hello steve
steve my 92 190e 2.6 A/C was converted to r134 the only thing
i change was the receiver drier as long as i'm driving the temp
gets as low as 43to41degrees but when i'm not moving the A/C
gets hot i have 2 new aux fans new fan clutch i didn't flush the system as it was empty i vacume it for 1hr any suggestion
as to get to satay cold at idle if i spray the avaporator with
water while at idle i get it to stay cold.thank jose in daytona beach.

I have the exact same car. I am still using R12 as R134 is not as efficient. The condenser (in front of radiator) is really limited in it's ability to dissapate the heat. Mine was also weak at idle and I also replaced the fan clutch as mine was weak after so many years. This helped some but still not good enough for the hot humid summers in slow moving traffic. I ended up designing a circuit (electrical engineer) to pull in the aux fans at idle only to increase air flow accross the condenser. This works much better. I think that the switch to R134 really hurt your AC performance. Good luck.

Rod

the minute i spray cool water on condenser. the temp goes as low as 38.degrees and frost smoke comes out of vent.
also the only way i could stop the compressor from cycling off and on continuely i had to take some freon out of the system
but it still cycles off&on to fast.

I'm not Steve. As a matter of fact, I wouldn't make a wart on Steves neck, but I might can offer some help.

Yes, the fan clutch must be in good shape and will probably be more important for this than the aux fans. The aux fan is triggered to bring down high side pressure to prevent system damage, not necessarily to aid in the a/c system operation.

As Rolf said, the a/c in these cars are marginal in capacity at best. Since you lose about 20% of system capacity when changing to 134 you are on the edge of adequacy. If the conversion is not done correctly, the loss in capacity will be even worse.

There are different pressure switches available for 134 use. This will change the cutout pressures to be more favorable for 134 use. Since I have never converted a 201 or 124 car due to their marginal capacity, I don't know where to get such switches.

If the car were mine, I would thoroughly flush the system, replace the filter drier, dump as much oil as I could from the compressor, pour some mineral oil in the compressor, turn it a few rotations and pour it out, then put in the correct amount of mineral oil, evacuate and charge with R12. In other words, clean up the system and reverse convert.

You very easily could end up spending more time, money and frustration trying to get the system to perform to your satisfaction with 134.

I've seen a number of 134 conversions that were done at greater expense and trouble than simply repairing and staying with R12. All that is done and the system has no chance to cool as well as it did with R12.

Best of luck,

I like an air conditioning thread where all the guys posting are in hot humid locations... .... makes it more real...
There are new condensors in the newer style( crossflow) availalble which may help... and when your system is empty during work is the time to conside upgrading ....