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Posted by: DRPHIL914 Oct 6 2018, 09:08 PM

so its missing every few seconds or so.
like when the heart skips a beat. So how or why would this happen- is it the points module?(hot spark) , seems like the most likely thing. I am going to put the 123ignition distributor in tomorrow, and it will be interesting to see if it still happens.
that will eliminate the fi points plate and the hotspark module in the old distributor.

So has anyone else ever seen this when setting the timing on their car?? if so what did you conclude?

Posted by: Dave_Darling Oct 7 2018, 10:55 AM

Since my car did not misfire or run any differently when the light dropped, I concluded that the problem was with the timing light. Most likely with the pickup clamped around the plug wire. Moving and repositioning the pickup usually fixed the problem--for that occurrence.

--DD

Posted by: euro911 Oct 8 2018, 12:57 AM

Does a tachometer indicate any fluctuation in RPMs?

Posted by: Mblizzard Oct 8 2018, 12:29 PM

Also verify that the pick up clip is oriented in the correct direction indicated.

Most usually have an arrow that points toward plug. Hook up backwards and some strange things happen.

Posted by: porschetub Oct 8 2018, 01:14 PM

My timing light did the same thing and it was a bad contact in the #1 plug wire clamp.
My light won't flash if this clamp isn't fitted in the correct way.

Posted by: PlaysWithCars Oct 8 2018, 09:32 PM

Yes, as everyone has pointed out, its important that the timing light is connected properly. But, I've frequently found that there is an ignition system issue leading to missed spark. Most common for me has been plug wires: carbon core breaking down or the connection between the wire core and the terminals on the end.

Try putting the light on other plug leads. You won't be able to check the timing, but you should be able to confirm consistent plug firing.

Posted by: DRPHIL914 Oct 9 2018, 05:38 AM

thanks for the tips. i can say that i feel a skip or miss when trying to hold it 3500 rpm for timing, so pretty sure there is a missing spark, just not sure if its a bad wire or if its in the distributor. i can say the cap a rotor were replaced the last time i tried to check this out, and its a new blue coil too. Bosh plugs are probably a year old and less than 1500 miles on them.

will post after changing out plug wires, and will go from there

Posted by: TheCabinetmaker Oct 9 2018, 09:17 AM

Before you go wasting money on plug wires, unscrew the wire from the end. Cut 1/2 inch off the end of the wire, and screw the wire back on.

Posted by: Mark Henry Oct 9 2018, 07:27 PM

My light I busted the plug wire clamp housing just enough to cause this issue. '
I had to epoxy it back together to get it to work properly again.

Posted by: jim_hoyland Oct 11 2018, 05:41 AM

and....how did it come out ?

Posted by: DRPHIL914 Oct 12 2018, 07:05 AM

I have not had time to get back to this, I spent 5 hours cleaning yard and pool yesterday, and then pulled the fuel rail and put in 8 new fuel injectors in our '07 Lincoln navigator(196000 miles). we need to take it on a atrip soon and its been running pretty crappy so I needed to get that done first- success, partly but it looks like I have a transmission solenoid that needs to be replaced. intermittent shifting issue and once and a while a code, then back to .... sorry not Porsche content, but it is my tow vehicle so I need it working!!!! I do hope its that simple and not a full transmission rebuild , but at 200k miles almost its probably due. there are a no service transmission so I was thinking about a full flush and clean and refill first. anyone know if you can just replace the shift solenoid packs on these with out having to pull the whole transmission?? they are not expensive from what i see on line.
Anyway the plug wires were fairly new but i will recheck this and see if its the timing light a plug wire or distributor - the 123ignition one is on the shelf but i wanted to sort that out before installing the new distributor.