I just finished transplanting an r134a A/C system from a '94 pickup into my '92 (3vze). I was pleasantly surprised that the wiring harness was already set up for the A/C. The A/C is currently blowing ice cold at highway speeds but is blowing somewhat warm air at idle. It has been holding a charge with no known leaks. I used a new condenser, compressor and dryer but pulled an evaporator and housing unit from a salvage yard (good condition). All new parts were OEM Denso products. Did not replace the expansion valve (probably should have). I have also noticed that the engine idles rather low at 500rpm with the A/C on. I did not install any sort of A/C idle up and the engine does not idle up with I turn on the compressor. Does anyone know if this low idle speed could be causing the A/C not to blow as cold at a stop? If so, is there an A/C idle up valve I should be looking for? How does the engine compensate for the extra load of the compressor?

Thanks in advance,
David

 

Like you said: the A/C idle up is there for a reason. i always thought it was to keep the A/C compressor from killing the engine, but I'm sure that running at 500 rpm isn't going to produce a lot of cooling anyway.

If the harness for the compressor and cooling unit are already there, then the lead for the idle-up VSV should be as well. There is some induction plumbing that runs under the plenum (to get unmetered air for the VSV to run into the plenum), but you might already have that as well. So you just need the VSV.