HELP!!

[ajfsgrl08]

Hi my name is Lynne. I oun a 99 Subaru legacy. I have been haveing some power issues with it. We've changed the fuel filter, timing belt, plugs wires(NGK) and coil. However the car runs great until you turn the AC on!! We've run a diagnostics test and nothing comes up. If anyone has any ideas or sugestions please share!! Thank you :smile:

Lynne

[decke48]

well my guess is the a/c compressor might be semi-frozen. or has a big restriction in the high side of the a/c. if you have a set of a/c gauges see what the pressures are when the clutch is engaged and spinning the conpressor. to see if the compresser is frozen you need to loosen the a/c belt all the way and see how hard it is to spin the a/c clutch

[Reason]

How bad of a power loss? I had a 97 GT (2.5L) auto and now have a 98 L (2.2L) 5 spd and both lost power with the AC on.

[Sarra]

I don't have AC, that's my problem. :( Blows hot air...

[Lemanschamp]

well my guess is the a/c compressor might be semi-frozen. or has a big restriction in the high side of the a/c. if you have a set of a/c gauges see what the pressures are when the clutch is engaged and spinning the conpressor. to see if the compresser is frozen you need to loosen the a/c belt all the way and see how hard it is to spin the a/c clutch


+1000

[ajfsgrl08]

This is Lynnes boyfriend.

As my girlfriend said, I have changed the plugs (installed stock NGK single platnums), wires (also NGK's), fuel filter, timing belt, adjusted the valves, and the coil.

The car ran great when she baught it @ 103K miles. It kept running worse and worse. Along the line I changed the plugs/wires/fuel filter. This fixed the problem for about 100 miles, then it ran like crap again. Next I changed the timing belt (original one @ 105K :shock: ). The same result was had. Then I changed the coil. The car seems to run good without the A/C on. With the A/C on, the car idles just as smooth as can be.

For anyone that has had a coil crap out, they know how the car bucks and shudders under acceleration, that is what the car does now with the A/C on.

Just before the coil was changed she was getting about 230 miles on a tank of gas. Now she is getting about 400. However, the gas guage doesn't work properly, it reads empty after just 300 miles. I took a gas can with me alittle while ago and ran the car out. It ran out at alittle over 400 miles; atwhich point the needle was 1/4" under the empty mark.

Now, back to the coil change. I replaced the coil with an OEM replacement from Advance Auto. BWD IIRC was the brand. Do Subaru's like or dislike certian brand electronic parts as they do with the plug wires. I would like to put an MSD coil on it, then atleast I would know that the coil isn't the problem, I just blew $105 on that coil though and don't really want to change it unless it is the problem.

The part that kindof confuses me about changing to an MSD coil is the fact that the coil on the car uses a 4 wire plug, not a 3 wire like in the "Neon coil" write-up. :wtf: Is the car just an oddball?

[Reason]

Subaru likes to use left over parts so depending on if yours is an early 99 production you have some 98 parts and if a late 99 you may have some 2000 parts. On my 97 I had parts from 96,97 and 98 but mine was an early production. Also they used 3 different types of PS pumps.

As for being finicky about different electronics I just know about Bosch plugs. Notice the car had rough idle and bad gas mileage. I thought it was normal for a Subaru till I switched to Denso plugs (my old 97GT). I have NGK Iridium's in my 98 right now no issues. I'll switch to coppers next time to see if it helps any. But for the most part the idle is smooth.

All 3 Legacies I had did the same thing. But who's to say they all are like that. That's just from my past experience.

I believe that the write up tells you what to do with the 4 wire versus the 3 wire. Pretty much read through the whole thread and you will find the post.

[subba]

i have a similar problem going on right now, the A/c works but once the a/c is on the crank feels like its trying to sping and the compressor is slowing it down... which i came to the conclusion it is because the car literally shuts out when i am try to move off from a complete stop.

[decke48]

well it takes about 20hp to spin the compressor but it will kick up the idle to compensate for it. the 4 wire coil packs use a "driver" in the coil pack adding a ground for the ecu to monitor. 1997 2.5(some), 1999 2.2 and late model 2.5 use it 2000+ std on all motors. as far as i know theres no way around it. i'd still try this to rule some things out

Originally posted by decke48:
well my guess is the a/c compressor might be semi-frozen. or has a big restriction in the high side of the a/c. if you have a set of a/c gauges see what the pressures are when the clutch is engaged and spinning the conpressor. to see if the compresser is frozen you need to loosen the a/c belt all the way and see how hard it is to spin the a/c clutch

[ajfsgrl08]

Well, frankly Lynne's former car (1992 Legacy L, 2.2L FWD) had more power than her '99 does right now.

Just seems alittle odd.

[Reason]

Maybe the compressor is going bad. Try that I guess, you also didn't change wires yet either. Not that I think it is that but you did the plugs and coil already. What about checking or upgrading your grounds?

[Huffer]

I second the possibility of a semi-frozen AC compressor. Mine does a similar "surging" when the AC is on and I'm just cruising. It's almost like the AC kicks on and off every 10 seconds. Doesn't affect overall idle or cruise speed.

My AC didn't work for about 8months. Then one day it switched back on. I took advantage of it and recharged the system. But I have a feeling the system will need replacement next year.

[ajfsgrl08]

Today I did an oil change and also changed the plugs. I put NGk single platnums in about 1,000 miles or so ago, and after changing them and putting NGK V powers in to day the car runs a good bit better.

BKR5E-11 :smt023