New wires, cap and rotor = No Start = HELP!

[Tom '74 911]

Hi & Help!
I just finished intsalling a new rotor, cap and wires and now my car won't start. I think it's a no spark issue (DUH!) The first thing I did was to put the old cap, rotor and wires back on and it still wouldn't start. I feel like it should be something so simple, but I'm to blinded by frustration at the moment to figure it out.

When I try to start it:
I hear the fuel pump as usual
The engine turns over
But does not fire

It's almost like there's a kill switch (I do not have one installed). Old wires or new wires - no Joy - which makes me sad.

Other things I was doing at the same time as new cap, rotor and wires:
Checking valve adjustment
Bleeding brakes
Messing w/my headlight trim rings (I think this is the cause!)
I did tape a wire inside the distributor that had rubbed a bit
The rev limit piece of my rotor had broken off - thus the replacement see this thread

What could I have unplugged and am forgetting? I have checked the plug wires 10 times to make sure they are plugged in correctly and in the right order. I'm not sure how to check the coil (I did some searching but am an electrical novice) and checking for spark scares me! - but may be my next step.

HELP!

Thanks,
Tom

[BlueSideUp]

I had a lot of great help from Grady Clay and others in this thread. No start condition

[unclebilly]

Did you happen to put Dielectric grease in your plug leads?

I had a similar problem with my C4 this morning until I cleaned the dielectric grease out of the plug boots.

[JP911]

Is the cap seated all the way on the distributor? This same thing happened to me once and it turned out that the cap was slightly rotated and raised up. When I re-seated it the car fired right up. The other thing to double check is that you are following the correct firing order on the distributor cap. I also had this issue. I followed the order as shown on the factory sticker in the engine compartment...which happened to be from an SC rather than a 2.7. To clarify, the order is the same but the SC dizzy spins counterclockwise.

[Tom '74 911]

First off - thanks for the responses so far. I appreciate the help. The knowledgable people here on the forum must roll their eyes every time a post like this comes up - which is a lot!

Some time away from my car (usually the best way for me to troubleshoot things is to just walk away!), some more searching here, and the responses above have given me at least a place to start and a few things to check.

I'll be back - hopefully having started it up - trying to thing positively!

Thanks,
Tom

[Rot 911]

I would double check the wire in the distributor that you taped up to make sure you didn't pull something loose.

[Tom '74 911]

Well, I've checked everything I can think of and no luck. I did succeed in popping a fuse though. I was going to check for spark by pulling a spark plug wire, inserting a spare plug and holding it to the case while my better half gave the key a quick turn. I didn't get that far as I popped the 25A fuse at the top of the fuse box as I was getting ready. The plug wire must have brushed it or come close to it. Is that normal? That goes to show how much I DON'T know about the electrical system.

Anyway, I'm about ready to give up and tow the thing 2.5 hrs. to the nearest shop I trust. Before I do, here's the electrical system troubleshooting equipment I have - plus a circuit tester light:



Are there any tests I can do - without endangering myself - that may help narrow things down?

Sorry to be such a dumas.

Thanks,
Tom

[JP911]

Did you end up checking for spark? That's the first test I would do. Actually, I would do two spark tests: spark at the coil and spark at the plugs. This will help to narrow things down. If you've got spark (at coil and plugs) and fuel, then you've still got something amiss with the firing order. If you've got spark at the coil and not at the plugs then something is up with your distributor.

[Tom '74 911]

Thanks JP -

OK - How do I check for spark at the coil?
and then,
How do I check for spark at the plugs?

Thanks,
Tom

[Tom '74 911]

morning bump

[Walter_Middie]

Tom,

To verify which way your distributor turns, put the trans in 5th and push the car forward while watching the rotor turn. I'd pull the cap, turn the engine until your are at TDC, then verify that the rotor is pointing at the position for the #1 spark plug. Then check the position of the wires from there. It's possible that the distributor was not installed correctly, and that plug wire #1 wasn't in the position you thought when you removed your old wires.

[emac]

Tom

It sounds you knocked your points closed when you were replacing the rotor. That would be the first place I would check.

