Honda Fit AC woes, stumped

Recently obtained 2012 Honda Fit 150k miles.  AC not working, compressor kicking on then off quickly, about ten to twenty seconds later, kicks on then right off, repeat.
Dealer said A/C compressor was shot, so I changed out with new compressor and recharged to spec.  Still the same results. I look at AC pressures low side, once it gets to 35 PSI, the compressor kicks on for a second or two, the low side ac pressure drops to Zero the compressor turns off, then slowly climbs back to 35 and the cycle repeats.  High side stays right about 140 with little to no change when the compressor kicks on then off.  I figured blockage in expansion valve or evaporator on low side, so I replace evaporator and put new expansion valve (PITA tearing the blower motor assembly etc out but got it done),. All proud of myself, must be fixed! Nope, same thing, charged to spec, low side gets to 35 PSI, compressor kicks on, drops to Zero then compressor disengages and low side gets back to 35 psi, same cycle over again..... What am I missing? Condensor blocked? The fans do kick on when the compressor engages but stop once pressure reaches Zero on low side.   AC relay checked good, pressure sensor has continuity.  Could this be an ECM problem? Suggestions please, boiling here in Texas.  

I would say that you, definitely, have a restriction, somewhere. Be it a clog inside the system, or a crushed/crimped line.  Do a good visual check, paying attention to frost/condensation and line temperature change. If you have a restriction, there may be a line temperature change in at place that you would not, normally, expect one. The pressure drop across a restriction can act like and orifice tube or TXV, causing frost/condensation.

If a visual search found nothing, I would disconnect lines, where possible, and blow some air through.

Could this be an ECM problem?

I don't think that there is ANY way that this could be a ECM problem. The compressor is trying to suck more gas than it can get.
 

Visually everything looks good, the compressor doesn't stay engaged long enough to determine any temp changes in the lines. Looks like there is only one pressure sensor?

new compressor and recharged to spec.  Still the same results. I look at AC pressures low side, once it gets to 35 PSI, the compressor kicks on for a second or two, the low side ac pressure drops to Zero the compressor turns off, then slowly climbs back to 35 and the cycle repeats.  High side stays right about 140 with little to no change when the compressor kicks on then off.

I'm curious how you recharged the system. Did you charge on the Low side or, the High side? Was the compressor kicking on when you charged? How did the High side get to 140 psi? Did it slowly climb to that, after a few compressor cycles? If you shut the vehicle off and let it sit for a long enough time, do the high side and low side pressures equalize?

charged through low side port as much as it could take before starting engine, using can and short hose, bled the hose first to clear any air. then turn on engine and fed the rest, only takes 14 oz. pressures do equalize when shut off.

Well, I've come this far, just unloaded the parts cannon, ordered new condenser and new suction/discharge lines and pressure sensor via Amazon grand total $199 out the door. I pulled condenser, it's original looks like some silver slurry in the ports! guessing previous owner had Black death, grenaded compressor? I will have a whole new ac system at this point, peace of mind, I will update when I get the parts installed.

 

Woes no more, I installed new aftermarket A/C Condenser and I was able to source A/C manifold set from salvage yard $75 because the set from Amazon wasn't complete (lacked some of the aluminum piping from condenser to evap and another short piece on low pressure return line from port to evap), I flushed the lines, they were much cleaner than original, no black soot, installed new o-rings, lubed them, evacuated for about thirty minutes and recharged, freezing me out now. The other day, I called my local Honda dealer for new evap core, they wanted $750 and expansion valve $201, I said no no no, I need only the evap core not the whole HVAC case, he's like I know it's $750, hahaha, I ordered EVAP core from local salvage yard and when I picked it up, they gave me the whole case $100. I loved the challenge, I'll sleep better knowing everything is up to par.

ron.r wrote:

Woes no more...freezing me out now.
 

That's great! Thanks for the update. Be cool...you deserve it!