yodathespian87
New Member
I figured out the problem for charging guys. It was a fuse. Went to the junk yard and got a TPS off of a 96 SC300. Looks like they have the same part number but it didn't fix the problem. So not the TPS.
94 SC400 Misc. Repair
- Thread starter yodathespian87
- Start date
The 1UZFE EGR Delete Kit is available for sale here.
I have an opposite issue... no power to the box whatsoever, but if jumped to a 12v source, all functions work great. I get to tear the dash apart next week to find the short or i'll just wire up a new circuit.
I found that both of my fuse panels are a total mess. Incorrect spec'd fuses all over but once I replaced a few of them I got a lot of interior functions back like my teloscoping steering wheel, pwr door locks, dome lighting, digital clock and trip counter. I am finding that lexus uses a lot of "daisychaining" where 1 circuit feeds 5 others so wiring diagrams really help trace these issues.
My college has Mitchell on Demand on every computer. Its not as good as Alldata but it gets the job done. My friend downloaded Alldata off Bit Torrent for free. A bit risky, but its out there if you really want it.
yodathespian87
New Member
So it has got worse. I can't go over 40 miles and hours, soon as the RPMs hit 1800-1900 the engine seems to hit a kill switch until the RPMs drop under 1800. I noticed the timing belt suddenly has become semi loose. It flexes about an inch now. Anyone have an idea of what is wrong?
spf_lexus
Active Member
If your belt is flexing that much, I would start with a new timing belt. Early 1uz's are non-interference so if it snaps or gets too sloppy, you wont have to deal with broken valves. You could be experiencing excessive advanced/retarded timing and once you hit 1500+ rpm... the belt is streaching and throwing the timing out the window. Check the timing belt, timing tensioner and timing idler for wear and play.
I just bought a salvaged 92 sc400 and im dealing with a lot of electrical issues myself. The idiot who owned it before me had every fuse changed for incorrect values so stuff is popping everywhere!
Hey did you ever have to deal with a broken HVAC controller? If I jump 12v to the controller, I get all climate control functions but cant find out why it wont see power. I looked up wiring diagrams and it states there is a major junction block for the hvac controller and its the only tap/connection for the entire HVAC circuit so I know where I need to look, but cant find a diagram stating where this connection is located? I get a picture showing it located behind the cluster but there isnt anything behind it.
I just bought a salvaged 92 sc400 and im dealing with a lot of electrical issues myself. The idiot who owned it before me had every fuse changed for incorrect values so stuff is popping everywhere!
Hey did you ever have to deal with a broken HVAC controller? If I jump 12v to the controller, I get all climate control functions but cant find out why it wont see power. I looked up wiring diagrams and it states there is a major junction block for the hvac controller and its the only tap/connection for the entire HVAC circuit so I know where I need to look, but cant find a diagram stating where this connection is located? I get a picture showing it located behind the cluster but there isnt anything behind it.
yodathespian87
New Member
As for the broken HVAC controller I have yet to deal with that but it may be broken as my climate control has power to the diasplay but I have no blower what so ever. The only heat I get is when I'm driving I get a little, not a enough to do anything. And Nothing for my A/C as well. By the way where did you get your diagrams for the cars wiring?
As for the RPM issue. It deffinately needs work in the timing belt area, perhaps a tensioner. I was feeling the belt and it didn't seem like any of the knobs on the bottom of the belt were ripped off. It's been doing this since the day I bought it and that is before and after I changed the water pump and an idler pulley. The car sounds good when running so the timming may be really close and just not perfect.
As for the RPM issue. It deffinately needs work in the timing belt area, perhaps a tensioner. I was feeling the belt and it didn't seem like any of the knobs on the bottom of the belt were ripped off. It's been doing this since the day I bought it and that is before and after I changed the water pump and an idler pulley. The car sounds good when running so the timming may be really close and just not perfect.
spf_lexus
Active Member
I have an opposite issue... no power to the box whatsoever, but if jumped to a 12v source, all functions work great. I get to tear the dash apart next week to find the short or i'll just wire up a new circuit.
I found that both of my fuse panels are a total mess. Incorrect spec'd fuses all over but once I replaced a few of them I got a lot of interior functions back like my teloscoping steering wheel, pwr door locks, dome lighting, digital clock and trip counter. I am finding that lexus uses a lot of "daisychaining" where 1 circuit feeds 5 others so wiring diagrams really help trace these issues.
My college has Mitchell on Demand on every computer. Its not as good as Alldata but it gets the job done. My friend downloaded Alldata off Bit Torrent for free. A bit risky, but its out there if you really want it.
yodathespian87
New Member
My fuse box is/was all messed up as well. I will have to check that out. I'm on Bit Torrent already.
yodathespian87
New Member
So a buddy came by that is a mechanic, played around with the car a little bit. He ended up messing with the TPS and put the car in loop. Now she works great. So something is wrong with the TPS or something in that system. I was told not to drive it around cause it could mess with the shifting and I will get bad gas mileage. Figured this could help some folks as it has been plaguing me.
