aircon

[heibermann]

Hi ppl

I am new to AF; in fact this is my first post. Having read the majority of the newbie FAQ threads and also searched the other threads, I am confident that my question has not been asked (much)...

I have an aussie spec '98 S14A 200sx (i think you guys would call it a kouki- ?)

It has the SR20DET blacktop with variable valve timing etc and is a 5 spd man. Mechanically, it is in completely stock condition.

I noticed that shortly after the last dealer service, it dropped in power significantly (as detected via seat-of-the-pants performance meter). Initially I put this down to a change of weather, but this made no sense as it was getting colder- should be making more power. Then I threw in some injector cleaner- made no difference.

Conundrum starts here-
Yesterday I began driving to work, and then I turned on the airconditioning (largely unused during the previous few months due to winter- except once in a while to keep the gaskets/seals in good condition).
Lo and behold- my car is performing (accelerating) waaay better (as I remember it used to), but only when the AC is turned on!

So the question is- Why would turning on the AC give me better power than with it turned off?
This never used to make any measureable difference, but by my reasoning it should have less performance with AC turned on..

I experimented with it again today and found the same results.

A consequence of the car being aussie-spec is that it didn't come with a boost gauge as standard ("How primitive" you say), and I haven't installed one yet so I don't even know what boost it is running with/without AC on/off.

My only guess is that it is something to do with the ECU (I think it would change maps for AC on or off, because my idle speed changes when I turn it on/off)- just a guess.

Has anyone- ever heard of this problem before? and
Does anyone-
-know the cause?
-know how to fix it?

Sorry if this is long-winded, next time I'll cut to the chase...

-heibermann-

[SR20DETpower]

i couldn't possibly see how that would do anything... and anyhow a/c only robs like 2 horsepower.

man but if u say its the a/c, I will throw something out into left field...


by some chance maybe the A/C compressor is locking up, with the A/C turned on it could let it flow better and move the belt quicker, however in reality its actually the opposite way around...

and if that was the truth you would hear all kinds of squeeling noises from the belt.

check out the A/C compressor since thats the only thing associated with A/C that could possibly affect the engine somehow

[Pavlo]

ok, just thought about it for a while. When the car is on and you turn on the AC the RPMs raise so the ecu is giving it more fuel. When its off it works normal, so if AC is off then it might give the car less than it should fuel resulting in power loss, but with ac the fual is at correct amount. If you did not understand please don't dis me, my english is not the best and I can't really explain it in my language either. If someone got what im saying please explain if you can. Also this is NOT sure the reason this what I think (it might be the ecu) so correct me if I am wrong.

[vsiev]

if ^^ what he said is true about fuel, maybe you got a clogged fuel filter or something. I don't know if it applies to sr20's, but I would go with the 300z tt fuel filter off a 96. It is like 10 bucks and it helps. Give it a shot, doesn't hurt at all.