Vitara idle surges when Air Conditioning is on...

[Impulsive]

Hi Folks,

I was hoping you guys might be able to help me with an irritating problem I have with my Vitara. It's a 1989 JLX with P/S & Air...

The problem is that when I turn the air conditioning on, the engine revs unconrollably whenever I would otherwise have it at idle, ie; at sets of lights, etc.

It's not a constant rev, rather, it revs to about 2000rpm, then drops to idle, then revs again, then drops, etc. This happens about every two seconds and usually goes on for anywhere up to about 10-15 seconds, then stops.

If I'm sitting there with the air off, and switch it on, this will also happen.

It's apparent that it has something to do with the "drag" placed on the engine by the compressor, or an electrical fault.

I can feel the accelerator drop beneath my foot while it's happening, so, does the carby have a solenoid on it that might be pulling the accelerator cable? if so, it could be an electrical fault (maybe?).

I really want to fix this problem because I want to avoid having to switch the air conditioning off at lights, etc.

Thanks in anticipation of any suggestions you may have.

Regards,

Adam

[SiKiD_01]

Have you had a look in the Vitara Bible?

[Impulsive]

Yeah, I did actually... and well done, by the way, Skid. Nice work.

Problem is that the appropriate story in there is largely irrelevent to me 'cause it's carby, not EFI (and doesn't have the valve or sensors spoken about).

I WILL check the thermostat housing though, and see if that helps.

Regards,

Adam

[kimclive]

Hi Adam,

Mine is EFI so the issues are electronic as you said.

Have you tried looking at the carby to see what is going on while it is surging. You may be able to see the movement and track it back.

Cheers

Clive

Sorry, I had a shocker trying to post this as you saw!

[SiKiD_01]

sorry i cant be of much help, but there are a lot of vacuum lines on the factory carby, and i found on my old carby that some of the vacuum hoses were either split, had come off, or hardened over time.

if all is well, and no leaks, then maybe the actual carby itself is in need of attention. i dont have air of p/s on mine.

good luck.

[Impulsive]

Hi guys,

Thanks for your suggestions. I suspect that there is a lot of issues in relation to the air lines that I need to investigate, and the suggestion of looking at the carby and tracing back is a valid one.

Again, many thanks.

Regards,

Adam