123 Install Today - GETTING CLOSER..., PROGRESS: BAD MPS Options

[VaccaRabite]

We need 33-39 degrees advance at high-speed full load. This number is dependent on cylinder head design and the use of quench. The more efficient the engine the less total advance we need. Super common is the number 37...
I believe this is the red mark on most of the fans on T4s that you adjust timing too at 3K rpm. They're having you set MAX timing at MAX load this way. Don't the instructions tell you to disconnect vacuum hoses and plug?

@technicalninja

The red line is set for 27*, not 37* on a stock system.
Its common for carbs to go up to 32* I think that's where I have my 2.3 timed.
By 37* you are likely over advanced.

But stock for a 1.7 or 2.0 is 27* #3000 RPM.

Zach

[technicalninja]

We need 33-39 degrees advance at high-speed full load. This number is dependent on cylinder head design and the use of quench. The more efficient the engine the less total advance we need. Super common is the number 37...
I believe this is the red mark on most of the fans on T4s that you adjust timing too at 3K rpm. They're having you set MAX timing at MAX load this way. Don't the instructions tell you to disconnect vacuum hoses and plug?

@technicalninja

The red line is set for 27*, not 37* on a stock system.
Its common for carbs to go up to 32* I think that's where I have my 2.3 timed.
By 37* you are likely over advanced.

But stock for a 1.7 or 2.0 is 27* #3000 RPM.

Zach

I stand corrected. Thanks, VaccaRabite!

Just verified I'm not spouting trash regarding ignition requirements.
I'm not, those advance numbers are correct for water cooled stuff.

Air cooled stuff is sometimes different in ways that I didn't expect.

I apologize if I overstepped...

I do believe I answered the intitial questions that started this thread!

[FlacaProductions]

Now if you could just get my car to start.... (IMG:style_emoticons/default/shades.gif)

[technicalninja]

Just re-read everything.
@iankarr advice is spot on. Disco/plug vaccum, put in simple base map, make sure it runs.
Perfect progression.

Another tip that has caused me grief with diag before is "make sure your spark plugs aren't fouled"...

Many of your posts sounded like either misfire or "not in correct firing order" problems.

Many of the other posters picked up on this.

Pull all plugs, inspect, clean.
While plugs are out verify TDC on #1 via the finger/tube method. Check flywheel mark to fan mark correlation.

With engine on TDC #1 look at which cap tower distributor rotor is pointing at. Make sure this goes to #1. Do the green light test/adjustment at this point.

Install plugs/wires. Get the direction of rotation, timing order, and cylinder layout correct. The T4 has a normal firing order and a strange cylinder # scheme to me.
Most manufactures number odd on one bank and even on the other with the rod journal position on the crank determining cylinder number.
The T4 is not this way.

Try to start. Still not friendly?

First, I'd remove the cap/wires from the distributor, pull it from the engine with the primary wiring still connected. Take the coil wire out of the cap and affix it 3/8" away from engine ground.

ATTACH GROUND JUMPER BETWEEN THE DISTRIBUTOR HOUSING AND THE ENGINE.

This is in CAPS as there is a chance you might fry the circuits and chips inside the distributor if the housing is not grounded properly.

Now the distributor is free of the engine, still hooked up to the primary circuit, properly grounded, and in your hands...
Turn ignition switch to ON.
Spin it from the drive gear and watch what the coil wire does. It should rain fire. The sparks should be blue and distinct, it should "crackle and pop" with each spark.
If yellow and soft you have either a bad coil, bad ignitor unit (inside 123), or restricted primary voltage (check this with a DVOM at coil +).

Still screwing up after the above? Put the old points distributor back in it, make it run properly and go drive it 10-20 miles to clean heads/tops of pistons.
"Blow it out" under load! (this stage is often FUN!)

I'd speak with Ed if the old distributor makes the car run and the new one does not.

