Timing Retard

[opelbits]

Yep, that's me!


Anyway, I was wondering what thoughts experienced people might have with disconnecting the vacuum retard from the distributor. I'm running the 2.0E with a stock 74 distributor (stock except for the Pertronix).
I have some 'oddness' with my idle that seems to go away with the retard disconnected. I have eliminated every vacuum leak I have found and the vacuum advance/retard diaphragms hold vacuum just fine.

Are there any ill effects to running without the retard?

[tekenaar]

Originally Posted by opelbits Yep, that's me! Anyway, I was wondering what thoughts experienced people might have with disconnecting the vacuum retard from the distributor. I'm running the 2.0E with a stock 74 distributor (stock except for the Pertronix). I have some 'oddness' with my idle that seems to go away with the retard disconnected. I have eliminated every vacuum leak I have found and the vacuum advance/retard diaphragms hold vacuum just fine. Are there any ill effects to running without the retard?

In a word, NONE! The vacuum retard is only active at idle and is strictly an anti-pollution device, so you're perfectly fine leaving it disconnected. I would disconnect and just tune your disti again without it . . . probably no adjustment required, since you're supposed to set the disti initial timing with no vacuum hoses attached in the first place!

[Paul]

As Otto states, the vacuum pod activates at High mainifold vacuum such as idle. Also it retards the timing any time the throttle is closed such as when lifting off the gas beteen gear changes or when you depress the clutch when coming to a stop. Therefore it does help the idle settle back down to the idle rpm a little quicker. If, after disconnecting it, you find a small change with the engine returning to idle as quickly as before, then you'll know what caused it.

BTW, I've had the diaphram in the vacuum pod leak and cause the same roughness you describe...

Advancing initial timing to 5 degrees should have the same effect as unhooking the vacuum pod.

[opelbits]

I feel like I am in BizarroWorld.

The other night I retimed everything from scratch. Set initial timing with vacuum disconnected. Used a vacuum pump to check actuation of retard and advance mechanisms. Hooked up retard and rechecked timing....it retarded 5 degrees. Hooked up advance, revved motor and it advanced just as it should. Even checked the mechanical advance. Everything seems to work as it should. Readjusted carb, adjusting screws are more sensitive than they have ever been.
Nice idle, plenty of power. 16" of vacuum at about 8-900rpm. Took it for a drive. Plenty of power, revs easier and better than ever. Park it and let it idle. Idle drops to about 600 and is rough.
Disconnected retard and idle comes up and smooths out a bit.

Today....disconnect retard and get no real change. Went to hook up vacuum gauge to manifold fitting while engine was running. Pull off vacuum cap and instead of the car wanting to die.....it smooths out real nice.
My car should not idle better with a big vacuum leak! It's can't be running rich enough for the leak to improve the idle.

On the road it runs good, though. With out the vacuum leak of course.

[tekenaar]

32/36 or Solex? If 32/36, what's jetting in it now?

[opelbits]

32/36
Couldn't tell you exactly what the jets are, but I had gone thru many posts here about jetting and I believe I currently have jets appropriate (according to the posts) to a relatively stock 2.0.

[tekenaar]

Originally Posted by opelbits I feel like I am in BizarroWorld. The other night I retimed everything from scratch. . . . Disconnected retard and idle comes up and smooths out a bit. Today.... Pull off vacuum cap and instead of the car wanting to die.....it smooths out real nice. My car should not idle better with a big vacuum leak! It's can't be running rich enough for the leak to improve the idle. On the road it runs good, though. With out the vacuum leak of course. Originally Posted by opelbits 32/36 Couldn't tell you exactly what the jets are, but I had gone thru many posts here about jetting and I believe I currently have jets appropriate (according to the posts) to a relatively stock 2.0.

. . . your primary main and/or idle jet is probably a tad too rich . . . idle smoothes out when you add air. Need to look at primary main/air corrector ratio first, then at idle jet. That's my take on it anyway . . . overly rich primary mixture will affect idle more (more noticeable) than higher speed operation.

[opelbits]

I'll have a look at them tomorrow.
Thanks-
Tony P.

[opelbits]

Okay, here is what is currently in the carb:

Main jets:
Primary 40
Secondary 142

Idle Jets:
Primary 60
Secondary 50

Air Corrector Jets:
Primary 165
Secondary 160

Emulsion Tubes:
Primary F50
Secondary F6

Idle Mixture 3 turns
Idle speed 1 1/2 turns


I may have changed some stuff as I don't recall what the suggested jets for the 2.0 were. It's been a year or two since I really got involved in this.

Currently I am running a stock GT exhaust. I have not yet fabricated a 2-2 1/4" system.

[jvandyke]

I also had some idle issues, a notable stumble every couple seconds. Also occasionally after decelerating idle would drop way low and sometimes stall the engine, sometimes slowly return to normal. This was becoming problematic.
Long story short: plugging off the idle retard line (at both the dist. and the manifold) removed the stumble and so far no severe idle drop.
2.0E with distributor of unknown year (not 75 as it has advance and retard).
I'm convinced (finally) that it isn't carb related as it was happening with my Holley/Weber 32/36 and the Weber 38 I'm trying to swap to.
I'm going to run with the retard disabled for a while as I struggle mightily to get the 38 issues ironed out.

[jvandyke]

I'm still running with retard disabled, just wondering if the line from the canistor being plugged might restrict the operation of the vacuum advance end of things? Not sure about the innards of these things. Mine just seems quite resistant. I can't imagine manifold pressure being enough to move it. Breaker plates were all apart, cleaned and lubed.

[opelbits]

The manifold vacuum is pretty strong. I recently replaced a section of my brake booster hose with some heater hose (just temporarily, you see). Anyway, when I started the car the heater hose was completely and absolutely flat.

It takes a bit to move the advance, but the vacuum produced by the engine is more than enough.