Jump to content
SAU Community

R34 GTT AC short cycling ? Normal behaviour?

George.
 Share

Recommended Posts

George. Newbie

George.

Posted
Posted

Hey guys,

Just want some advice on r34 GTT ac system. Since I’ve owned it, the ac compressor, doesn’t matter the set temperature or ambient temperature, runs for around 10 seconds then disengages the clutch, then re-engages everywhere 30 seconds or so and keeps repeating this. 
 

is this normal?

 

I had it recharged today as it was slightly low and thought it would fix it but still does it.

it cools fine in summer even prior to the recharge, except for the usual warmup when stopped or in traffic (still yet to wire overheat fan to on with ac)

 

any thoughts would be much appreciated 

GTSBoy Grand Master

GTSBoy

Posted
Posted

Is the pressure switch healthy?

Have you put the control unit into diagnostic mode to see what it has to say about faults?

FWIW, it should not short cycle like that. In fact, the fact that is is "climate control" means that the compressor should usually stay on all the time, and the controller blends the super cold air from the evap with heated air from the heater core to achieve the setpoint you're asking for. The only time when it doesn't do that is when it is set to "ECON" mode. I think.

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

If it's cold in summer, then no issue.

If it's cutting out every few seconds and you're not reaching your target temp, then there's an issue.

One could be the pressure switch and the other issue could be the temp probe inside the evaporator.

  • 4 weeks later...
George. Newbie

George.

Posted
  • Author
Posted

Hi guys,

thanks for the replies. 
I will have to wait till summer to test properly, but it short cycles both when heating and cooling.

I’ve ordered a new internal temp sensor that sits under the vent in the steering wheel

also, GTSBOY, I have an Apexi FC ecu, I’m assuming I won’t be able to diagnose or would it still work? Could the ecu be causing the problem??

 

the pressure switch is quite cheap I will get a new one and try it out, hopefully it doesn’t require purging the refrigerant again?

GTSBoy Grand Master

GTSBoy

Posted
Posted
34 minutes ago, George. said:

also, GTSBOY, I have an Apexi FC ecu, I’m assuming I won’t be able to diagnose or would it still work? Could the ecu be causing the problem??

Putting the climate control CU into diagnostic mode is independent of the ECU. You just have to do the dance prescribed in the manual. No, I do not know what the dance is. I have an R32, so use the dance in the R32 manual.

On older cars, I would have said "no, the ECU should not affect whether the A/C works".... but for an R34 that might be wrong. I don't recall the detail, but there was extra mods required to make my R32 A/C work against the R34 ECU. The R34 ECU apparently gets involved in the running of the A/C more than earlier cars did. Theoretically, if the PFC is a true plug in, then it should just work the way that the original ECU does - wrt A/C. But there's always scope for them to have not cared.

37 minutes ago, George. said:

the pressure switch is quite cheap I will get a new one and try it out, hopefully it doesn’t require purging the refrigerant again?

Nope. Pressure switch out = getting the fridgey out to pump the gas out before pulling the switch. The switch really cannot sense gas pressure unless it is up against the gas.

Dose Pipe Sutututu Grand Master

Dose Pipe Sutututu

Posted
Posted

There's another sensor that sits inside the evaporator, that's a C U N T to get to, but can be done without removing the entire unit.

Usually it's not the sensor that dies but the actual capacitor in the circuit (part of the plug that dies).

 

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • The Bogan
      NC MX5

      By The Bogan · Posted

      Seat of the pants assessment of the new intake: The car is way less "doughy" when hitting the loud pedal, especially off idle when stopped or in traffic, I did use a cheapo lazer thermal thingo to measure the temp around where the pod filter got its air, it was between 55 - 60°C, in saying this the car was shut off and not moving, so the OEM intake pipe was not supplying any fresh air to where the pod was when the car was at least moving A weird bonus was induction noise on the throttle in the cabin increased a bit,  I was worried that I was actually going to lose some of that induction noise I love so much, outside though, when I got the daughter to do a WOT drive by pass for me, the induction noise has increased alot when on the throttle, not quite ITB doort, but well up there I'm extremely happy with the results and have been exploring the country roads in the region  As for house mods: 1.New front fence is up and is awesome, it really upgraded how the joint looks from the street, and the added security is nice 2. Electricians have replace some interior lights, and with more lighting in the garage, a few new motion detecting lights out the front above the garage, front room, and at the front door, which I have already found heaps helpful coming and going, also now has fancy pants CCTV all round the house The only hold point for power though is the solar and batteries due to supply issues, although this will happen over the next few weeks 3. I have done a heap of landscaping out the front and I'm almost ready to do a new small retaining wall with some nice blocks to replace the brick and cemented in rocks around the raised garden beds cemented in river stone "was the fashion at the time" the house was built. I currently have a pallet of retaining wall blocks and 2 bulka bags of 20mm blue metal to replace the wood chip that is in the raised garden beds around the house 4. I now have 3 big raised garden beds for out the back to grow some vegetables, about 70cm high, 200cm long and 100cm wide 5. My 2 compost bins are already pretty full with brown, green and kitchen waste from the landscaping I'vedone so far, but they will probably take a few months to break down, so anything else that gets chopped, trimmed, and kitchen waste will just start filling the base of the raised garden beds to about 30cm before I start throwing 40cm of good compost, and stuff, for the vegetables to grow in, I'll need a few ton of compost and soil, but the local supplier can sent me bulka bags of the stuff Basically the logs, wood chips and a few strategically placed rocks for drainage, will give the beds some good organic materials down low to break down over time, and they will hold moisture during the warmer months to save the water in my big arse water tank if we don't get alot of rain So, all in all, the car and house mods are going well, and I'm really enjoying being retired, I sleep in too 0700 and slowly plod around inside until I feel like actually doing anything, and only work in the yard for as long as want, which has actually been alot over the last few weeks,  although when you look at it, it seems that not a huge amount of work has been done,  until I look at the before I started the work pics Happy days and good times indeed 
    • Dose Pipe Sutututu
      new 1.5 LSD issues/concerns

      By Dose Pipe Sutututu · Posted

      This everytime 
    • DraftySquash
      Looking for someone with a R34 front bar

      By DraftySquash · Posted

      hahaha yeah. Plan is to get side skirts and probably just rear pods. But going to do them one-by-one. I've got a set that I really like from RHDJapen, but that one isn't shipped to AU. So need to find someone who can get it for me
    • MBS206
      new 1.5 LSD issues/concerns

      By MBS206 · Posted

      Here's an idea, answer the questions I asked you as they are trying to work out WHY the LSD will be binding up in a straight line.
    • MBS206
      Most women will agree that parking is the most taxing part of driving

      By MBS206 · Posted

      You haven't driven many modern cars then have you? Most of them have sfa steering feel with their stupid electric bullshit steering systems.
×
×
  • Create New...