Mechanics

I HAVE A SC400 . HAVE NO IDEA WHERE TO BUY REPAIR MANUAL OR PARTS. READ BELOW AND PLEASE HELP.

1994 Lexus SC 400 • 130,000 miles

Sc400 was running great. Then started missing lunging and dying, died after two or three starts, auto parts store recommended sea foam, due to us having a hard rain. I found clamps loose around air meter box, tightened them, and noticed a lot of 10 mm bolts missing which hold that box in place. Yesterday, it ran rough until I returned home, and the a/c only worked when the car ran great. Today, I found a broken vacuum hose fitting and attempted to fix it, but the car worked so bad, I towed it home with another car. The A.C had stopped, clutch was not engaging. However, after I backed it into it's parking place, and turned it off, I turned it back on, it ran perfectly, and the A.C was cooling again. I still need to permanently repair the broken vacuum hose, and replace the 10 mm bolts, and I suspect that the clamp near the throttle body was not tightened either. And it may need new plugs, possibly a new fuel filter, could be a fuel pump. I would say I have my work for me. What does all this sound like to you and why the A.C quitting as well? Do I need to undo the neg on the battery and reset the computer? I just bought it last month, and I think I have found a lot of the previous owners problems. I have a car fax, and there was two owners. Obviously, one or both of them did not care much for maintenance. Help me please
Avatar
Shadowboxer50
March 17, 2012.



Dont get all done in by a minor glitch. Fix the vacuum thing and any loose clamps and drive it if it's runnin ok.


Tiny
Fixitmr
Mar 17, 2012.
I repaired all of the vacuum leaks. I do not see any more. I removed the neg of the battery for five minutes. Started the car, drove around the block and a/c worked ok. Then all of a sudden, the car started missing, the a/c stopped, and it went dead. I got it back home, and I can remove the neg on the battery and re-install it, then the a/c works car runs great for about two minutes, then it dies. When I turn it back on, it is idleing much faster. And A/C does not work. Something is bad and the computer is finding it. I am not sure I can make it to the auto parts store in it to find the fault code


Tiny
Shadowboxer50
Mar 18, 2012.
Ok, we started it from a cold start and it ran terrible, we pulled in a shop. The mechanic put it up on the rack and went right away checking dual catalytic convertors, resonators, etc.
Then they started saying that the check engine light would not respond or come on at all. They were wanting to keep the car at 80 per hour and go into the dash. (I am not paying for an idiot light, that would make me the idiot) They claimed at first the car was too old, that they had newer meters, then they tried and older meter and claimed the ECU wouldn't keep flashing long enough for them to get the code. Then he started checking the coils, one was newer and had been replaced, the other was original, so he ordered a coil. $215, out the door and the car ran great. Until the next day. From a cold start, it takes three or four tries until it stays running, and when you go it has half power, running slow until it builds up speed. Then stopped at red lights it is idling higher, we pull over turn the thing off and go in a store or something and come back out, start it and it runs great again. After that, there are no more problems the rest of the day.

I am considering a plug job, and a fuel filter replacement and see if it helps. It can't hurt anything but my wallet, since I do not know when they were replace last.


Tiny
Shadowboxer50
Mar 29, 2012.
Do you have coolant losses issues?
Check the engine compression and let me know the results. Do it on a cold engine.


KHLow2008
Mar 29, 2012.
Ok, I had a compression testor, but since it is from the 70's, it has about had it anyway. No coolant lost. Put in the plugs, All plugs looked the same, carbon with no damage, changed fuel filter, and found two loose vacuum hoses. They are like hoses that just got hot and they are plugged on, but loose. I pushed those way on really hard. Car was running great for two days, and then when the fuel light came on, added gas. Then it went back to it's old way of spitting and all that stuff. The A/C will not pull in the clutch when it runs rough and the RPM tops 1200 at idle and then it starts skipping and running rough from 1200 down to rpm of 600. The other day, it cleared up on its own riding down the highway and we had really cold air all the way home. I had another shop tell me it may be the a/c compressor dragging things down. But I do not have the a/c on all the time yet. I am still leaning towards these old vaccum hoses and will not stop until I am sure there is no loose ones anywhere. I would probably pay $700 for another a/c compressor and then it still do the same thing. So, ruling out the simple things are for me. I love being under the hood of this car. Everything is in such great order. I like organization.


Tiny
Shadowboxer50
Apr 2, 2012.
Recheck the vacuum hoses. If there are loose, snip off the ends and reinstall.

I don't think you need a compressor. When engine idling speed is too low, the AC would not work. Since the problem affects the A/C, I woudl suggest checking the ECT.


KHLow2008
Apr 2, 2012.
Well, I have been busy moving. The place where I lived was a gang hood, I had two tires cut and slashed, and a neighbor had water put in her gas tank. My car runs great most of the time, with the exception of startups. Sometimes it will start up and rev up and then it runs with no power at all. We have just gotten used to turning it off, waiting a few mintues and then start it again and then it is all right, while waiting we smell gas fumes.
And that A/c compressor quit. The clutch engages, squeals and then with a thump it stops and the light over the a/c switch starts blinking. I know the compressor is locked, I see the clutch slipping on in trying to move it. Otherwise Texaco gas seems to make the car run a lot better


Tiny
Shadowboxer50
May 4, 2012.
Symptoms indicates a possible fault with the PCM or its wiring. It is intermittently not working correctly and restating sometimes solves the problem.


KHLow2008
May 4, 2012.
I got sick, and found out I have fainting episodes, or possibly seizures. So I have been away for a while.

The way all of this started, we have gotten used to turning the car off when it starts up and idles too fast, and the next time she runs perfect. It is intermittent. But now to the real worse problem. We will look for that first problem later, or may solve them both at the same time who knows?
We had the coldest air, until if got really hot. Then one day there was a squeal under the hood. I noticed that the clutch is pulled into the compressor, but a large center piece with a bolt in it is not turning. It tries intermittently and this is what makes the noise. I put my gauges on it, and of course the compressor is not pumping. I took a large screw driver and the end of the clutch is like a magnet making the driver stick to it, however the cent part of the hub with the bolt in it will not turn, it appears to be broken off of the clutch, Could this be the case and I just need a clutch, or is it possibly a new compressor. Makes me sick knowing it is so hot and I am so sick. I gotta have it cooling. The belt is ok and it all is turning, just not the end of this plate with the nut in it.I feel like that bolt and plate is what turns the compressor and makes it pump. Anybody?


Tiny
Shadowboxer58
May 25, 2012.
Page 1 of 3