Chucks928

Land......the thermo time switch was replaced ( I may have listed it as the temp time switch). Along with temp gauge sensor. The cold start injector was sent out with the injectors to Witchhunter to verify it was in good shape. If memory serves me ,I think from there I replaced the ignition switch,as it was showing signs of wear and it was mentioned as a possible item that could cause issues. I,m not sure what else is involved in the cold start cycle other than the actual wiring harness?
also..... I checked all injector connectors with a noid light and was getting a signal to all. Also checked plug wires with timing light and all wires are firing.... but....I have noticed that on most cylinders I can pull the injector plug and the car will definitely misfire..but on 1 or 2 it doesnt seem to affect the engine. its idling with a slight misfire and doesnt change when an injector is unplugged. I,m wondering if it may be a wiring harness issue or? Chuck

soontobered84

If you had 2 plug wires crossed, neither would be firing at the right time and therefore if you pulled those 2 wires it wouldn't make any difference as to how the engine ran whereas pulling any other wire WOULD make a difference.

Triple check your spark plug wires to make sure they are connected to the correct cylinders in relation to the distributor.

Chucks928

Soon, The wires have been on and off a few times so it cant hurt to double check proper order. Any ideas will help as I have somewhat hit the wall on troubleshooting. The WSM has been a big help,but not being familiar with the Porsche makes it a sloooow process for sure.

Otto Mechanic

Looking at your list I think it's hard to guess there's a failed component you haven't replaced already, much more likely something you've done went back in in the wrong order. I think plug wires are a good thing to check first since it's very easy to get those confused, next would be vacuum lines for the same reason.

Best of luck, wish there was a silver bullet.

Regards,

Mrmerlin

Please put a piece of tape around the #1 plug wire where it attaches to the distributor cap ,
and take a picture of the engine and post it.
Look /google for the picture of the firing order,
and verify that you have the correct wires installed.

Otto Mechanic

I had a very similar failure myself a few months ago that was eventually blamed on a bad distributor cap and it was equally mysterious. After checking the plug wires you may want to look for carbon traces on your distributors?

Chucks928

tape marks #1 plug wire
Thanks for the input ! The holiday has kept me busy a. As per MrMerlins request here is a pic of dist cap and wires. Tape is on the #1 wire and going clockwise,the wires are..1-3-7-2-6-5-4-8.
I,ve installed a new Bosche cap and rotor and new plugs. The wires were installed back in 2012 according to POs receipts. they are economy wires.

Chucks928

Bump

AirtekHVAC

Posting in your old thread! I do not know how I missed it, but I could have helped you, as I have had a very similar issue, or should I say issues, with my 82. Don’t give up yet!

read my great white thread if you have a chance, you may find a couple of nuggets....don’t know if you changed the ignition coil, but I had some probs with that thing as well...documented in my thread!

good luck!

Chucks928

Thanks Air.... this past summer the 928 was put on hold as I was finishing getting another car back on the road. The Plymouth is back up and running after 15yrs sitting in the garage and now its time to put some hours in on the 928 before winter hits. It has kept me chasing my tail at times but I,m determined to make it roadworthy by this time next year.
Chuck