Hard Starting First Time only

[satu]

Hi,

I have a 1995 Porsche 968 with 115K on it.

After the car has been sitting for a while, the first time I try to start it, but occasionally it doesn't start. Something like loosing power. If I then turn it off, I can immediately start it without any problems.

Recently done Tune-up(Cable, Spark plugs, Ignition Coin, Rotor, Oil, Fuel Filter, Fuel Pump, Oxygen Sensor and Water Sensor)

This is the video: ‪1995 Porsche 968.MP4‬‏ - YouTube

Please, help me. Thanks.

[Mukilteo911]

I have the same issue with a 968. Mine also takes two tries to start when cold, like it cant get fuel, and inbetween 2k and 3k studders like crazy. I read in one post the studdering under load was faulty O2 sensor. Im thinking they are related.

Anyone else have ideas on this?

[John_AZ]

Hard starts can be caused by fuel problems.

Check the FPR --Pull the vacuum line and check for dampness/fuel. Even if no fuel is noticed, it could be bad.

If you have 115K miles, it may be time to send the injectors to WitchHunter Performance - Injector Cleaning & Flow Testing Services or similar or buy new. You may have a slight leak and this will depressurize the fuel lines.
At least pull and reseal. There are a few DIY cleaning suggestions on the net.

You could pull the injectors, get plastic baggies and put a piece of brown paper bag in each baggie. Wrap a baggie around each injector---in the morning, the paper will have a mark if the injector leaks. Have new seals lined up.

Maybe try a couple of cans of Chevron PREMIUM fuel injector cleaner and premium gas for a couple of tanks.

There are voltage checks for the O2 sensor---I am not sure why the studdering is related to the O2 sensor. The DME engine temp sensor is more the problem.

Just ideas

John