[Tom '74 911]

Originally posted by Walter_Middie
Tom,

To verify which way your distributor turns, put the trans in 5th and push the car forward while watching the rotor turn. I'd pull the cap, turn the engine until your are at TDC, then verify that the rotor is pointing at the position for the #1 spark plug. Then check the position of the wires from there. It's possible that the distributor was not installed correctly, and that plug wire #1 wasn't in the position you thought when you removed your old wires.

Hi Walter,
I've adjusted my valves a few times and seen the distrubutor turn clockwise when I crank the engine at the fan pulley - I'm assuming it's the same when the engine is running. I've checked the wire positions and order a dozen times, but I will do it again to be sure. The cap seemed to only go on one way - I tried to put it on rotated 180 degrees and it wouldn't snap on - the grooves are different at each end. To be clear - I didn't remove the distributor itself, just the cap and rotor.

Thanks,
Tom

[Tom '74 911]

Originally posted by emac
Tom

It sounds you knocked your points closed when you were replacing the rotor. That would be the first place I would check.

Hi Ernie -
My distributor has been converted from points to Pertronix electronic ignition - so no points to mess with any more.
Thanks,
Tom

[Gunter]

Tom:
Do you have the original Bosch 3-pin CDI module?

Or some Permatune junk?

Checking for spark on the coil or plugs is not hard.
Do a search here, lots of info.

I remember seeing some taped wires near the distributor on your other thread. Can you post a picture of the rest of your ignition system?

Like around the distributor and the module?

[Tom '74 911]

Originally posted by Gunter
Tom:
Do you have the original Bosch 3-pin CDI module?

Or some Permatune junk?

Checking for spark on the coil or plugs is not hard.
Do a search here, lots of info.

I remember seeing some taped wires near the distributor on your other thread. Can you post a picture of the rest of your ignition system?

Like around the distributor and the module?

Hi Gunter -
I have the original Bosh CDI.
I will search some more about checking for spark.
There are quite a few taped wires in that vicinity! I will get photo-happy tonight and post some images of the ignition system and surrounding area.

Thanks,
Tom

[Tom '74 911]

Hi -
One more question - the new plug wires that I installed (OEM style Beru 10-8533-613-M47) were slightly different than the old ones (at the spark plug end). I double checked (twice) that I ordered the correct wires, and as far as the parts catalog numbers are concerned I did. Could the wrong plug wires short something out or otherwise wreak havock?
Thanks,
Tom

[Zeke]

Not really. Plug wires can make a difference, but usually not between whether the car runs or not. Since I've made this mistake more than once, make sure your brown and green wires are connected at the distributor. The black/purple (if you have one) is for the tach. It won't keep the car from running. Pelican has wiring diagrams up on the site.

[Tom '74 911]

Hi -
I did some more troubleshooting tonight and here's what I found:

1. I have no spark. Not at the plugs or the coil.
2. I disconnected everything from the coil and here's the readings I got:
Primary (btwn + terminal and - terminal) = 0 Ohms
Secondary (btwn + terminal and center) = 8.8 Ohms
I don't know what these mean - just hoping they will help in the diagnosis! BTW, I'm not convinced the coil is bad yet.
3. I don't think there is power to the coil - With the ignition in the "ON" position (fuel pump running, but engine not cranking) I checked the + terminal of the coil to a ground point and got a reading of 0 V.
4. The wire to the + terminal of the coil is not in the best of shape, but worked fine before my "new cap, rotor and plug wires" experiment.
5. I looked through the elect. diagrams and it looks like the coil gets it's power from the CDI unit? And the CDI unit gets power from the top fuse (of 3) of the rear engine compartment fuse box? Which gets power from the 14 pin connector?
6. The top fuse has 12V - ignition on or off.
7. So power isn't getting from the fuse box through the CDI, to the coil? Is there a way to hot wire the coil to find out if it's functioning?
8. I'm making this up as I go along, so I could be dead wrong!

Here's some photos - the first shows the condition of the wire attached to the + terminal of the coil - that does NOT read 12V w/the ignition turned on. I've also labeled the plug wires in the distributor (though there's no spark at the moment). The second photo shows the fuse that's hot, and some slight melting at one of the relay terminals?

Thanks for the help,
Tom

[Tom '74 911]

So now is my next step to try to figure out if my CDI is working?

morning bump