Spark Plug & Tach job results in no-start

[boyt911sc]

Originally Posted by EricAlborg

Rotated all plug wires on the distributor cab, by one clockwise. Still, no joy. And I got a VERY LOUD backfire to boot.

The picture below wasn't very helpful, but this shows the plug wires and the firing order (which I'm sure you all know).



This begs the question of whether something I did with the tach was amiss. Or whether maybe the car is set up for different timing.

Eric,

Before you go crazy finding what's wrong with the car, check these first:
1). Check for ignition sparks. Remove one of the spark plug connector and use a known good spark plug for the test. Ground the spark plug to a good ground source. Turn the ignition switch with the help of an assistance and closely observe the ignition sparks color. Look for a bright blue color which means good and strong. Yellowish is weak.

2). If there is no spark, check for power going to the primary connector (@15) at the ignition coil. Turn the ignition switch and read the voltage (use a voltmeter).

3). If there is no spark, no power, check the ignition coil fuse.

There will be more but check them first. And keep us posted.

Tony

[EricAlborg]

Thank you, Tony, et al.

Unfortunately, I cannot bring the Porsche to thanksgiving on the mainland. I will report back when I return.

Happy Turkey day all.

[Flat Six]

Eric, did you ever get this sorted out?

[Bob Kontak]

Your number one should be closer to the mark I placed in your second pic.

Look at the pic of the 84 911 with blue wires. If you follow the wires you can see (and with a little assuming) that number one (blue wire) is close to where your first pic had the number one wire on (before rotation one terminal clockwise)

However, your first pic has number one in a far too advanced position (like on tooth) from where it normally resides.

boyt911SC is giving good advice. The number one terminal is in a pretty static position relative to the fan shroud on the 3.2 or the SC which spins in reverse. I think you are one tooth off but not sure.

What we don't have is a pic of your distributor that shows the fan shroud. That would allow better scrutiny.

Here is yours with my marks:



Here is the blue wire 84:



Here is an SC:

[Bob Kontak]

Originally Posted by Flat Six

Eric, did you ever get this sorted out?

Cripes - I just saw the dates of the post. This is almost a month old since he last posted.

[EricAlborg]

Apologies for delay, everyone. I finally figured it all out the day before last. And as a matter of good pelican policy, I thought I should close out this thread.

After a few backfires I got an oil leak from cylinder #6. After freaking out, we pulled the valve cover off. No head studs floating around. Phew. Then we used torque wrench to double check. None came loose. Double phew. But I did find 993 (I think?) head stud bolts with the star pattern, which confirmed my suspicion that this engine has definitely been opened.

Because I had pulled out the old tachometer and replaced it with the OEM one, I pulled off the steering wheel and checked my wiring to see if that was causing my issue. Check. Everything looked good.

Then I went to the front of the car. There is a lot of wiring going on there. First, one of the prior owners must of been a cop or something because there is a megaphone wired into the front. There's also an absurd sound system. But all of the ignition wiring looked to be well sorted and there seemed to be no corrosion (something we have to be mindful of out here with our salty sea breezes.)

Then I went to the back too out all of the plugs and started from scratch. Pulled them off and reordered them at the distributor. Double checked which wires were going to which cylinder. Turned key and she fired! When I look at the past posts, there seemed to be two problems. One, the position of the plugs had to be wrong. The pictures convince met that #1 cylinder was +1 clockwise from where it should be. I also had the number on cylinder 2 and 4 switched on the actual wire.

Unfortunately, not a lot of wisdom to offer to the group based on this exercise. Just another "part of the process" one. In any event, thanks to you all for your advice. I am sure to be back to tap into the pelican brain trust soon.

There's some other work to do, but at least

[T77911S]

the bull horn is from a car alarm. i would investigate and make sure it has been (properly)removed.
check the yellow start wire from the ignition sw to the stater. it is usually cut in the front trunk and a relay wired in. remove the relay and splice the wire back together by soldering it and covering it with heat shrink

[ischmitz]

Originally Posted by EricAlborg

Because I had pulled out the old tachometer and replaced it with the OEM one,....

Beware: There are two wires going from the DME to the stock tachometer in a 3.2 DME car. One wire is engine speed (RPM) and the other is used to drive the shift light logic. It carries the engine load (length of the injection pulse). If you mix these wires up when installing the tachometer you will damage your DME permanently.

What's nasty about this is that first the car runs, then within minutes the running gets rough and then it quits altogether while the DME gradually destroys itself in the process. Seems like you dodged a bullet my friend.

Ingo