‘94 LC with 251k miles, not triple locked. Been having an issue with it reving up and down and then stalling out when idling after running it for some time. Doesn’t do it from a cold start. Pic of the lights that come on after it stalls is below, any ideas??
Rough Idle / stall out issue
- Thread starter cruiserfan5
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You need to put more effort into researching this issue. There are countless threads on this subject. How long have you had the truck and what maintenance has been done?
Suggest you start by looking for vacuum leaks.
Suggest you start by looking for vacuum leaks.
- Thread starter
- #3
I bought it two months ago, previous owner didn’t report having this issue. Brought it to a Toyota shop and had an inspection done after I bought it. Didn’t stall while it was in the shop, until I drove it home so it seems to do it after driving for some time. Doesn’t do this from a cold start. Throttle and transmission cable were adjusted by the shop, they said the vacuum tubes looked fine. Otherwise it’s been a solid rig, but this issue is getting worse.
Torn intake plenum?
Does it sound like it’s sucking air?
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I have similar or the same problem as you. When cold everything looks good RPM starts higher depending on temperature and gradually coming down to 625.
But when I rev it and let of throttle it falls to 200-400 going UP and Down , sometimes staling right away and sometimes goes back to 625 after little while. I think I hear something like air sucking @DIRTBIKEUSA , It looks like its going from upper area somewhere around IACV area.
I changed some vacum lines which looked dated , clean MAF , checked air intake hose for leaks , changed spark plugs ( they looked all good - maybe one was smelling after fuel more than others , wasn't dripping wet but smell was different)
None of above helped with problem.
But when I rev it and let of throttle it falls to 200-400 going UP and Down , sometimes staling right away and sometimes goes back to 625 after little while. I think I hear something like air sucking @DIRTBIKEUSA , It looks like its going from upper area somewhere around IACV area.
I changed some vacum lines which looked dated , clean MAF , checked air intake hose for leaks , changed spark plugs ( they looked all good - maybe one was smelling after fuel more than others , wasn't dripping wet but smell was different)
None of above helped with problem.
Have you tied a compression test? That’s the very first thing to do to baseline the health of the engine..do one and post up the results. Get an engine stethoscope and check your injectors for the clicking noise they should all sound the same. The rear injector is hard to see..
Also have you verified that the ignition timing is correct and the spark plug wires are going to the right cylinder? Do you have a cross fire going on? Number and post up the spark plugs.
Get a flashlight and really look over the engine, maybe you missed something obvious..
- Thread starter
- #9
Still having the issue but I think I've narrowed it down. I replaced the intake hose which was old and cracking. Previous owner removed the cat (not a problem where I live), O2 sensors are put directly into the straight pipes where the cat was. I unplugged each of the O2 sensors at a time, and let the engine get hot and drove around, check engine light came on, but no stalling. I could not get it to rev up and down or stall with one of the O2 sensors unplugged. Bought two replacement Denso O2 sensors, installed them, it made no difference, the same problem happens when both are plugged in. With one of them unplugged, no issue. With both unplugged, no issue. Both plugged in, it will show the issue after heating up to operating temps. Haven't gone any further troubleshooting, wondering if no cat is throwing off the reading the from the O2 sensor.
If you play with the MAF do not unscrew the screws on the plug. Remove using clip.
- Thread starter
- #11
I actually watched a video watching a dude who did just that and removed it correctly. Although the clip was very old and stiff so a little of the plastic chipped off.