[tirwin]

CIS gets a bad wrap. Some of it is deserved and some of it is undeserved. Some people have experience with carbs. Even if you don’t have experience with carbs there are plenty of people who do understand carbs. Same goes for EFI. CIS doesn’t have the same universality, so if you want it fixed right you have to commit yourself to understanding how it works. Some people aren’t willing to do that.

A common issue I see with people troubleshooting CIS is the expectation that there is a singular smoking gun when it comes to finding and fixing problems. They expect that if they can find one easy thing all their problems will go away. The reality is that CIS cars often have more than one problem. People who end up owning CIS cars often inherit cars where some maintenance has been ignored. Rather than finding and fixing the underlying problem, some previous owner or mechanic treats the symptoms instead. For example, continuing to tweak up the idle AFR when there is a slowly worsening vac leak. We’ve had shops post here asking questions about a customer car. And what they’ve done first is usually swap some expernsive parts with no methodical troubleshooting.

CIS cars run great when they are working as designed. But if a prospective buyer is an instant gratification kind of person, CIS is not for them. But the opportunity is there for people who have patience.

A downside of CIS/SCs compared to the late Carreras is that if you want cheap HP gains, CIS isn’t really an option. You can change the exhaust and put a Steve Wong chip in a Motronic for pretty cheap. There really isn’t such an option for a CIS car.