| Author | Message | ||
     James Feller Experienced User Username: james_feller Post Number: 13 Registered: 10-2007 |
Hi All, Bill, Richard, David et al.... or anyone else for that matter with an objective mechanical opinion. I have had differing opinions on this and seek some advice from you RR Scholarly people! When starting up either from cold or hot should the air cond/climate controls be switched off? My 86/87 Spirit does not have an economy setting, which I assume means the compressor is engaged or ready to be regardless of which setting I have the switch set to. The compressor will engage and disengage as requeired by the thermostats and positions of the temp rotor dials. You can hear a faint click on and off as the system requires cooled refrigerant. Economy I assume means systems and fan run but compressor won't... Anyway, I have tried both ways and certainly from cold the engine fires and settles far more quickly say about 3-5 seconds with the systems turned off. When hot I must confess to forgetting sometimes to turn the system off but this does not seem to have much effect on hot starting, the engine fires and settles down quickly. thoughts, whats the best for the system? | ||
| Paul Yorke Prolific User Username: paul_yorke Post Number: 103 Registered: 6-2006 |
Hi James, The compressor & fans shouldn't cut in until oil pressure is achieved, although this can be with cranking with many cars. I suspect the fluffy starting may be due to slightly lower voltages which would be affected by the Air Con being on. The battery level is usually higher after the cars been running. Also an engine tends to start better when hot. In theory it should not matter if the A/C is on or off when starting and will not cause any damage either way, but - as you answered your own question - it will be happier with it off. On your car, unless modified, the A/C should run constantly. Even when full heat is asked for. There are exceptions - Air intake to A/C matrix less than 0 degrees will turn off the compressor. (low system pressure, high system pressure,oil switch reading low pressure - will all switch off the compressor as well. These are mainly faults though. ) | ||
| James Feller Experienced User Username: james_feller Post Number: 14 Registered: 10-2007 |
Ta Paul, I suspected this was the case but I was told emphatically by an Auto A/C person some years ago to make sure systems were off on start up as it puts 'huge strain' on the engine and componentary?? Logically however if you consider this it does not seem to make a great deal of sense as the only strain would be on the belts and starter motor till the engine fires? plus as you say the battery, did not think of this part. Huge strain, what is the engine 6.75 litres for if it cannot handle the A/C engaged while cranking??? or for that matter 2.5 tonnes of Roller it has to move! Certainly while under way there is no discernable difference in performance that I can feel with the compressor cutting in and out as it does what its meant to do. Only if your stationary at lights or idling in traffic can you hear it lightly cutting in or out anyway and this is only by way of a soft clicking, if very hot conditions the thermo fan at the front wirrs away too plus the revs drop or increase a bit. To my knowlege the car is as it came from Crewe destined for Aus 20 years ago so I suspect all is as it was designed and 'unmodified'. I must say the system is very good for a car that is 20 years old, true it has now had a new compressor fitted with the R134a gas some years ago but it is a most effective system considering its age. I never feel that it is underpowered, certainly cooling is tremendous, if you have a window open in this humid weather the bullseyes quickly become condensated and a light film of ice forms on them. I have never really needed to move the dials much into the blue section with the AUTO function on in most cases. Anyway, just interested to see what people think. Cheers James | ||
| Richard Treacy Grand Master Username: richard_treacy Post Number: 1317 Registered: 4-2003 |
Your compressor has two basic inhibits among others: 1. When the starter is cranking, the compressor will not engage 2. Until the oil pressure rises, the compressor will not engage There is no need to touch the climate control selectors ever. Mine is a later model but essentially the same functionally, and I have not touched mine in 10 years, except on the rare occasions I have selected DEF for a minute or so on a frosty morning. RT. |
