1992 LS400, 328K miles
The following was replaces at 300K miles:
Timing Belt, Idler pulleys, Water Pump, Crank Seal, Cam Seals, rotors,
Caps, Wire set, Spark Plugs
At about 327,700 miles the Left side ignition coil failed; replaced
both the left and right coils and that seemed to fix it. After driving the car
for a short time I noticed a slight shutter at idle, kind of like a miss fire. I
was getting 19 PMG but the shutter, kind of like a miss fire, got worse then
the check Engine light came on. I also notice a reduction I power.
Code 24: Intake air temp. sensor signal
Code 71: EGR system malfunction
The 12VDC plastic connectors to the Coils fell apart and replaced them
with Lexus connectors; the wire and pins were ok.
I have checked the following:
All ignition wires; all within specified ohmic values
Checked all spark plugs
Left and Right Cam Positions Sensors: Both within specified ohmic
Cleared the code drove the car for about 15 miles (still a shutter at
idle) when the Check Engine Light came on. Same codes. The car still runs
pretty good at cruseing speed but I’m getting about 19 MPG HWY instead of 25
A website discussed that a dirty throttle body could cause a Code 71. I
pulled the throttle body and it was filthy dirty. I cleaned it up and blew out
the passages. The engine started right up but it now runs rougher and idles
higher, 1150 RPMs, it used to idle at 650. I have driven the car for about 20
miles in this condition, no check engine light yet. I’m stumped. I welcome your
feedback, hits, tips and tricks.
Here I go with another good one lol ..... I recently puchased another Lex, this time a 1994 SC400 . When I first got the car, it drove fine . Then about a month ago, the check engine light came on . The DTC's # 25 & #28 indicated that it was running lean and that I have an 02 sensor problem ....Fast forward two(2) weeks, car is running fine, I go to the station and fill it up with gas; when I try to start it, it just turns over . I check everything and find out that I am not getting any spark . I pull the connection plug off of the right side coil to check for current . I had power, I check the other coil and had power there as well . So plugged the coils back in and the car started . It idled for about 2 mins and died . I had the car towed home, the next morning the car cranked up and ran just fine; for about 2 day's, and then did the same thing . I tried to retrieved some DTC's to help me fix the problem, but the check engine light wouldn't blink; and that's when I was given a clue . Whenever I tried to crank the the car, if the light would come on with the key, the car would run; but if it didn't come on, it wouldn't crank . I also noticed that when the light did come on, it would be weak, sorta flashing like it wasn't getting enough power ....That led me to checking my fuses and connection's . When I got to the underhood fuse box, I noticed that the fuel pump relay was warm, so I checked the circuit and found out the turn on wire was only getting about 4 volts . I ran a wire (ignition switched controlled) to supply 12 volts to the relay when the key was on . The car ran fine for two days, then did the no check engine light thing and wouldn't start .....Thinking that it was the ECM (since I couldn't go into diagnostic mode), I had the ECM rebuilt . When I got it back, the car craked up and ran just fine, but it idled erratcally . The RPM's would go up and down, from 1500 to 1000 . Other than that it drove fine with plenty of power . Then I noticed that sometime my RPM gauge and my MPH gauge wouldn't be working, then all of a sudden they would start to working again . I figured that the ECM must not have been built right, so I got another one, and I still have the same problem's; and now on top of that, my transmission isn't locking up . No let me rephase that, it is locking up, and then unlocking when driving . When driving at a steady rate of speed, you can feel it going in and out of lock up .... So far I have put in a new ECM, and a new fuel pump . I would really appreciate any help, feedback and guidance concerning this . I want to thank everyone in advance for your suggestions .