Another CIS mystery under way
 

heres the deal. starts up idles at 1000 continually rising as the car warms up to 1700 and stays there. new WUR and AAV.
i plugged the hoses going to the AAR (the non-electrical one) with no change.

question: is it possible for the AAV to actually work backward and open as the car warms? just a thought

Please help???:confused: :confused:

anything people

The AAV should be closed when the motor is running. It opens only during starts or whent he motor is off. Vacuum pulls the diaphragm closed when the motor is running.

Do you have a Bentley or Haynes manual?

yeahhh

I say start by checking ignition system to make sure it is working properly and timing is set properly. Then take it to someone with a sniffer and make sure the mixture is proper. It could be that the rich mixture during warmup has too much fuel, and the engine runs better when the mixture leans out. Probably incorrect, but it still doesn't hurt to make sure everything is running properly when fully warmed up.

It also won't hurt to make sure everything is connected up correctly. Thermo time switch, vacuum to the WUR, etc,..

Is your AAR closing?

I have a pre-lambda K-jet so I'm just guessing here, but take it slow and understand the components of CIS. Troubleshooting will be much easier.

i havent pulled the AAV, but it starts out in the regular cold start position, around 1100, then after about 1 minute the idle begins to climb to 1700

Jason, it's bit tough to help without more details. Why did you replace the WUR and the AAR? What were the symptoms before you replaced all those? Did you connect everything back up correctly? Do you have a CIS fuel pressure tester?

its not a matter of "hooked up correctly" everything is right. car behaves like a champ until this sprung up. no pressure tester, i have been thinking abouth one lately though

I have heard that a cracked air box will not reveal itself until the motor heats up. The sympthoms are similar to what you describe. Have you tried the carb cleaner trick to find any leaks?

Get a test from JC Whitney for less than 80 delivered. It's worth it if you have CIS.

Hey Jason.. does the idle fall back down after it warms up?

nope. it stays high

ive checked about everything except timing and advance. i guess thats next. what else could it be??

I have a "deceleration valve" on my model CIS.. you should have one also.. I disconnected it to prevent a somewhat illogical high idle.. don't need it anyway.. they can sometimes be adjusted when they screw up

Two thoughts;
1. As the engine warms up and manifold vacuum increases, the deceleration valve could open and cause a higher idle speed.
2. It could be that your idle speed is actually set at 1700 when the engine is warm and the problem is a low cold idle that will cause stalling. This could be a non-functioning AAR (You seem confused as to AAV and AAR, AAR has the electrical leads).

call it what you may. the non-electrical one has been plugged.
and the electrical one is new. kind of mind boggling

Set the idle at 950-1000 when the car is at operating temp. Then worry about why it won't idle when cold.

sounds like great advice

That's right - you don't adjust idle on a cold motor. That is not how CIS works. You set it at operating temp. 1700 warmed up is way too high. Fix that first, then go into the normal diagnostics.

checked the timing and advance-- all good.
did a pressure test on the advance unit--good

whats going on here??