Won't rev high with A/C on.

[AttaBoy]

What happens if you floor it without the A/C on? Whats the performance like? Does it seem to miss or backfire or flat spot say from 4000 to 5800rpm? If it is doing that under load, then your leads are probably shot, or atleast one of them might be, so might be worth checking them out with a multimeter.

When I floored it the car well well past 5400rpm and it was good, BUT it gets to 5400 quite slowly not as fast as it should be and the compressor disengages and engages again once back to normal driving.

Since the leads are quite old (Approx 2 - 3years) it might be better to get new ones anyway, so I'm gonna just get the new ones and hopefully make get it to run better. See how I go.

 

[boojak87]

Howdy all, I have exactly the same problem. When the aircon's running on a hot day and i'm cruising along she's fine but as soon as i boot it to overtake it will either do 1 of 2 things:

1) Drop down a gear and scream passed like a bat out of hell (When the aircon is disengaged)
2) Rev extremely slowly and stay in the same gear. You can physically hear the engine slurping up the fuel but it just does not get anywhere. During this sort of acceleration you can hear a distinctive hissing noise from the aircon compressor. When accelerating (at any speed) as soon as the aircon disengages there's a sudden burst of torque that feels like the car's just gained an additional 25-30kw.

The car has had the following replaced in the last 12 months:
-Plugs, leads
-Throttle body/IAC and injectors cleaned
-CAI added
-Fuel lines checked for possible leak (getting average economy)
-Extractors, highflo cat and cat back exhaust added (2.5'' all the way through)
-Fuel filter, oil filter and any other filters replaced at last service
-Auto tranny service

(All of these things have been done in order to fix the acceleration/economy issue, but to no avail. I have better fuel economy, dropped from 16.5L/100kms to 13.5L/100kms, all city driving, but it's still not as low as it should be. The car also has the 'commodore shudder' on take off from the lights. I added the Nulon total fuel system cleaner a few times and this seemed to reduce it and made the car accelerate better/better economy also.)

Clarification on this would be awesome! I always thought i'd had fuel delivery issues. The car's due for a service very soon, should i ask them to check it out as well as the fuel pump and fuel pressure regulator? Also i think my oil pump is leaking, could this play any havvoc?

Cheers,
Boojakz.

 

[hako]

Try switching the A/C switch off when next you floor it and hear the hissing sound - this will instantly disengage the compressor and verify if its the problem. Do it when it is actually hissing. Compressors usually only can be heard when the bearings are shot or the system has too much gas.....normally they are no noisier than an alternator.
Come to think of it, that hissing could also be coming from a restricted cat or exhaust, intake or exhaust manifold gaskets damaged/missing etc. You'd also imagine that the auto should kick down irrespective of whether the A/C is on or not - so maybe there is a problem with a sensor not telling the auto to shift back a gear or two.
Good Luck.

 

[boojak87]

Try switching the A/C switch off when next you floor it and hear the hissing sound - this will instantly disengage the compressor and verify if its the problem. Do it when it is actually hissing. Compressors usually only can be heard when the bearings are shot or the system has too much gas.....normally they are no noisier than an alternator.
Come to think of it, that hissing could also be coming from a restricted cat or exhaust, intake or exhaust manifold gaskets damaged/missing etc. You'd also imagine that the auto should kick down irrespective of whether the A/C is on or not - so maybe there is a problem with a sensor not telling the auto to shift back a gear or two.
Good Luck.

Hissing is definately there ONLY when aircon is on. Exhaust system is all brand new (as stated in prior quote) and all bolts were tightened up after one month to ensure there was a pressure tight seal at all joins. I've always had the problem with it not wanting to kick down the comp never pulls up an error though?!?!?

Cheers,
Boojakz.

 

[kopper69]

Hissing means your low on gas. Guaranteed. Get her filled up and it wont do it any more. If you have had a regas in the last year you may have a leak in the system.

 

[Boonz]

most places wont re-gas your system until they know it is leak free otherwise a company called arctick gets up their ass about why there is less reclaimed gas to new used gas...

usually leaks are around the compressor seals. condenser join seals and TX valve joints...

 

[AttaBoy]

Update: It the compressor bearings, Not sure if that can be fixed??? Is it simple as swapping for a new one??

 

[HoldenManDan]

Update: It the compressor bearings, Not sure if that can be fixed??? Is it simple as swapping for a new one??

Hey man

The comp bearings on mine are stuffed too, the drive wheel actually has space to rattle around, and does especially when idling. They can be repaired, price depending on how much stuffing around is involved. I got quoted $150 to fix if they don't need to regas, but $250 if they do. Hope this helps... let us know how you go! :thumbsup:

 

[hako]

There are 2 different types of bearings - the one that HoldenManDan is (maybe) talking about is the one in the electrical clutch which engages/disengages the compressor. When the aircon is ON the clutch locks solid. When the aircon is OFF the clutch frewheels and if the bearing in the clutch is buggered it will make a noise and rattle. They can easily be replaced.
AttaBoy appears to have buggered bearings in the compressor which require disassembly of the compressor which really means its cheaper to buy a new one. That is unless his compressor rattles when OFF.
Thats the way I see it but I'm just putting my 2cents in.

 

[HoldenManDan]

mmm yeah i'm pretty sure mine rattles all the time (ie when a/c is on AND off, a/c still works fine when on too), so that means....?

cheers