CIS trouble - low idle during warm up

[deftom]

Hi guys,

I have a friend who have some problems with his car.

On cold start, the car is doing some yoyo during the first 2 minutes. After that, the iddle gows down to 500 RPM and slowly reaching 950 RPM.
When the car is hot, it works preaty well.

Here is the car configuration :
- it's a 3.2 with a 3.0 SC european engine
- the fuel distributor came from a 188 HP engine
- the Wur came from a 204 HP engine
- the auxiliary air valve closes within 8 min
- the engine was recently rebuild with 964 cams and Malhe 97 mm pistons
- all the CIS parts were rebuild and setup correctly and or tested separately
- the mixture was setup to 2.7
- all the ignition parts are also new

We sticks with this problem for a while and couldn't figured out was causes the issue.

I hope I made myself clear enought .

Thanks a lots for your help.

cheers

[boyt911sc]

Originally Posted by deftom

Hi guys,

I have a friend who have some problems with his car.

On cold start, the car is doing some yoyo during the first 2 minutes. After that, the iddle gows down to 500 RPM and slowly reaching 950 RPM.
When the car is hot, it works preaty well.

Here is the car configuration :
- it's a 3.2 with a 3.0 SC european engine
- the fuel distributor came from a 188 HP engine
- the Wur came from a 204 HP engine
- the auxiliary air valve closes within 8 min
- the engine was recently rebuild with 964 cams and Malhe 97 mm pistons
- all the CIS parts were rebuild and setup correctly and or tested separately
- the mixture was setup to 2.7
- all the ignition parts are also new

We sticks with this problem for a while and couldn't figured out was causes the issue.

I hope I made myself clear enought .

Thanks a lots for your help.

cheers

I like to help you but your information is too vague. Please provide the following:

FD ID Bosch number
WUR ID number
AAR ID number
What do you mean mixture set @ 2.7?
What are your fuel pressures readings (cold, warm, and system)?
How is the integrity of the vacuum system? Did you test it?

Keep us posted. Thanks.

Tony

[deftom]

Hi Tony,

Thanks for your help.

here is the information you asked :

FD ID Bosch number : 0438 100 031
WUR ID number : 0438 140 089
AAR ID number : 0280 140 201
What do you mean mixture set @ 2.7? 2,7% measured with a gunson gastester
What are your fuel pressures readings (cold, warm, and system)? Cold = 1b @7° celsius, Warm = 3,1b without vaccum (3,8b with vaccum), System = 4,5b
How is the integrity of the vacuum system? Did you test it? Yes, everything seems to be fine

Thanks .

[deftom]

Hi guys,

After few research, I foudn something that my be our problem :

1981 SC CIS - low idle - wrong WUR?

I'll keep you in touch if it's that.

Cheers

[fred cook]

You also need to check the AAR and make certain that it is opening and closing properly.

[deftom]

Actually, He already tested it. When it's cold, the TAA is open and i took 8 min to close.

[pmax]

Originally Posted by deftom

Actually, He already tested it. When it's cold, the TAA is open and i took 8 min to close.

Have the timeline for the FP as well ?