Anyone here with CIS FI in a 914, six cylinder engine of course.. Options

[DougC]

I have a couple of CIS specific questions and was wondering if anyone on the list might be able to help?

Doug C

[lapuwali]

QUOTE (Cap'n Krusty @ Oct 10 2005, 12:19 PM)

QUOTE (lapuwali @ Oct 10 2005, 12:04 PM) The 2.7 CIS is "basic" CIS.  It requires almost no electrical power to start and run.  Later versions (used on the later SC) had an O2 sensor, some electronics, and a control valve, they all required switched power.  The 2.7 version, however, doesn't have this.  With no power, you'll find cold starts to be harder, but not impossible.  The cold start valve won't open, and the WUR will take much longer to stop adding "cold" enrichment.  However, unless the temp outside is below 50dF, you shouldn't have any trouble starting the engine dead cold with no cold-start system. Only the fuel pump and the ignition need power.  The fuel pump can be checked by just feeling it with the power on.  It should vibrate.  You can also use a pressure gauge (rated for at least 10 bar or 150psi) on the fuel line between the pump and the fuel distributor.  It should show 6-7 bar or around 80-100psi with the fuel pump on.  If it doesn't, your fuel pump is bad, or perhaps your filter is terminally clogged.  If you suspect the filter, place the pressure gauge just after the pump (before the filter). If you have fuel pressure, take the airbox off, and take off the snorkel between the air meter and the throttle body.  The air plate should be clean, and should move VERY easily (it goes up, so reach into the airbox and push it up with a finger).  If there's any resistance, it's possible your fuel distributor is gummed up.  Don't try to clean it yourself. When starting CIS, you need to keep your foot OFF the gas while cranking.  You may need to blip the throttle a tad AFTER it catches, but don't give it gas while it's cranking, or you'll discover why the airbox pop-off valves are so popular. A lot of what you're saying here is wrong. The 2.7 CIS requires power, as do all basic CIS systems, to the control pressure regulator (WUR), the auxilliary air valve, and the cold start valve system. IIRC, on some 2.7s there's also a circuit for cold start enrichment so the throttle is opened slightly without the need for a throttle position lever. Without power to these systems, cold and warm mixtures aren't set, idle speed is too low cold or too high warm, and the engine will be a real bit*h to start on cold days. The Cap'n

But it will start (as long as it's not too cold). I'm trying to convince Doug that his no-start condition is NOT electrical, because I don't think it is. Having all of the warm-up stuff disconnected won't prevent it from starting and running, it just makes it harder to start when it's cold out. The basic CIS system itself doesn't require any power at all, and if it's 80dF out, you won't even notice the warm-up stuff doesn't work.

The warm mixture will be set fine once the WUR is warmed up by the engine itself, it just takes longer. The AAR should also close once the engine bay gets hot enough, and will only cause a high warm idle if it doesn't. It won't affect mixture at all. The cold-start valve only works during cranking, and the extra fuel isn't required until it gets very chilly (below about 50dF, from my own experience).

Basic diagnostics: ignore the ignorable when trying to track down a problem. Only pay attention to the ignorable when you exhaust all that's not ignorable. For a no-start, warm-up stuff is ignorable unless it's COLD out. Once Doug has the engine starting and running, THEN he needs to make sure the warm-up stuff is operational. Chasing warm-up system electrical problems when the engine won't even start, however, is only ignoring the real problem.