I’ve been trying to correct a slight misfire on my 97 LX450. Lots of parts replaced. Can’t find any problems visibly with harness- not even by EGR pipe. Corrected all vacuum leaks. Replaced crank position sensor. Full tune-up with plugs, wires, cap, PCV valve. I have an ARB bull bar on the front. If the truck is idling I can feel a faint “burble” in the bumper. It’s almost like a bass guitar playing some erratic notes. Aside from this, truck seems to run great. I’m wondering if anyone else on here with a tuned-up 1FZ and bull bar bumper is willing to check this out on their rig with it idling and let me know if they feel the same thing.
1FZJ Vibration / Miss Question (1 Viewer)
- Thread starter Indiana80
- Start date
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What you're feeling may be normal for an engine with miles. Have you checked timing?
Mine has a miss at idle that you feel through the body. Very irregular.
Mine started after a service.
I haven't found the cause yet.
Mine started after a service.
I haven't found the cause yet.
Same with me, slight change in RPM at idle, barely noticeable, changing plugs wires cap and rotor did not change anything. I wonder if it is a clogged injector?
- Thread starter
- #5
4000 miles on new short block. Rebuilt head. Idle is consistent between 640 and 670RPMs. Injectors overhauled by Witchhunter. I haven’t hooked up timing light yet but my ultragauge shows timing advance at 4 to 5 degrees at the idle RPMs shown above. One Cruiser guru told me the 1FZ is just always a bit “missy” at idle. I’ve improved my idle but can still feel the slight miss. I’ll check timing next.
My 1997 has had a lumpy idle. I recently set the timing to 6-7 btdc as shown in many threads on mud. Noticeable difference in idle quality and low rpm power...but it has 228k.
Tachycardic
SILVER Star
Got the same issue here. Started recently on a '94 with 280k on it. Engine rebuilt at 265k, charcoal cannister (VC120), PCV (Wit's End kit), and throttle cable (OEM) all change at 277k. Initially noticed the misfire at idle at 278k. The misfire became more noticeable after a 500 mile trip to Death Valley. I'm seeing 600-650 RPMs with minor blips higher during the misfire. Happens about once every 5 seconds. Only other mechanical issue I have is that I'm losing coolant at an alarming rate and see coolant sprayed and pooled inside the engine bay (hoping it's just hoses that need to be replaced). Otherwise the LC runs great, no overheating, CEL, etc. I'm wondering if I have a vacuum leak, or maybe an injector problem. The truck is in the garage to have some other work done, but they said they'd check it out. I'll report back about what they say.
- Thread starter
- #8
Some misfires seem to be normal at idle / lower RPM with low load. I’ve replaced tons of parts. My wiring looks good. I’ve replaced all vacuum lines except brake booster vacuum, but that hose looks really good. One of the biggest vacuum leaks I think I had was oil dipstick. I replaced mine with a new one- big difference in idle. The new dipstick seals so tightly that it’s a bit difficult to remove. The old one apparently wasn’t sealing. Same with my oil fill cap. It wasn’t quite sealing completely, either. Get all the little vacuum leaks fixed first, then reevaluate.
How's the valve adjustment?
- Thread starter
- #10
Not sure. I’ve adjusted valves before, but never on 1FZE. FSM makes it look like more of a job than I’m equipped for- requiring special tools and shims from Toyota. I plan to have an old Toyota tech look at valve adjustment for me.
- Thread starter
- #11
Also, the machine shop that rebuilt the head and used a new OEM Toyota valve grind kit should’ve adjusted them properly.
You should just need a set of feeler gauges to check. If it's all good you won't have to adjust anything.
Sometimes it shows up on a compression or leak down test too
- Thread starter
- #13
Gotcha. I did do compression test and I have 175-180 across all 6 cylinders.
