Engine cuts out when a/c on

[KMC-DMC]

Hi All,

My car now idles properly thanks to the help at Eurotec and the car finds its idle speed after revving.... although the revs increase slightly as temperature increases

The issue is when the A/C is turned on, the oil pressure drops to approx 20bar, volts drop to 8v but more importantly the engine cannot find idle after revving. Actually there's no hunting for idle It cuts out.

Any ideas on this?

Note that I had no issues when i was driving home after eurotec..

Kevin

[Tourettes Tony]

could be the idle motor or idle speed controler, the oil pressure is dropping due to lower idle so i wouldnt worry about that as long as i doesnt stay the same when you rev it hope this helps TT

[mnickels]

Kevin

I remember Nick testing your idle speed controller and it was sticking on one side sometimes. I reckon this is your problem here as well.

Matt

[KMC-DMC]

Thanks Tony , Matt.
When i get back form holiday ( Ireland and Spain ...can't wait) I'll take off the idle controller. its a sealed unit so I guess a new one is required. I too remember it sticking a bit when Nick tested it.
Strange that it happens only when a/c is on..... otherwise its grand,
Kevin

[mnickels]

When your AC is turned on the clutch engages placing an additional load on the engine. The idle speed motor should correct the rpm to compensate but if it is not working then that is why your engine is cutting out.

That is how I see it anyway lol

[Tourettes Tony]

your spot on there, my idle motor has more horse power than my engine lol TT

[Rich Hanlon]

I have a similar problem in that the revs very are erratic when the car is hot - does anyone reckon that could be the idle-speed controller too? - And if so - how can that be tested?

Cheers folks,

Rich

[NickT]

I remember testing it and it was ok and adjusted the throttle to compensate.

I can loan out an idle speed control ecu for testing.

NickT

[KMC-DMC]

I removed the motor last night and blew some carb cleaner thru it. And a bit of metal cam out. Now the motor isn't working so I've ordered a new one.

Nick, when I get home from holiday I'll contact you about the ECU. Although these are sealed units you said they can be repaired?
Kevin

[KMC-DMC]

I replaced the Idle Speed Motor but car is still not idling with A/c on......must be the ecu....

[NickT]

Sent you PM re lending you my spare known working ecu.

RichH should be able to fix your old one in next to no time.

Nick.

[KMC-DMC]

Hi Nick,
I installed your spare ECU and bingo! - it solved the idle problem.

When i took my old one out I found someone had already opened it at some stage.. see the photo.