around the block like this and it ran just not smoothly. After rechecking everything I came to the same result, timing mark at 18 degrees. As an experiment I set the timing light to 30 degrees (18 base + the 12 the DUI calls for). She runs, runs pretty good. Pulled 4 gear from 1,300 RPM without stumbling. Pulled up a hill with no fuss.
What am I doing wrong? I have a guess but I'd like to get some feedback before I start changing things.

One other question. I don't know what to do with the vent line that runs from the fire wall just behind the windshield washer fluid resoiver to the top of the original distributor .

Thanks

 

[BlackCat]

The distributor is a tooth(s) off.
7°BTDC should be roughly centered on the distributor adjustment swing.

When I bought my truck years ago the base timing was at 22° due to the distributor being off a tooth.
And if you’re absolutely totally absolutely positive the distributor is stabbed right, then make sure you have the lead on the #1 plug wire.

 

[cruisermatt]

why would you set the timing to zero advance, or did you mean you were just trying to set it to the base timing? You need the spark to be ahead of TDC so the mixture has time to ignite before full compression. set your timing light to zero and it should flash on the base timing mark (The BB which is 7-degrees before the TDC line)

 

[OSS]

The vent tube through the firewall to the distributor cap was just that.
The sparking inside the original distributor creates ozone which is highly corrosive.
The vent tube bled it off.

 

[TheDurangoKidd]

The distributor is a tooth(s) off.

Thanks for confirming, this is what is suspected. I'll rotate it a tooth and report back.

.... or did you mean you were just trying to set it to the base timing?

Yes, this is what I meant.

The vent tube through the firewall to the distributor cap was just that.
The sparking inside the original distributor creates ozone which is highly corrosive.
The vent tube bled it off.

OSS If I pull the vent tube off of the connection at the firewall should I cap the piece going through the firewall? Currently I don't have access to the passenger side to see where that vent terminates. Thanks

 

[OSS]

Thanks for confirming, this is what is suspected. I'll rotate it a tooth and report back.



Yes, this is what I meant.



OSS If I pull the vent tube off of the connection at the firewall should I cap the piece going through the firewall? Currently I don't have access to the passenger side to see where that vent terminates. Thanks

It’s a little hole. Sure plug it up.

 

[TheDurangoKidd]

I'm posting my blunders in the hope someone will learn from my mistakes....

Sometimes you should leave well enough alone! It was running well but the "timing" numbers didn't match spec (I stabbed the dizzy 1 tooth off) and had the compulsion to fix this. As far as I can tell no harm would have come from running this way. Anyway, I pulled the dizzy and rotated it one tooth counterclockwise, started it and this time base timing was 29 degrees BTC. Not zero, not 18 like it was previously. Dang, I must of rotated it the wrong way. No problem, easy fix. Rotate it two teeth clockwise, problem should be solved! Nope, won't start at all. I rotate the dizzy one tooth counterclockwise to get back to where I started. Nope, won't start. Now I'm starting to get frustrated.

Walk away, take a break. try again tomorrow.

I've worked on this every day for the last 5 days.

I started by rotating 1 tooth at a time counterclockwise. I did this 16 times before throwing in the towel. It did start a few times, ran like crap once. On another occasion it backfired a bit through the carb (Sniper).

So this isn't working. Time to start over.

Pull the skidplate and flywheel cover. Set the motor at TDC with the mark on the flywheel. Stab the dizzy per the Toyota manual. Try to start and no luck. Rotate one tooth clockwise, no luck. Rotate 2 teeth counterclockwise, no luck.

Start over with finding TDC etc. and get the same results. It's about this time that it hits me that on my 4T dirt bike there is top dead center compression AND top dead center exhaust.

Pull the valve cover to check the rocker arms on piston 1 with the TDC mark on the flywheel lined up with the pointer and sure enough the rocker arms are tight as hell. aka open, not closed (which you need a sealed cylinder to have compression). Rotate the motor over 1 full rotation, line up the TDC mark on the flywheel with the pointer and this time the rocker arms on piston 1 are loose, valves are seated, cylinder is sealed. Re-stab the dizzy per the Toyota manual. She runs but has a high idle (850-1,000 rpm) and I can't get the timing mark visable in the sight window.... I buttoned her up to see how she drives (I can mess with the high Idle later). I couldn't get her to run well. She went from pinging to zero power with the slightest turn of the dizzy, back to the garage. And some quality time on Mud.

By this time I must have 10 tabs open on my browser all on Mud and all on DUI distributors. While rereading @residualboulders issues and troubleshooting in Davis DUI installation/evaluation - https://forum.ih8mud.com/threads/davis-dui-installation-evaluation.1230380/ I noticed @Steamer pic in post #43. Following my manual. Stabbing the dizzy starting with the rotor pointing toward cylinder 3 when seated it points BEHIND cylinder 4. The pic that Steamer shared shows it pointing IN FRONT of cylinder 4. I checked my manual. It has a section for "Distributor Installation FA & General FJ Series" and a section for "Distributor Installation USA FJ Series" While the pictures both show the distributor installed with the rotor pointing behind cylinder 4 the FA & General FJ Series says approx 30 degrees while the USA section says approx 22 degrees. And sure enough according to my fancy protractor 22 degrees is in front of cylinder 4. I had to start with the rotor pointing just to the front side of the #3 spark plug to get it to seat in the correct position. She still did not start right up, she wanted to, but wouldn't (a helper would have made this much easier). I just turned the dizzy ever so slightly and tried to resart untill I got the stongest attempt, then (against the Snipers instructions) I gave her some gas and she fired up.

Pulled and plugged the vacume advance and set the timing. I started at zero, verified the BB was at 7 and set final timing to 12. She's running but still with that anoying high idle. You probably know why, because I still have the valve cover off and didn't plug the breathers so I have a massive air leak. Reinstall everything. Idle comes down. Reset timing and all is good, well I still have to set the IAC on the Sniper...

I'm guessing that if I had plugged the breather or reinstalled the valve cover and all of its' bits she may have started a lot easier.

Oh and that heater hose that goes over the top of the valve cover that you took off to make getting the valve cover off easier, you better reconnect that before you try to start her unless you want to mop the floor with antifreeze.

1st pic is the rotor pointing just infront of #3 (I know it looks behind, it's the camera angle)

2nd pic is where you want the rotor to end up

If any of my assumptions are incorrect please correct me. I'm learning, slowly

 

[TheDurangoKidd]

Here is a blurry pic of where you DO NOT want the rotor to point and the above mentioned pages from my manual.

 

[BlackCat]

I bet it took me 40 times to get mine installed right. It seemed to always go in easily a tooth off, which is probably why someone installed it a tooth off. Minus the 180 out issue, I had the same troubles.
I feel like correctly installing a distributor is just as much a rite of passage as rebuilding the knuckles are.