Ac Idle Up Going High After Some Time

[tilvin]

Hi Friends,

My car is 1999 Peugeot 306 - carb model wagon. When I start the car in the morning the rpm is very low around 500. Then when I put A/C RPM will up to 900. Then it will run fine for another 15 minutes. But after that when the A/C is on the RPM will be is fluctuating between 1100 to 2000 in the idle. So it becoming really difficult to shift the gears when it reaches 2000. But when I off the A/C it is back to 900-1000 range. What can be the issue.....Pls assist.

Tks.....

[Rumesh88]

Did anyone carry out a adjustment in idle speed or meddle with vacuum lines recently?

[tilvin]

I do not know. Actually I have bought this car recently(2 weeks back) and at that time A/C was not working. Repaired the A/C. When I switch on the A/C, this issue is coming.....

[Rumesh88]

If that is so the problem can be one or more of many things (idle air control, vacuum leak, wrong vacuum connection, faulty vacuum valve) for you are not aware when the car last ran without a problem but with AC on. Some of our mechanics have a habit of messing up with the vacuum lines particularly when they are left unused. I'm afraid my two cents wouldn't work.

[charitha19]

try a retune with a good carb guy.. there is an AC idle up value that pushes the RPM up.. now in EFI models its done through the ECU, atleast for the new models. the older models use a solonoid kind of a contraption to mechanically raise the idle so that the car can compensate for the AC load.

[tilvin]

Thanks Guys for the assistance. I will try as you suggested

[miniace]

First suspect is ICV (Idle Control Valve). Check for operations, connectors and wirings. Check for leaks in vacuum system. This is a common fault with Pugs.

MINIACE