ok I have a big problem with my 94 H23 Si lude. It is running extreamly rich to where it is going through gas twice as fast as it should. At about the same time this started the AC will not blow cold but it will blow hot. The weird thing is though the check engine light is not on. Recently I had the head gasket replaced, the head was completely remachined as well...

 

check your MAP sensor connection. That could be the cause for the rich fuel mixture. AC not working is probably unrelated. Does the compressor engage?

 

what do u mean by engage?

 

as the AC system operates the compressor cycles on and off. if you look at the compressor while the AC is running you should be able to see the wheel on the compressor turning when it is engaged and not turning when it is not engaged. Additionally you should be able to hear a click when the compressor turns on...this is the relay actuating. Correct me if I am wrong guys..

If you have a service manual there is a trouble shooting guide for the AC system that is pretty helpful.

 

the wheel on the compressor is spinning... I found a hole in one of the map sensor vacuum lines. could that be my problem with it running rich?

 

Yes definately. There should only be 1 vacuum line that runs to the MAP sensor. If there is a hole in it the computer is going to be seeing a MAP equal to atmospheric pressure. Thus, the ECU is getting a signal from the MAP sensor like you are at WOT all the time even though you are at not on the gas. As a result the injectors are spraying a large amount of gas and causing an extremely rich mixture. I think if you fix the vacuum line you have fixed your rich mixture problem.

Now for your AC. If the compressor is running then you might just be low on refrigerant. If you have the proper gauges you can look at the high and low pressure sides of the system. If all your refrigerant has leaked out then air will be in there. You will need to find the leak, fix it, and then recharge the system.

 

first off, thanks so much man.
second, also when i turn on the AC the engine revs up and down.

 

Wow.. mine does that too... I'll have to watch this thread.

 

a bouncing idle can be caused by many different things. FITV, IACV, vacuum leak etc. Mgags7 put together a nice thread addressing this problem. Link below

https://honda-tech.com/zerothread?id=1979500

Read through that and see if any of that helps. Are you saying the idle only surges when the AC is on and is fine if it is off?

 

yes, the idle only surges when the AC is turned on. It gets worse as I turn up how hard it blows.

 

anyone.....