Alfa Pages

nzoliver · Posted: Mon May 09, 2005 10:14 pm Post subject: High idle speed

Hi all,

My '91 1.7 33 8v is idling at 1200-1500rpm when warm. Any ideas? Got a suspicion the battery may be on its way out as this affects a lot of cars such as anything with Bosch Jetronic like Audis and Benzs.
_________________
I've a few of these now but still I come back for more!! This time it's a '91 1.7IE.

tvatavuk · Posted: Tue May 10, 2005 9:58 am Post subject:

It can also be thermostat that can't close fully, or temp sensor...
_________________
Tino Vatavuk
Little black dress which replaced Alfa Romeo 33 S 16v Permanent 4 GMo

bobbber · Posted: Tue May 10, 2005 10:12 am Post subject:

What about the cold start throttle bypass system marked as 2 on the diagram :

The idea of this system is to allow extra air into the intake manifold when the engine is cold. If the valve stays open when the car is warm, this will lead to higher idle.

Warm the engine up, and then squeeze the pipe to see if this effects idle - if it does the electrical connection to the valve may be faulty or it could be the valve itself.

Rob
_________________
Fiat Bravo 165 Sport

bobbber · Posted: Tue May 10, 2005 10:12 am Post subject:

Sorry! Bad link!
_________________
Fiat Bravo 165 Sport

ak863 · Guest

there is a way of decreasing the idle speed..

bobbber · Posted: Wed May 11, 2005 10:53 am Post subject:

Certainly is....

At the front of the intake manifold there are two rubber pipes. The fat one is from the 'Cold Start Throttle bypass' (see previous post).

The thin one is to adjust the idle speed - you will need two spanners - warm the engine then adjust.

Rob
_________________
Fiat Bravo 165 Sport

nzoliver · Posted: Wed May 11, 2005 9:02 pm Post subject:

Thanks all. Will look at it today maybe. I wish I had pictures like that to service it meself. Anyone help?
_________________
I've a few of these now but still I come back for more!! This time it's a '91 1.7IE.