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-   -   How can you check timing if you can't warm engine up? (http://forums.pelicanparts.com/porsche-911-technical-forum/343858-how-can-you-check-timing-if-you-cant-warm-engine-up.html)

rs6er 04-29-2007 12:24 PM

How can you check timing if you can't warm engine up?
 
I am having a missfire that seems as if I am running on 5 cylinders. I have checked wires, plugs, dist cap and rotor. They are all good and fairly new. I want to check the timing at idle, but the Bentley says the car must be at operating temperture to check the timing. Also, I have a timing light but have not used it for years and never on this car. Where do you attach the red lead in the engine compartment? I assume you connect the black to ground. Where do I connect the other wire? I know this is really basic stuff, but I'd appreciate a Timing 101. PS I have all the info on the advance etc. Also, the car was running fine until recently.

rs6er 04-29-2007 12:44 PM

OK. The Wayne's book has answered my questions about connecting the timing light. What about getting the motor warm when it doesnt want to run?

Gogar 04-29-2007 12:57 PM

You can check it cold to see if you're even close. Get it as good as you can cold, just don't check the high-RPM timing until the engine is warm.

Eagledriver 04-29-2007 01:13 PM

You may be able to identify the cylinder that is not firing with the timing light. Put the inductive pick up on each sparkplug lead in turn to see if you find one that will not flash the light. Even if they all work you could have a fouled plug but at least you might learn which one this way.

-Andy

rs6er 04-29-2007 01:52 PM

I finally got it running and warmed up. One of the things I did which smoothened out the idle was to switch the vacuum lines on the distributor. I was cleaning them recently and may have put them back wrong. I had the blue one on the right and the red one on the left. When I switched them, it idled much smoother. Now I can drive, but the motor is still not running smoothly. I checked all the plugs except #1 because it is kind of hard to get to with the backdated heater duct. I also bought a tool at Sears which shows if you have spark by resting its concave surface on each wire. There is definitely spark in each wire. I couldn't get my old timing light to flash. Not sure if it is caput or not. I'm going to clean all the copper clamps and try again. Does it matter which fuse you attached the red lead to?

Gogar 04-29-2007 02:13 PM

No it doesn't matter. You might want to take a Volt Meter and make sure you've got 12v at whatever one you're using, just in case. The top red one is for the Heater Blower. Since you've got backdated heat, maybe there's no 12v there for some reason.

rs6er 04-29-2007 02:27 PM

The inside of the cover says the top one is for a Sportomatic. There is no fuse there. Just the middle and bottom. Any thoughts on the vacuum hoses? Are red and blue bubber hoses standard?

911pcars 04-30-2007 11:16 AM

Does it still misfire? The static ignition timing would have to be way off for that to happen. It's something else.

Or do you just want to connect the timing light?

Sherwood

rs6er 04-30-2007 11:32 AM

Thanks. The car is on a trailer on the way to my mechanic now. I'll share what was causing the misfire when I know what the problem was.

stlrj 04-30-2007 11:52 AM

Quote:

I have checked wires, plugs, dist cap and rotor. They are all good and fairly new.
Visual means nothing when it comes to ignition components. About the only thing that you can tell visually is if you pull your spark plugs, one might look sooty black which will identify which cylinder is missing.

Also, an ignition miss has little to do with ignition timing.

Joe


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