I recently acquired a 87 240 dl which had a weak a/c system.I have changed out the reciever/ drier and pumped down the system prior to trying to recharge it , the system held the vacuum but will not take the 134a. I have tried hot water etc.but it will not suck. The compressor will go on when I jump it and the pressure is high on the low side. Once it reached 90psi i stopped the procedure. I then checked the high side and it wasn't much higher 105psi. The ambient temp is 65F, but I have worked on my 740 with an orifice tube and the system didn't behave like this. Could it be the expansion valve that I understand is temperature controlled or what .I appreciate any and all comments. 240dl 148k 87, 740gle 16valve 149k 90.