Ignition timing 180 out?

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Ignition timing 180 out?

Postby tgulden on Mon May 04, 2009 5:26 pm

I am having timing issues with my 81 FI Spider 2000 and after reading the various related posts, I remain puzzled. Here are my puzzlements:

1) When I hook up a timing light to the wires for cylinders 1 or 4, the timing mark on the crankshaft pulley appears to be 180 degrees out -- that is to say it is over on the right (drivers right) side of the engine bay, where it is very hard to see. On wires 2 and 3, it is more or less over where I expected it to be -- near the yellow timing cover on the drivers left side of the crankshaft pulley.

2) There are no timing marks on said timing cover! I know they can be hard to see -- but I swear I have used a really good light, cleaned the cover till it sparkles, and examined it very closely. The only thing molded into the plastic in that area is a very small (about 10pt font) number: "4027" -- which is raised and upside down (so you read it right side up while peering down at it). My Brooklands shop manual has a drawing of where the marks should be -- but I swear that they just ain't there.

3) I don't seem to be getting proper advance. I get a bit of advance (perhaps 10 degrees) between 700 and about 1500 rpm, but then things are quite steady upward from there. When I disconnect the vacuum line from the vacuum advance module, it behaves just the same way. I can feel suction at the end of the vacuum line when I rev. Does that necessarily indicate a bad vacuum advance, or are there other things I should check first?

This is in the context of a distributor that has had a bad inner seal for several months. I have the new seal, but have yet to get the dang pin out of the dizzy shaft. I think I will have to have a shop press it out -- no amount of hammering on a punch has been able to budge it.

Given 1 and 3, you would think the thing would run badly -- but it actually runs pretty well. It is getting lousy mileage (like 19 or 20 mpg), and the tailpipe is sooty -- but top speed is still 100mph+ and it feels good to drive. I'd love to find more horsepower in there with everything working right, but its not bad as it is.
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Re: Ignition timing 180 out?

Postby rlux4 on Mon May 04, 2009 6:30 pm

The later FI cars don't have the timing mark on the cover any more. There should be a pointer attached to the front of the block with 3 points on it and a circular hole behind them. This pointer should be right above the crank pulley.
The car will absolutely not run if it's 180° out. It will run, though poorly if it's not at the correct timing.
You can check to see if your vacuum advance module is bad by taking off the vacuum hose at the manifold end and sucking on it, if your module is good, the arm that goes into the distributor should move.
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'82 2000 Spider: after 26 years between Spiders.
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Re: Ignition timing 180 out?

Postby jfrawley on Mon May 04, 2009 9:10 pm

When I was first timing my '82, I could not shine the timing light on the pointer. The T-stat was right in the way. No amount of moving stuff around would do it. I finally got a mirror and put it down behind the T-stat at an angle, shined the timing light off it, and read the marks in the mirror. Sounds studpid I know, but I just couldn't see it any other way.
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Re: Ignition timing 180 out?

Postby manoa matt on Mon May 04, 2009 9:58 pm

Like Ron said, there is a metal pointer on the passenger side of the motor, which is where you want to point your light.

Its possible the springs on the advance weights are worn out. That would let the timing advance to its full advance at a lower RPM than it should. Or the bottom of the rotor is inhibiting the weights from flying out.

Those pins can be a PITA to get out. Usually there is one side that looks mushroomed over and the other end is a bit thinner. Make sure you drive it out from the thin end. If you bang away on it with a big punch then you can mushroom over the thin end and that will prevent the pin from ever comming out. When all else fails you have to grind off the end of the pin untill it is flush with the cam gear then drive it out. I've seen the solid pins replaced with roll pins.
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Re: Ignition timing 180 out?

Postby tgulden on Tue May 05, 2009 10:31 am

Sure enough! There it is, way down under all the belts and stuff. Who knew? Not the authors of the shop manual, apparently.

While we are at it, the shop manual has conflicting information about the proper timing for this engine. Its either 10° BTDC, or 0°. The text claims that pre '79 is 10° and '79 on is 0° -- but includes a table stating the reverse. IAP says all Spiders are 10°. Anyone know the truth for a 1981 FI 2000?

My vacuum advance module is definitely bad -- sucking on the vacuum tube produces no motion at the distributor and produces lots of airflow through the tube. The tube is good because if I pull it off the dizzy and put my finger on the end, the airflow stops.

So... looks like I have a better power curve coming! w00t! Its already much better with the base timing set right.

I have to admit that I first went after the pin with the wrong punch (technically, it was a nail set -- my background is in wood). I'll take another shot with the right punch before I give up and take it to somebody who actually knows something about metal.
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Re: Ignition timing 180 out?

Postby So Cal Mark on Tue May 05, 2009 2:33 pm

set the initial timing at 10btdc
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Re: Ignition timing 180 out?

Postby JB on Sat May 16, 2009 11:02 pm

I want to get some clarification on this. When replacing the belt and lining everything up the main crank shaft should be set to TDC with everything else on it's mark correct?? And then when setting timing with the distributer timing should be retarded to 10 degrees BTDC. Is that correct? Secondly I have removed the timing belt cover so what is the best way to know what 10 degrees BTDC is?
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Re: Ignition timing 180 out?

Postby kilrwail on Sun May 17, 2009 6:17 am

That would be "advanced" to 10 degrees Before TDC. I don't know for sure, but I don't think there's mark on the block that corresponds to the mark on the timing belt cover. But 10 degrees is about 2 minutes on a clockface (10/360 x 60), to the left.
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Re: Ignition timing 180 out?

Postby Hvnfn on Mon Jun 15, 2009 4:01 pm

Honestly though, folks... don't you care more about total timing at 35 degrees at 3K RPM? Why should I care a whole lot about the 10 degrees at TDC other than setting correct idle speed?
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Re: Ignition timing 180 out?

Postby So Cal Mark on Mon Jun 15, 2009 8:42 pm

you should care alot about more than total timing. For instance, if you're not getting enough advance then you will end up with most of the advance at initial timing. That can cause slow cranking, and detonation.
Mark Allison
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