Jim Van

1st owner took very good care of the car, timing belt and water pump were replaced at 80k, not sure if by design or was leaking and took care of it at the same time. Glad my assumptions were on it, but as my luck always is, never simple shade tree projects, always the 3 day projects (well at least for me).......

1990 LS400, had no heat the other day, and water reservoir was empty, filled both the engine and reservoir, waited till today, good sunlight and time to inspect. After inspecting upper motor, firewall where hoses come in and out, water valve on firewall and from underneath, only place what is coming from is small hole above crank shaft. Assuming that means water pump is about ready to go, but looking for confirmation of my assessment. Also with a 151K on it should I do the timing belt at the same time? If not wp, as I think, what could it be? Thanks in advance, Jim

Alexander, Thank you, only get code 21, was told by Lexus that means the A/C control assembly is the fault, bought one off ebay and still has the same problem. Again Lexus pulled out its problem matrix and said ok, guess I was wrong on that one, try the power transistor and by golly for 170 dollars he could get me one.....might wait now till it cools down some and see if all starts working again maybe the Evaporator Temperature Sensor Circuit is cheaper. The good news is given it has been in the high 90's having the A/C blow on high all the time is not a bad thing. Jim

I have a 90 LS400 A/C control, works but, LCD is starting to fade by the clock. Will sell for $70.00, much cheaper than what they are going for on Ebay. 757-358-3567 ask for Jim

Alexander, did the power transistor fix your problem? Having the exact same problem and Lexus wants over $150.00 for the part. Where did you get your part and if don't mind, how much did you pay? Also do you still have the diagram that you posted on 9 Jun 08. Thanks, Jim

Found the problem and replaced bad o-ring. Please close this post

wwest, Thanks for the web site, have been to them before when I first had A/C repaired, that is how I learned about the EPR valve, realized it when I went there just now. Have my download from that time, but not quite as detailed as the Hoy Fox web page was. Will take what I have with me when I remove the fans and continue tracing the dye and see if that helps. I hate not know for sure what to order, usually I find out that I missed something when I am 8 feet deep into the 12 feet job......

A 24 hour subscription to techinfo.toyota.com will give you access to all the documentation you need. Why the LARGE font, are you implying that most of us need reading glasses..?? Not my intent, but you have to admit it is easy to read.........compared to this font. Thanks for the web site will give them a try.

Does anybody have the Air Conditioning Diagram for a 1990 LS 400 or know where I can get one? Used to be able to go to Hoy Fox Lexus parts page, down load diagrams of everything about my 90 LS400 and use it to order replacement parts. A/C started blowing warm again, I ran the dye through it and believe I found the spot. Just to be sure, I really would like the parts diagram that shows all the hoses and in between parts (receiver/dryer, etc) in order from me to order the correct parts. My main concern is that I have not missed a hose/connection that is routed through an oddball location. Thank you in advance!!!

I agree about the minivans but they did not equate the two until I spoke to them this morning and they agreed with the rest of us, what is the use of this part on single unit A/C? Well back to my tale, grinded a BIG NOTCH in the small side of the piston put all back together and it leaked like sieve we assume through the torn rubber skirt we saw yesterday (through a factory made hole in the upper bell housing of the EPR no idea why this hole is there). Good news is it blew cold air until the mechanic turned it off because he was concerned about running out of Freon........so we assume the work around is to grind the notch into the piston in the EPR and let the expansion valve do it's job but with the tear in the rubber skirt we cannot stand behind our judgment 100%. Going to the “you pull it yard” tomorrow and if I find an EPR with good rubber skirt going to notch it and run it, what is the worst that can happen kill my compressor? From what I have seen on this forum seems like my compressor is a dead man walking anyways because of the EPR so might as see if I make it a slow walk or a full out run........

Ok, still waiting on my 90 LS400 to come out of the shop. 8 days counting today, I finally went into the shop and asked what the heck....not so nicely....and I was told this EPR was something they have never seen before and they did not know what to do. Now to give the history, bought the car for 1k (which was steal actually) and had Lexus do the pre-sale inspection and the only failure was the A/C did not work no other black marks on the report. Now the guy I bought it from already purchased the compressor which was still in the box in the trunk (hence why I thought for 1k the deal was to good to be true). Now I had my guys install the compressor, expansion valve, dryer and convert to 134a. Called them on Thursday as they requested since the parts had to be ordered and was told tomorrow for sure, called on Friday and was told tomorrow for sure. Well I into the place and the guy showed me the EPR and asked for my permission to open it up and see if it is plugged up and the cause of my A/C not blowing cold. Ok, we opened it and yep it was full of the remains of the original compressor so we dismantled it all the way down and cleaned it up. As we reassembled the EPR we notice the rubber skirt was torn about 3/4 of an inch. Well the Lexus dealer here parts department is not open on Saturday (just my luck) but I said put it in and if doesn't work I will go to AutoZone and get a new one (hahahhaha). Put it back together, installed it, charged the system, started the car and hit the A/C switch with our fingers crossed. Well low and behold the A/C blew cold my mechanic was smiling ear to ear because he finally got everything to work. That lasted all about 10 seconds and than the A/C started blowing warm; he cycled the A/C on and off with about 5 seconds in between and the A/C blew cold and had pressure on the Freon gages. Now when the A/C started blowing warm the pressure gages dropped to zero so we believe it is the EPR. Since this is a singe evaporator system what will happen if we gut the EPR and hook everything back up? Will it cause major failures or will the A/C work but I will get A/C "groan" when I shut the car off after driving with the A/C on? If I must have a fully functioning EPR does anybody know where I can purchase one? (besides the dealer and the junk yard, ebay is part of the junk yard since I cannot find one new). Thanks, Jim