I have a 93 Land Cruiser, and I noticed that the engine light comes on the first start-up of day when I start to accelerate, but if I shut the engine off and turn it back on immediately then the engine light goes away even when while accelerating. Has anyone else experienced this?
Engine light goes away on the second start up?
- Thread starter LandCruiserGEO
- Start date
This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.
You're going to need to pull codes.
My guess is some sensor is getting tired and not providing the correct feedback voltage when cold, but when warmed up its happy.
The only way to know which one is to pull the code.
My front CAT heater circuit pulls this stunt. Likes to be packed in mud, when clean it throws a code....tried half a dozen times to fix it, and gave up.
My guess is some sensor is getting tired and not providing the correct feedback voltage when cold, but when warmed up its happy.
The only way to know which one is to pull the code.
My front CAT heater circuit pulls this stunt. Likes to be packed in mud, when clean it throws a code....tried half a dozen times to fix it, and gave up.
- Thread starter
- #3
Come to find out - It was a bad knock sensor I bought at the auto store. I put the old oem knock sensor back and engine started running good again. No engine light.
My '93 does the exact same thing!
Initial startup then once you hit ~2k rpm light comes on, but after ~10 minutes of warming up and then a restart the light doesn't come back. I know it gives code 52 and I know my front knock sensor is one of the cheap eBay "OEM" models so I finally broke down and bought a real OEM one.
Your story has convince me to brave the Texas heat and get it swapped over to the legit one to see if it goes away.
Malleus
Far west of Siegen
The prices for the OEM parts are criminal
alia176
SILVER Star
Agreed. I bought two knock sensors for my daughter's 5VZ-FE from Amayama for a significant cost savings. I also ordered bunch of stuff or a head gasket job at the same time.
alia176
SILVER Star
I'm curious if you fixed the problem by replacing the knock sensor or my moving the wire around, which might've temporarily improved the connection! Let's hope it's the former, not the latter! In my case, both knock sensor wires were brittle so I ran two new parallel wires from the sensors to the ECU pins. That finally cured my issues.
Two years ago, I replaced the whole harness and now everything is MOBETTA!!!
I ordered mine from Partsouq and I'm hopeful now it'll fix the issue.
Ali, where is that ECU? IN case my legit knock sensor doesn't resolve the issue I may go the same route and run new lines.
- Thread starter
- #9
I eventually need to replace my harness as well lol. And yes it was the former sensor. I actually changed both knock sensors and I didn’t have issues with the new sensor in front of the engine, just the new knock sensor on the rear of the engine.
Finally found the time and better temperatures to do the knock sensor swap in the garage.
I ordered a 27mm deep socket to ensure I would have something able to hold a grip on it, as opposed to some adjustable wrench, and deep enough to not damage the plug are.
I swapped the front knock sensor (ordered as an "OE" from eBay) with the more expensive OE from Partsouq.
While I was doing the swap I had the EFI fuse pulled to clear out any ghost errors and so far have not seen the engine light come back on when driving!
I'll top off the tank and watch to see if there's any improvement as I know the engine light kicked in a safe mode to make it run richer.
Hope to have good news in future but wanted to come back to this post as we all have done our research in this repository and found help/solutions from decades before us.
Love our community!
alia176
SILVER Star
right behind the glovebox!!!
Thanks, luckily the new knock sensor resolved the issue
Bad news, gents!
Had longer drive for the commute this morning and maybe the ECU finally realized it'd been reset.
Check engine light came back on as bright as ever.
The usual shut off and restart made it go away but I was really hoping the actual OE knock sensor would have remedied it.
I think you need to go back to Post #2 and as @Rusty Marlin suggests, pull the codes. Everything else is guesswork and that s*** gets expensive real quick.
Still same code I mention in post #4, error code 52 which links to front knock sensor as the easiest; after that starts getting harder to chase as it could be loose ground, loose connection of wire, faulty wire, or ultimately ECU fault.
Must have missed that. My bad.
