83 911 sc no spark - Page 2

engrguy · 09:00 AM

I checked the "green wire" according to the Perma tune sheet (on there web page and copied above to here by Bob). All good.

I spoke to Lonnie at perma tune about the different reading I got on the Perma trune he said that was probably not it but I could send it to him to have checked out.

Bob Kontak · Bob Kontak's Garage

Update?

engrguy · 08-29-2012, 09:01 AM

Going to check the coil next. Have to get one 1st.

engrguy · 09-08-2012, 07:47 AM

OK here is the latest. A nice guy loaned me a silver perma tune. I put it on by just unplugging the old one and plugging in the owner. Didn't unbolt the original one. Hit the key and it started right up. So one would think great you know what it is it is your perm tune. I let it run for 10 minutes or so. Plugging back in the original one hit the key and it started right back up.

Any thoughts??

Bob Kontak · Bob Kontak's Garage

Immediately, those as brilliant as we on this forum would think bad connection at the box.

But you had it off two or three times to check things like power, resistance, and ground. So this was not the fist time the plug was off.

I can't answer it unless you somehow wiggled wires in the socket that last round to finally make a connection.

engrguy · 09-08-2012, 08:20 AM

I'm pretty sure I didn't wiggle any wires but you never know. I thought the same thing at first. But I had plugged and unplugged the original one several times during the checking of this before the loaner arrived.

Bob Kontak · Bob Kontak's Garage

Get the Bosch box restored and keep the P-Tune for back up.

Double check the grounds where the aluminum CDI mounting plate bolts to the chassis. I think it is a relatively nasty place to get to like well behind the fuel filter. I honestly do not know if that is where the CDI goes to ground so I may just be blowing useless smoke.

However, I do know these units like all other 'lectric stuff needs a good ground which is a no duh statement. Hoping for the best for you.

engrguy · 09-09-2012, 04:00 PM

Newest update. Went out this am to start the car..... cranked no start. Put the loaner CDI perma tune in and started right up. Idled for a bit, plugged in the old one and nothing no start. Must be intermittent perma tune cdi.

Bob Kontak · Bob Kontak's Garage

Get the Bosch rebuilt and borrow your pals CDI for two weeks.

engrguy · 09-11-2012, 04:48 PM

Bosch is off for rebuild. Perma tune off to Lonnie 9nice to have an extra one on the self in the garage) using the loaner.

emac · emac's Garage

It's your cd box. I chased the same issue for a week got a box and she fired right up. Have read many posts stating they either work or don't I know for a fact they could work for a day or two as mine did. Pain in the ars to get the mounting screws in helps if you have a double jointed neck. Not as hard as getting the clamp back on the fuel filter.

boyt911sc · boyt911sc's Garage

Quote:

Originally Posted by engrguy

Newest update. Went out this am to start the car..... cranked no start. Put the loaner CDI perma tune in and started right up. Idled for a bit, plugged in the old one and nothing no start. Must be intermittent perma tune cdi.

You have demonstrated twice that the old permatune CDI is 'kaput'. Get a replacement CDI that is working and reliable. I have a '78 SC for more than 20 years now with the original OEM Bosch CDI. And started saving spare parts for this car. The first spare CDI unit was purchased in the late 90's and afterwards acquired a few more. Luckily, I never had the opportunity to use any of my spare unit (knock on wood) and they are collecting dust.

The car is 34 years old with original distributor and CDI. And at the rate I'm going, I won't be able to utilize most of these spare parts.

Tony