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RunOpel
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809 Posts
Discussion Starter #1
Okay several of you recently have helped me with my timing issue concerning my timing light that has an advance setting.
Well here is my dilemma:

My new points that I got from OGTS and Gil's recommendation of setting the gap at .018 which I have done. Next I
removed the vacuum advance hose from the distributor and plugged it. The PO removed the vacuum retard hose from
the distributor, but plugged it on the carb. Gil says that is okay as most Opel owners remove the retard hose. Then I
connect my timing light and line the ball and pointer on the fly wheel. Problem is, I get the idle at 400 RPM and the engine
nearly shuts off. If I remove the timing light and time it by ear and tach RPM to 800-900, the car idles awesome. When I
drive it at 3000-4000 RPM, it runs great with no pinging or missing. When I re hook the timing light and check the timing,
to get the ball and pointer to line up, I have to advance the timing light setting to 19 degrees.

So what am I doing wrong or is my timing light messed up or is the carb not set properly?
Please HELP from any and all would be greatly appreciated :)
 

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Opel Rallier since 1977
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1,035 Posts
You are not doing anything wrong dpre. The BB & pointer lines up the timing at the stock factory timing. That can be at 0 or even slightly retarded, and as others have well said here, that was for emissions, not best performance.

So you are finding what the difference is between best performance timing and emissions timing! If you recall all the complaining and whining about crappy engine performance in the US starting in 1972 (and earlier in CA), then this is a big part of what that was all about.

BTW: One big difference in timing for peak idle RPM is a reflection of compression ratio. If you have the lower compression ratio stock pistons, then the timing will usually have to be more advanced for peak idle speed than for a higher compression ratio.

Personally, I don't ever quite advance timing to the peak idle speed. It can cause issues in surging in 1st gear. I back off a few degrees, so I'd be going for 15 -16 degrees myself. (AND for later discussion here, what you are measring is called 'initial timing'.)

AND, you need to make sure that your timing at the higher idle is not being partially effected by the mechanical advance coming in at your idle RPM. Do this:
  • Do this with the vacuum advance disconnected and plugged
  • Get up all warmed up, with your dial-back light adjusted with the BB lined up with the pointer
  • Nudge the throttle open a bit for maybe 100-300 RPM idle increase and watch the BB
  • If the mechanical advance is not yet coming in, then the BB will stay on the pointer (timing not changing)
  • If the BB immediately starts to move off the pointer when you start increasing RPM's, then the mechanical advance IS coming in right away, and it is starting to operate too soon. Mechanical advance being active at idle is another source of idle instability.
  • Finally, rev the engine to higher and higher RPM's to see where the advance stops increasing and record that maximum timing (which is the initial timing plus the maximum mechanical advance). You will have to go back and forth between throttle and dial-back setting to find this.
You want to find what the maximum total initial and maximum mechanical timing and keep it under control and typically limited to a maximum in the mid-30's range. The threads about limiting the mechanical advance with different stops on the weights is what this is all about.
 

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885 Posts
Glad your asking Dan,
I would like to put in the electronic ignition and would have done so already but all this discussion is greek to me right now as to timing and all that follows
I hope I can learn from this so I too can move forward with it.
Sounds like your already on the right road. I mean the fact you know how to use a timing light is great
I've only seen one used once in my life as luck would have it I wasn't paying attention that day
 

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RunOpel
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809 Posts
Discussion Starter #6
Thanks for the valued information to all. That makes total sense. I will follow up with your suggestions and report back. I do have the lower compression pistons and fortunately even with an original engine and mileage of 123,000 I have very good compression. The car runs very well at low or high RPM.
I was just unsure of the vacuum advance being so high. It actually even runs as well at 15-16 degree advance.
Thanks again for your time in helping me :)
 

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Just Some Dude in Jersey
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13,785 Posts
Glad your asking Dan,
I would like to put in the electronic ignition and would have done so already
FYI: If you get the new Pertronix III there is no difficult or iffy adjustment or parts to it. Put it on with one screw and you're done. I think only 2 wires to hook up. Unlike previous versions, it reads the 4 lobes on your dizzy's central shaft. It locks in to an existing post and the one screw you install, no adjustment needed.
 

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Opel Rallier since 1977
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1,035 Posts
And OP, I went back over my notes of what to measure, and realized that I should have said to disconnect and plug the vacuum advance when doing all of that. You want to measure the mechnical advance part without it being effected by the vacuum advance, so you can separate the different factors out. I revised my post to add that.

And while I agree that a dwell meter is best for setting points gap, if your distributor shaft is not wobbly, the gap method with a feeler gauge is quite satisfactory. I never had a dwell meter for racing...just set the points gap, Never any issue.
 

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RunOpel
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809 Posts
Discussion Starter #9
Thanks Manta Rallier 😄
Gordo I didn’t know there was a Pertronix III and even easier than the previous Pertonix. I have been wanting to change to that setup, maybe I should to simplify things.
 

