Home Biz idea for CIS gurus

[notfarnow]

I spent a fair bit of times the last week or so reading up on CIS, trying to get my head wrapped around it. Then I frigged and farted with my '81 SC over the weekend, trying to get a handle on the basics. I have it starting WAY better now, and seems to be running much smoother, although there are still some flat spots.

I always find stuff like this frustrating because the learning curve is SO steep, and there are people out there who know it much better and can pinpoint issues almost instinctively.

Anyway: small home biz idea for the CIS gurus.

Have an engine on a test stand with ALL THE BASICS already sorted out 100%... compression, timing etc. Use the test engine to test & tune complete CIS systems that you sell on an exchange/core basis. Used parts are fine, as long as everything tests to spec. Sell the "sorted" used systems complete with all new vacuum lines etc.

If I knew I could strip off my CIS system and exchange it for a complete used, but tested one, I'd do it in a heartbeat.

[moneymanager]

Yes and you'd hook it up with a vacuum leak and have to start all over again

[racerboyrt]

This is a good idea. The challenge is that all the CIS systems are different. Lambda or not, big runners or small, diff fuel distributors, warm up regulators, BOSCH or permantune, 6 pin or 3 pin on early CIS, the list goes on and on. Some stuff is interchangeable and some is not and as ive experieneced everything effects the system. The good news is that when you get your CIS car dialed in its fantastic, as I've recently experienced working with a really knowledgable CIS mechanic.

[T77911S]

the good thing about CIS is there is no "dialing in" like carbs so to say.
based on the mixture set at idle, the CIS system takes care of the rest of the RPM range and driving conditions.

if it has flat spots or a miss or what ever, the problem is elsewhere. ignition timing, advance, air leaks, compression problems, did i say air leaks? even valve guides and seals. these can make a cylinder(s) run bad, perhaps making you adjust on the rich side to compensate.


you dont need a test engine.
a fuel pump and a jig for the injectors to test fuel volume and spray. other than that, just replace all the seals on the intake runners.
in the end with a fuel pressure gauge, anyone can do this on their car. check and set the fuel pressures, replace all seals, test residaul pressure.

[tirwin]

Personally, the problem is you have a limited local audience. I would love to see some of the experts on here pool their collective knowledge into a video that explains the CIS system and test procedures. I think it would be a huge help and would be a benefit to the community. Let's face it, the CIS system is probably the biggest obstacle to newbies. Almost everything else about these cars leverages transferable skills.

[James Brown]

you don't even need a engine. A test rig would work just as well, meters that would read fuel flow cold and warm pressure, etc. heck, it could all fit in a truck and take this show on the road!!

[boyt911sc]

Originally Posted by notfarnow

I spent a fair bit of times the last week or so reading up on CIS, trying to get my head wrapped around it. Then I frigged and farted with my '81 SC over the weekend, trying to get a handle on the basics. I have it starting WAY better now, and seems to be running much smoother, although there are still some flat spots.

I always find stuff like this frustrating because the learning curve is SO steep, and there are people out there who know it much better and can pinpoint issues almost instinctively.

Anyway: small home biz idea for the CIS gurus.

Have an engine on a test stand with ALL THE BASICS already sorted out 100%... compression, timing etc. Use the test engine to test & tune complete CIS systems that you sell on an exchange/core basis. Used parts are fine, as long as everything tests to spec. Sell the "sorted" used systems complete with all new vacuum lines etc.

If I knew I could strip off my CIS system and exchange it for a complete used, but tested one, I'd do it in a heartbeat.

notfarnow,

I could supply you a complete CIS unit with all the CIS components tested and guaranteed to work but you may not get them to work properly if installed incorrectly. For example, an air/vacuum leak would set you back to square one. There is really nothing difficult about CIS troubleshooting and making your engines run regardless of weather. All the tests needed by DIYers have been discussed and performed by people in this forum. You need a pressure gauge to check your fuel pressures. A pressure test (several methods already demonstrated by members) to detect air leak/s. A gas analyzer to check the exhaust gas CO level, etc.

The only CIS components I know that are slightly difficult to test by DIY'ers unless you have good knowledge of electronics are the CDI and ECU. The rest of the components like WUR, FA, TTS, TTV, AAR, FP, FD, decel vavle, etc. are very simple to bench test.

Tony