Hello everyone. I am having an issue that I hope to havesolved soon. I know idle issues have been posted before, but I feel that this is a unique problem as I have gone through forum after forum. If I am wrong, and you know where to locate this issue, please clue me in.

99 civic cx
Obd1 H22A with B18B1 transmission.
Converted obd2b to obd1 and everything has been properly pinned (except for the IAB).
Engine is running strong and all is well until the airconditioning comes into the mix.
Idle has been set, and there are no vacuum leaks. Whenthe a/c kicks in, all is still fine until I rev and let it drop back down. Thiswill also happen when I am driving and shift back to neutral. The idle will dipway down to almost a stall. The engine will eventually recover and the idlewill sit normal until I do either of those again. This will repeat and sometimestall. When driving, it is not an issue. This is the only mystery/problem Ihave left.
Here is what I have done so far:
*Changed the ignition from internal coil, to external MSD.
*new IACV
*remanufactured a/c compressor
*deleted FITV and has not posed an issue so far.
*remanufactured alternator (which has been tested forproper voltage) *map sensor (junkyard part, but improved engine performancewhen a/c is not engaged) I was using the old D16Y7 map, which made it run alittle odd, but not bad.
*new fuel pump (99 civic si)
*ELD (junkyard part that didn't change anything).
*I have blocked off the EGR (which throws a code on theP13 ecu, but otherwise hasn't affected anything).
*code for o2 sensor heater. Not presenting a problem...I don't think.



I am also going to post this over in the prelude section.




So that is the meat of it. I really hope that there is ananswer somewhere out there. It is hot out here in Virginia beach, and I wouldlike my a/c.

Thank you.
-Jason-

 

First thing to consider is does the condenser fan work? If the condenser overheats, the compressor has to work against an abnormally high pressure and that will bog down the engine.

You could try opening the air screw some more. Open it until just before it starts to exceed the proper idle speed with A/C and everything else turned OFF.

 

mK378. Thank you for the response. The condenser fan does work, but it is a slim fan and it is only covering a large part (8" diameter) of the condenser while the edges aren't being cooled at all. My plan is to buy a larger fan that can properly cool it, but have not done that just yet. With this engine I am limited on space for a fan because the a/c lines are right in the way, almost touching the header. I think that in order to fit a larger fan, I would need to have custom a/c lines made but nobody around here will work with aluminum lines. That makes a lot of sense with the compressor needing to work harder. I adjusted the screw to bring the idle up to about 980, and that didn't help. The idle is fine as long as I don't touch throttle. As soon as that happens, the bouncing idle begins.

 

Maybe you overfilled the A/C system with refrigerant? Or the header is touching the condenser?

Post the high and low refrigerant pressures with the A/C running on MAX/recirc with the idle speed held at 1500 rpm.

 

Did all of the above and my readings are:
LOW: 25
HIGH: 275-325 (bouncing)

 

The header is about 4" away from the condenser. I also changed the fan location. It's now mounted on the front of the condenser. That didn't help, but now there is more room to work.

 

What was the outside temp when this was done?

The fan should be located between the condenser and the engine, and it should blow air toward the engine.

 

About 94°

 

So if the fan is on the outside, blowing air toward the engine, will it cause an issue? I understand that between the condenser and the engine is where it should be, but will it really make a difference? I could really use the space. Lol

 

Is the compressor staying on steady while it does this, or does it drop in and out? Do you have the compressor relay wired through the ECU like stock?

 

The compressor is staying on like a normal cycle and everything is original wiring (aside from jumpers) with no harness modifications. I had the shop evacuate the refrigerant from the system last night and took it home to start troubleshooting. I vacuumed the system down, but my HIGH side needle wouldn't reach the peg on the gauge. It did read below 0, and the low side held 26hg. I closed the manifold and left it for 20 minutes. No change in pressures. Could the high side be clogged? I was going to disconnect the fittings to the evaporator and try to blow compressed air through it to see if it flows freely. Then vacuum it back down.

If the needle doesn't hit the peg on the high side, does that mean anything specific?

 

By plotting your data on the service manual chart, you would see that both the high and low side pressures are way too low.

 

Thats not how you clean the lines out, you need to remove the line and use a detergent THAN use the compress air to remove all of the detergent.

 

Fixed.

In addition, the compressed air used to blow out the solvent MUST be DRY air. Moisture is the enemy of the A/C system.

 

Lol

 

This problem is bothering me so damn much! I want to just pull the a/c out and be done with it, but that is the easy way. One a brighter note: my wife's Honda Fit had a bad compressor clutch. Replaced the compressor, receiver dryer, pumped it down and recharged it. At least her and the kids will be comfortable now. A/C is taking over my life XD

 

As mentioned, do not use detergent, you should use A/C flush and the flush should be cleared using nitrogen, [dry air will work, just not as good as nitrogen], the compressor would need to be pulled and manually flushed out.

Also the gauge needles not pinning indicates a leak, and because it holds vac. at those positions point to O-rings as the problem, or possibly just a poor vac. pump.

Both high and low side should pin, if pump is good and no leaks. 94