964 Motor needs an ideal adaptation every battery disconnect?

[Duc Hunter]

My Rat Rod has a 964 motor, and it seems ever time I disconnect the batter (to put the car up for a month or so) this needs to be done. It also seems that a scan tool is required, unlike my 3.2. Is this true?? I need to buy a Durametric et-al and do an adaptation every time?

[Bill Verburg]

Originally Posted by Duc Hunter

My Rat Rod has a 964 motor, and it seems ever time I disconnect the batter (to put the car up for a month or so) this needs to be done. It also seems that a scan tool is required, unlike my 3.2. Is this true?? I need to buy a Durametric et-al and do an adaptation every time?

Just start it normally w/o touching the gas and let it idle for ~5min, then dive it normally, it will adapt as you drive, the first few minutes are just to get the idle right.

You could use a Hammer but it's not necessary

[Duc Hunter]

Bill, Thanks for the sage advise. I will give that a try. Thats what I do on my 3.2.

[jjeffries]

Duc, would this provide a complelling reason to add a battery tender, so you don't lose the set-up? I find one useful just so I don't lose the ridiculously time-consuming adjustments required of my 1990's-era Alpine receiver! Best, John

[911pcars]

Using a battery maintainer is good practice to prolong the life of a stored battery.

Using an auxiliary battery accessory to keep radio presets in memory has some caveats depending on whether the vehicle is pre or post OBD compliant.

On pre-OBD vehicles: few issues.

On OBD vehicles:
- If disconnecting the battery to replace, it’s suggested to use an accessory harness that connects a starter battery to the vehicle through an OBD connector.

Using the above cigarette lighter/9 volt battery accessary can be iffy. It can trigger DTCs and upset the diagnostic system. If electrical work is performed, it can be hazardous. For example, if the vehicle SRS system is being serviced, this could deploy an airbag - NG. The explosion or deployment will at least get your attention. More info on the internet.

If a battery cutoff switch is used, as suggested, install a parallel fused (3amp) circuit between the Neg (-) post and the ground cable connector. With the switch “open”, 12 volts are still available to the vehicle system to maintain radio presets and ECU operation (Engine OFF). It will also allow electrical current parasitic drains to deplete the battery (another project). However, with any significant current demands (e.g. engine cranking, headlights, fan, etc.), the 3A fuse will blow, bringing the electrical system to ground zero. Remember the switch status and/or carry extra fuses.

Sherwood

[GH85Carrera]

The 3.2 Carrera engine management is a powerful 4K computer! It loads that massive program from ROM memory and you are off and driving.

It forgets everything every time it the ignition is turned off. Get in and go. No warm up needed. Just keep RPMs below 4,000 RPM max until the engine is warm.

The 964 is a lot more advanced system and it actually learns and adapts as it is run.

[fred cook]

+1 on the battery maintainer. I use a small 1.5 amp maintainer on both my Porsche and on my XJS Jaguar. The last time I had to change a battery was in the Porsche and the old one (red top) lasted for 7 years!

[Duc Hunter]

I cannot use a battery maintainer as where I store them does have power. Great idea though.