[FlacaProductions]

(IMG:style_emoticons/default/agree.gif)

[123ignitionusa]

A car will run on it's old points distributor and not on a new 123ignition if there is too much resistance in the primary circuit. It could show 12v at the coil but not be a clean 12. Even old ignition switches, fuse blocks, starter posts and junction boxes can build up resistance. Old cars and bad grounds are notorious for having problems. I will mention that spark plugs are often the culprit. Today even new is no guarantee.

Hope this helps
Ed

[FlacaProductions]

One thing that you mentioned to me, Ed was to disconnect everything from the coil, run a line direct from + side of the battery to the + side of the coil and then connect the red from the 123 to the + at the coil and the black from the 123 to - at the coil. Connect the blue wire from 123 to ground.

This circumvents the primary circuit and if it fires in this configuration, indicates too much resistance in the primary.

It's on the list - didn't do it originally as I always felt I was "this close" by doing the standard setup.

[technicalninja]

One thing that you mentioned to me, Ed was to disconnect everything from the coil, run a line direct from + side of the battery to the + side of the coil and then connect the red from the 123 to the + at the coil and the black from the 123 to - at the coil. Connect the blue wire from 123 to ground.

This circumvents the primary circuit and if it fires in this configuration, indicates too much resistance in the primary.

It's on the list - didn't do it originally as I always felt I was "this close" by doing the standard setup.

I'm confused!
That's how the 123 is wired per their instructions.

I'm thinking, wired up this way and rotation of shaft SHOULD make sparks.

Ed's response brings up "the old car syndrome" and he's right. What is the condition for the main feeds and grounds? I'll add an "instant" ground with the negative side of a pair of jumper cables to check if that helps.

I'm planning on a new coil with correct internal resistance at install with mine.


Have you changed the coil?

[FlacaProductions]

The difference is that the way I described takes the ignition switch, etc. out of the equation.

My main feed and grounds are in good shape. For example, I get no movement on the voltmeter when turning on my lights, etc.

I've tried two coils: new one from 123 as well as a very new one from Pertronix that I was previously using without issue.

[914_teener]

The difference is that the way I described takes the ignition switch, etc. out of the equation.

My main feed and grounds are in good shape. For example, I get no movement on the voltmeter when turning on my lights, etc.

I've tried two coils: new one from 123 as well as a very new one from Pertronix that I was previously using without issue.

That's not an example of a proper electrical check; they aren't on the same circuit and the more you don't test anything the more confusion you'll be in. Take the time to do what you are asking advice for.

Here is a link to the wiring diagram; http://914world.com/bbs2/index.php?showtopic=331099

Learn to read it. There could be a bad trace on your regulator or copper trace circuit board. Also, as Ed has suggested...if your ignition switch is old...you may be getting intermittent contact and since you installed it incorrectly the first time it could have arced the contacts on the switch.

Node number 6 is the coil and as you can see it's from the yellow wire for the primary feed which goes through the regulator plate. To do a resistance check, you would need to test the resistance across the trace. You could have 12 volts testing it without a load but when you turn the key...maybe just intermittently when the trace heats up. Have had it happen to me.

You need to be methodical when testing and not wishful....or magical thinking...sorry but that's been my experience. Electrical issues are usually the most challenging and one needs to have or take time to diagnose them properly.

Good luck and Godspeed.

[FlacaProductions]

Welp - I'm going to pretty much stop right here because I can't do anything about it for a number of weeks and there are a lot of things already on a list for me to check when I DO get back at it.

I'll be slow, methodical and precise and will report in.

HUGE thanks for all the tips, suggestions and pointers offered up. Hopefully, after this is resolved this thread will be of help to others.

[FlacaProductions]

Well - after reading this thread, I'm not in the best frame of mind.
Still a few weeks away from getting back to it but first thing is going to be pulling the valve covers and checking for damage...

http://www.914world.com/bbs2/index.php?sho...=369548&hl=

[VaccaRabite]

I've been following that thread too.
His issues are his issues, and yours are yours. In his case there is mechanical damage. Do not assume that is your issue as well until you have reason to think so. Far more likely to just be tuning.