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Über Genius
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8,748 Posts
If your centrifugal advance is gummed up you will never get where you want to be
 

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643 Posts
What I usually do is start at 3.500-4,000 RPM the timing should be all in by then. Set it up at 34° to 36° on your dial with the vacuum advance plugged off. Then drop it down to idle to see if the engine rpms are enough to keep the engine idling. If not go ahead and cheat the idle speed screw to bring it up to 900 rpms, see where the timing ends up at (probably somewhere from 0° to 4°). There, your timing is where it should be on the mechanical advance if you have a good distributor. If it’s gummed up like First Opel mentioned your reading at idle should be high. I had a gummed up dizzy on my 72’ 1.9 and it was 30° advanced at idle, it didn’t move much if at all so it was close 30° all the way through the rpm range. I had no idea because it was a low compression engine that hardly ever pinged. I did get kickback on the starter however.

What you can do with the type of timing light you have is start at idle speed then creep up to 3500 rpms 500rpms at a time and write down what your timing comes in at each time. If it comes in too fast you might have a missing spring, too slow or not at all it’s probably gummed up.
I just like to know where mine is at so I run this check when setting up a distributor.
The rough rule of thumb is after you get past 1,500 rpms or so the timing advancement number should be close to the rpms your at. You’re checking for consistency too.

I had a difficult time getting my idle speed up an I used an aluminum bushing to give me about 15° initial advance, @36° total @3200 rpms. That gave me the 900 rpms with the carburetor properly set up.

Ultimately be sure that the carburetor idle speed screw isn’t in more than 1.5 turns on the carburetor then adjust the mixture screw if needed. HTH
 

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Opel Rallier since 1977
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1,035 Posts
FWIW.. ch
Thanks Manta Rallier 😄
Gordo I didn’t know there was a Pertronix III and even easier than the previous Pertonix. I have been wanting to change to that setup, maybe I should to simplify things.
FWIW.. changing to a Pertronix III or any other ignition trigger does not change the timing, except for having to reset your initial timing setting. The mechanical and vacuum advance operations remain the same for thre Ignitor series of ignition modules.

Now if you change to a complete computer controlled ignition system that can be programmed from a computer or other device, then this all changes. But that is a whole 'nother level of cost.

Glad your asking Dan,
I would like to put in the electronic ignition and would have done so already but all this discussion is greek to me right now as to timing and all that follows
I hope I can learn from this so I too can move forward with it.
Sounds like your already on the right road. I mean the fact you know how to use a timing light is great
I've only seen one used once in my life as luck would have it I wasn't paying attention that day
ON the flip side, there is no reason to not change over to the electronic ignition at any time. If you are an HVAC guy, this ought to be easy for you to figure out.
 

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RunOpel
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809 Posts
Discussion Starter #13
Great advice to all :) I will start to play around with the recommendations and let you know what the results are. I'm pretty sure I don't have a gummed up distributor.There is no wobble what so ever. The engine is really pretty good with good compression. I know the PO had replaced the original Solex carb with a new Weber carb, but I haven't touched or checked any settings on the carb. It has always run well so I haven't wanted to mess with it and screw it up. It seems simple enough to check the idle and mixture settings though.

I'm very grateful to all of you who provided me with information. Thanks :)
 

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FWIW.. ch

FWIW.. changing to a Pertronix III or any other ignition trigger does not change the timing, except for having to reset your initial timing setting.
That's the part I'm going to have to learn. I have a hotspark # 3BOS4U1 that came with the car still in the box But the instructions to install it were a bit confusing to me
And to boot I've never messed with timing or distributors so I'm a little gun shy on that front.I also have an electric fuel pump in the box that came with it AUTOBEST #F4027 or E8016S
after reading post about adding relays for cut off and a regulator to control pressure I abandoned the idea and replace the manual pump
 

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What is it that is confusing ? You connect the red wire to +12V from the fuse box or some other source where there is current when the key is on, and the black wire connects to the negative side of the coil. But whatever you do, don't cross the wires, the module will burn. The coil should also have a primary resistance of at least 3 Ohms. No rocket science there.
 

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885 Posts
I get all of that, wiring isn't the issue, ohming stuff isn't an issue it's the whole timing thing ( reset timing to distributors factory setting ect.)
And the last thing I want to do is attempt this and have a crapping running car and not be able to drive tomorrow before the big game
My son and I always weather providing take the gt out on sundays for joy rides in the neighborhood
 

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Opel Rallier since 1977
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1,035 Posts
Hey Terry,

Go buy a simple timing gun and try it out. It'll be pretty easy to figure out and get the hang of that part.

But ya gotta disguise the purchase as something to use on the house's AC system.... "Hey honey, does the house feel cooler now to you? I was just changing the timing on the compressor and I want your opinion." LOL
 

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Registered
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885 Posts
Hey Terry,

Go buy a simple timing gun and try it out. It'll be pretty easy to figure out and get the hang of that part.

But ya gotta disguise the purchase as something to use on the house's AC system.... "Hey honey, does the house feel cooler now to you? I was just changing the timing on the compressor and I want your opinion." LOL
HAHHAHAHAHAHAHAHAHA GOOD ONE
Her reply ( all the years and you never had one)
my reply (No I always adjusted it with the system total charge) LOL
 
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