Derek911

https://rennlist.com/forums/964-foru...c2-manual.html

Mariu_xas

Installed new battery about 2 weeks ago, when received car... Waiting for third ICV to be sure about it

Derek911

Did you have the problems before the new battery?

Mariu_xas

I'am new owner, bought car from USA auction and car come with dead battery so installed new and trying to figure out what's wrong with her...

dlpalumbo

1) you haven't said if replacing plugs fixed erratic cylinder firing.

2) At rest, if you blip throttle, will you get throttle bounce, i.e., will throttle undershoot bounce up, overshoot and then settle down? This is classic symptom of need for adaptation. Adaptation must be done with car very warm.

I had similar problems for years. Adaptation with scantool didn't help. Bought a PDT999. Adaptation worked, car was rock solid.

Give it a try.

Dan

Mariu_xas

After spark plugs replace no changes... Order new set of wires, caps and rotors... Let's wait.. After those parts replace going for adaptation.

jsoderbe

Just FYI, I have the exact same problem on my 1992 C2. I have tried most of the steps listed, but not using a scan tool. To make things even worse; my problem comes and goes. The car can idle perfectly for two weeks, then it starts to act strange, meaning that it cant catch idle. So I will follow your thread with great intrest!


Regards,

Johan

Mariu_xas

And one more update... New spark plug wires, caps and rotors... One coil was looking corroded so replaced. Engine works more gently.. no big difference.

There is a video about bouncing idle :

ras62

Did you replace the O2 sensor? I had a similar problem which was solved by a new O2 sensor.

Mariu_xas

o2 still old, today's news car starts immediately and stall after 1 min jumping idle.. and starts after maybe six attempts... Can it be symptom of o2?

Tuesday car is going for idle adaptation.. Maybe it helps...

One more question : Can Light weight flywheel reduce cars top speed? For example 5 gear/ 100kmh (60mil) around 3000rpm, at 200kmh (125mph) over 5000rpm.... Is that normal?

ras62

O2 sensor highly likely the culprit. Cold starts ok then hunting when warm.

Flywheel cannot affect speed in gears, the ratio is fixed, maybe the speedometer is not accurate at low or high speed. In 5th gear spped is about 25 mph/1000 rpm or 40kph/1000 rpm

Mariu_xas

Ordered new o2 sensor, hope it helps

Mr.Alex

I had similar and it was the O2. Can try without swapping. Just unplug the O2, disconnect battery for few minutes to reset DME, and then try.

sml

The answer was in the first reply, repeated a few times and you keep ignoring the advice.

The solution is a system adaptation with the Bosch Hammer.

I spent hundreds of hours trying to resolve the same issue as your video and the solution was an easy as following the Porsche instructions .... which is a system adaptation any time you disconnect the battery.

https://rennlist.com/forums/964-foru...daptation.html

After the system adaptation, you can also do this for fun .... I did all of these 'fixes' first before trying the easiest solution!
- new ISV
- Steve Wong chip
- new coils
- new fuel filler neck & cap
- checked for vacuum leaks
- new air filter
- cleaned AFM
- fuel injector cleaner fuel additive
- new oxygen sensor

Mariu_xas

And back again, some time ago after adaptation car runs pretty good. Idle jumping stays but no stall every time. And now turning on ac car works ok, but stall every time when shifting if ac switched off car runs well again.

Any ideas?

p.s 3000rpm/ 100kmh or 60mph is that normal? ( 5 gear )

Top speed about 220-230kmh or 140mph