And, really, pulling the valve covers and looking takes 30 minutes, and get you into position to do many of the other checks we suggested in the Fall.

Chin up camera man!

Zach

[FlacaProductions]

Ok, Zach - you're right. Too much idle time and letting my brain drift to worst-case-scenario....thanks!

[emerygt350]

At least worst case on these motors isn't the same league as worst case on a 6 cylinder.

One thing all of these threads have gotten me thinking about is timing accuracy. How much it matters, how precise can we be, how much we can believe in our precision. It's supposed to be warm tomorrow and I am planning on locating my flywheel mark and checking it against my fan. I replaced my fan with an unmarked version in the rebuild and painted it, but that ended up being a pretty broad stroke...

And it's not to know what the right timing is, that is specific to my build, it's for comparison. I can tune my engine to what it wants, but if my marks are not right I can't say that my engine wants 30 degrees.

[914_teener]

Ok, Zach - you're right. Too much idle time and letting my brain drift to worst-case-scenario....thanks!

The whole point about the Anders site for troubleshooting a D-jet injection system is making sure or put another way, "confidence" that ALL mechanical systems are correct first, or put together correctly and the parts associated with the D-jet system for the model year and displacement are working and correct for that displacement.

Had the OP of that thread simply pulled the valve covers off to make sure the valve lash was to spec....he wouldn't have wasted his time trying to set the timing.

Besides the fact that the dizzy doesn't look like a stock distributor or has been altered.

See point No. 2.


Confidence in what one is doing is also very relevant if not essential to troubleshooting. Mostly confidence is bolstered by experience.

My greatest learning experiences have been by doing and making mistakes.

[FlacaProductions]

Ok, folks - back at it today.
Progress. Sometimes it's best to back out and take a fresh run.
I did a fresh install - this time after CONFIRMING TDC by taking a close look at the marks thru the bottom of the trans and then correlating this with valves after popping the left cover off. Dave D's point about making sure there's slack in both of the #1 valves was key. That - coupled with the white TDC mark on the fan lining up in the notch AND the correct orientation of the distributor drive slot sealed it.

I couldn't do the final, final confirmation by checking for the TDC notch on the top of the flywheel as I have my charcoal canister kinda in the way but fan mark, rotor position, drive slot, valve state and tranny inspection hole marks (three dots made by Brad Mayeur when he built this motor...) lined it all up.

dropped in the 123, did the green light spin, hooked all wires up - making certain firing order was right for the plug wires - and it fired up smoothly.

Had to stop for the day but it is NIGHT and DAY from the last time.
Tomorrow will be the final timing and set up but I'm more confident than I was, that's for sure.

Only bummer of the day is the new billet aluminum distributor hold down clamp is really nice but is too thick to get a nut on with any bite. Strange...but overall, success.

More soon....thanks to all - I REALLY appreciate all the input.

[emerygt350]

Good to hear it!

[Stratfink]

That is GREAT news Brian. So glad it fired up and looking forward to hearing how it goes getting everything dialed in tomorrow.

Joe

[FlacaProductions]

OK. BIG revelation.
Turns out my MPS appears to have gone bad somewhere along this process.
I had tested it when tracking down my running-warm situation and it held vacuum fine.

Meantime - just last week - I picked up an 043 MPS that I saw on ebay for a good price. Just to have as a spare - and because my 041 had been adjusted/installed previous to me.

So today, I got back to timing the 123 and it just wouldn't hold a constant rpm no matter what I did. Would start, idle somewhat ok but i couldn't get it over 2000.

So - on a total whim, I threw in the new 043 and it's like night and day. amazing difference. I'm pretty happy right now.

I'm wondering if my 041 bought it due to one of the backfires during my initial 123.

But anyway - wow. Hopefully will have this buttoned up today.