Hi I folks, thanks for the read! I have a 96 LS I replaced the...
-Spark plug wires
-distributer caps/rotors
-timing belt/ tensioner and bearings.
Afterwards I'm getting random cylinder Misfires on 3, 5, 6
P0300
P0303
P0305
P0306
It runs like poop, Trac control is blinking, and heat isn't working even after warming the car up. I hear a tapping from the distributer area as well, but not from the head of the engine. I truly think timing was setup correctly, and It may have been a simple mistake while reinstalling the coils, wires and distributers. I want to make sure my engine isn't blown from the job, but I'd imagine there would be some racket if valves were bent no?
Here's a link to a video showing the timing marks after installing the belt and giving it two rotations. https://youtube.com/shorts/SU_MBVadeVY?feature=share
What are my best options to go about this situation. I'm stumped and have rendered my dream car as undrivable. If I messed up my firing order, wouldn't I have an even number of cylinders missing? If a coil was unplugged accidentally wouldn't 4 cylinders be missing, not just 3?
Thanks for any replies!
I don't have any experience with timing belts, however I have some ideas.
You changed a lot of parts at the same time, so you'll need to reverse check your work again. I watched the video, and to me it still sounds like a timing issue. However, it may just be the coils or a distributor problem.
Google: 1996 LS400 Multiple Cylinder Misfire After Timing Belt Replacement
I would check out the following sites:
https://www.fixya.com/cars/t2149725-timing_problem
https://us.lexusownersclub.com/forums/topic/7118-random-misfire-5678-help/
Here is another site listing a number of similar issues/solutions:
Thank you so much! I appreciate the fast reply. I have just always thought if the timing was off there would be some binding while turning the engine by hand. Do you know if there's a chance it's not blown up if it's a tooth off? Being that it's just misfiring a little bit? As I said there was a tapping in the distributer cover, but it wasn't audible from the heads. I unfortunately sent it to a mechanics as weather has dropped below 0°F, but I'd like to still come up with ideas lol.
I did some more research and I believe your vehicle has an interference engine, so having the timing correct is absolutely crucial. If the timing was off to a degree that the valves hit the pistons, the engine would be damaged. It sounds like you will have to rely on the mechanic now.
Very recently, I had misfires and ignition codes (P0301 & P0351) after I installed new spark plugs. Quickly, in the less than a day, I had CEL flashing (bad, bad, bad). It turned out aht the wiring harness to the ignition coils was defective. Once it was replaced, the codes (and the flashing CEL) went away.
So, to my mind, and my recent experience, this might be an electrical issue from substandard Chinesium or even OES parts. (In all cases, "New is not the same as known good"). Or it could be installation issues. All that has to be rechecked, and the quality of replacement parts needs to be verified.
Thank you so much. The wiring harness to the coils made a cracking sound when I moved them away. They were so old and brittle! Lexus will have the car tomorrow and I'll give them ideas to hopefully work off of in my situation. Thanks again!
Clearly, the timing is way off and the belt was not properly installed.
Did you watch the video? Although I'm happy you replied, I'd love an explanation if possible. The cam lines lined up with the belt, the crank lines were good too, after the two spins I swear it couldn't get more perfectly lined up. Was there something you saw in the video that made you think the timing is the culprit? Or was it the symptoms? I'm trying to learn so thank you for for bearing with me
https://youtu.be/cLJPTU2bP4U Here is a video of the start-up after the timing belt replacement. The issue seemed to get worse after taking it around the block and that's when it tripped codes. If you were driving around with bent valves, again would there be clatter? I truly never have had bent valves so I don't know. Thanks again!
Update: Lexus did a diagnosis because I didn't have time and said one of my plug wires were crossed! Trac and CEL are off now and it runs as smooth as butter! Long live the LS400 and thank you for the replies!