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Hey guys, i know that having your ac on does affect performance but with my car it seems to make a Huge difference. I have an 03 zx3 and i wasn't sure if this was normal or not. I try to drive without ac bc it drivers better and makes a huge difference with milage but its hot in FL so I can't always do that. Basically just seeing if this was normal or not and if it isn't if you guys have any suggestions. thanks!
 

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On a small engine wrapped in a light car the AC compressor will make a noticeable impact driving. It is rather annoying.
 

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Things that help this a good bit is a tune , 180 deg thermostat , doing this with a Tune can turn on the fans sooner and keeps the engine cooler , this makes for more performance and by having the fans on cooler it lowers the head psi in the compressor and makes turning the compressor easier meaning takes less HP from the engine to run the AC

Tom
 

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I can feel my A/C compressor kick in and out even when just cruising at a constant speed and RPM. Just the nature of a low-power engine getting hit with a big power draw.
 

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Yep, I was cursing mine today. They are dead with hot day and mileage over 125K. The ring seal has dropped enough by then to show effect. A brand new engine will motor right through that condition.

I was wondering today based on the response of the engine to throttle if there wasn't more a tune might do since the throttle gets opened up a bunch but nothing really happens. Get deeper though into it to hit the open loop and at a very small bit more of throttle boy it comes on then, like a turbo just kicked in. It has something to do with still trying to run at stoichiometric at lower load.
 

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I could see that happening there. Something is wonky when you can open the throttle 15-20 degrees and literally nothing happens. I realize the a/c steals power but the engine simply does not go with more throttle until you get way deep in it, then it suddenly DOES do right. That ain't right, something there in software that is correct with fresh motor is not once it gets old and less ring seal. Probably too hot and too lean for emissions, get richer and colder and boom! It goes then.
 

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some of the ac clutches have a washer behind them, but you can remove it when the clutch gets worn down.. doesnt hit as hard when it cycles.
 

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if you have an A/C system leak it can cause the compressor to bog down the engine
i have a fitting leak and cant keep R134a in my car more then a month
then my engine wants to practically die with the AC on
 

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Well, fix it...............

The clutch will stay on more for a little while but once enough refrigerant leaks out then compressor will be cycling off a whole lot quicker as the system knows when it's low. So, past a certain point it gets EASIER not harder. Below 25 psi the compressor won't even come on unless something else is wrong there.
 

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My A/C system in my foci is fully rebuilt 1 and 1/2 years ago, engine is healthy with no tune as far as I am aware of, after A/C rebuild I only notice the engine bogging down at idle as the compressor cycles on and off and when I put the hammer down for a short time (The ECU disengages the compressor during WOT and you can kind of feel it disengaging) If I drive normally I notice no difference with or without A/C.

Still not as nice as my Renault clio with just a 1.4, you don't even notice the A/C on at all except that it's making cold air... that being said it's not nearly as cold as what a healthy focus A/C will produce, I swear that thing was pulled from an industrial freezer, LOL.

If you have a leak and refill it with a normal over the counter Can you have moister in the system that will cause the compressor to work hard and eventually damage the compressor.
 

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Yes. Compressor works no harder, the water combines with refrigerant to make acids that eat parts up. Of course, if enough water in there to freeze across the orifice, then there will be problems there.

Putting oil in does more to damage the space relationship to refrigerant, the oil amount has to be exact, once you ooze out some unless entire thing is completely flushed empty then no way you can have the correct amount of oil, even a slight bit too much will tilt to less refrigerant and there goes the OEM cooling rate. I've found most cars have way too much oil in them after work and why they will not cool as well as a new car. After that it is the blower motor, you will never find a new one in ANY brand ever that passes as much air over the evaporator as a fresh new OEM one does and another big reason why older car does not cool like new one.
 
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