BorrowedFunCarrera3.0

Hey guys, pretty new to the site and working on helping my father-in-law restore this rarity. We have a 1976 Carrera 3.0 in good condition, just severly lacking in love and maintainance. It really has sat much of the last 7 years and just taken it under my wing recently. Had it in the local Porsche service shop and had some shifter work and other misc things. They said they had fixed a "rough idle" condition by fixing a vacuum leak in the fuel injection. Ever since I picked it up, however, I noticed it seems to be running lean. It certainly gets hot quickly and stays very hot, mostly at or above 120 on the guage. Additionally, it lacks the power it once had and the idle hangs for a bit on decel. I am wondering if this is a repair/adjustment that I want to tackle or something best left for the pros. I certainly have the mechanical ability, but figure if there is a good deal of time and money involved in speciality tools it may be best to pay the shop. I'm not sure of the quality of this shop, as they seemed to vacilate between answers to fairly simple problems. Referrals to shops in Orange County CA would also be helpful. Any input or resources would be great. Thanks!!

Hobbsie

My 83 has a fuse that runs trunk & interior lights that also powers the frequency valve in fuel system. When I bought the car, I had similar issue and found the fuse blown due to trunk light power wire shorted. Once the fuse was replaced, it ran much better.

Brett San Diego

O2 sensor and frequency valve didn't come into use until 1980.

With the engine sitting for so long and an unkown previous history, it's time for a good baseline on the CIS system. Huntig down and correcting any vacuum leaks is a good start. If you're not familiar with the K-jetronic CIS, and you want do DIY correctly, there are some good books to read. Proper fuel pressures (system pressure, cold control pressure, and warm control pressure) are crucial as well as proper setting of the fuel mixture and idle. The fuel pressures are easy to measure with the proper gauge. Setting the mixture properly requires an exhaust gas analyzer. I'd recommend a professional mechanic who has experience with K-jetronic for this. Idle is easy to tweak by turning a screw and will be done along with the mixture by the professional. Some with plenty of experience tune their CIS mixture by sound and feel. I feel better going to a pro.

Personally, I'd start with performing a valve adjustment, doing an inspection of the air sensor plate and its movement, check for major vacuum leaks, check fuel pressures (correct if there is a problem), then head to the mechanic for timing, mixture, and idle check and adjustment.

Brett

Brett

BorrowedFunCarrera3.0

Thanks so much for the replys, I have definitely checked the fuses as another person recommended similar. Although I dont have much of the electronics of the newer rides. Brett, I will start with your recommendations and go from there. Hopefully someone will chime in with some referrals to a good shop in Orange County so I can try them.