Permatune Questions

[techguy]

Installed a Permatune unit in my 72T with 75 911S Carerra motor and Webbers...wow good acceleration then when you hit 2200 RPM its like a mini turbo.....strong and smooth all the way up.


Questions:

1) Is it normal for good initial acceleration then at 2200 RPM a good strong kick continuing all the way up? Not a complaint it cool!!

2) My Tach bounced around a bit with the original Bosch CD, it seems to bounce even more now however, settles down almost to normal when the car get warm. Maybe a bad wire?

3) What does the white wire connected to the distributor do?

?

Background

Car was on a PCA fun run last weekend and 50mi into the event it died...no spark at wires, no power to coil. Checked points and all connections. Initially we thought it was the Bosch CD unit so I obtained a used (Blue 1977) Permatune and Coil from another PCA member. Installed the new unit and still no spark. After 7 hours of playing around interchanging coils, checking voltages, diagnostics on the Bosch and Permatune units and cleaning, gaping and cleaning the points again nothing!! We cleaned the points and gaped them one last time and it fired. The points look perfect but just would no go all afternoon. I installed a new set of points once the problem was isolated and left the Permatune in. Drove the car back home last night (100 mi) and its running well. I need to gap the plugs for the new Permatune today to finish the project.

Thoughts guys???

[techguy]

Ok, I decided to gap the plugs to .064 as per Permatune's specs. I also cleaned all the grounds and wires from the distributor to the Permatune unit (white wire). It appears that acceleration is a bit smoother. I notice a bit of backfire in the webbers now and then. I still have to check the timing and check the carbs for balance. Any other thoughts?

[azasadny]

TechGuy,

I installed my new PermaTune CD unit last summer and set the gap to .60 and had all kinds of starting problems. On my mechanic's recommendation, I regapped the plugs to .30 and replaced the Bosch/Beru plug wires with Jacobs Electronics wires and I haven't had a single starting problem since. Check your plug wires and regap the plugs!!!

[azasadny]

Techguy,

I have Bosch K-Jetronic CIS on my car and yours is carbed, but I would regap the plugs and replace the wires. I paid $129.95 for the wire set and they stopped all the backfiring and cranking I had to do to start the car... Just my .02 worth...

[techguy]

Gap and Coil
Any other suggestions for plug gap? I think I may go .030 I am running Bosch wires and they look almost new. I also have 2 Bosch coils 0.221.121.001 and 0.221.121.006 one better than the other with the Permatune?

[RoninLB]

Originally posted by azasadny

I regapped the plugs to .30

and replaced the Bosch/Beru plug wires

ditto,

and Bosh's Beru plug connectors are a problem waiting to happen, IMO.. even if brand new, IMO

[techguy]

Well,

I decided to gap the plugs @ 0.030 and took the car out for a spin. I actually think things were a bit worse, almost like a wire was broken or one had come off a plug above 3000 RPM. The funny thing is that all is smooth up to 3000 RPM. I assume above 3000 the coil is really working hard.

On a whim I decided to install the other Bosch coil (0.221.121.001) and went for a ride. It sputtered and back fired for about 100 yards and cleaned right up. Now the car runs smooth and really strong from 0 RPM on up. I cannot believe a coil can make such a difference......looks like the tech articles at Permatune are right!!

http://www.perma-tune.com/Technical%20Support/Ignition%20Modules/porsche/911.htm

[Randy Webb]

"The points look[ed] perfect but just would [not] go all afternoon."

- Points might have had some buildup on them -- grease film? dirt? -- and you knocked it off by messing with them.

Or maybe you have some bad wires.