I know this is probably one of many threads most of us on here have a headache trying to answer all the while trying to figure it out. I've done my research and tried to minimize the the cause(s) of these issues. After finding that many threads like these were left unanswered and really a bust, I thought I'd bring the question to those who see the same level as I do. Problem: After a Friday night of unmentioned festivities, the truck started acting up on the way home. It's as if the torque/power was thrown out the window and all that was left, was horsepower/top-end; in other words, I could barely pick up speed to go with the flow of traffic at 60mph. The motor has a mean vibration when picking up the idle, could it be the harmonic balancer? A collapsed exhaust? Bad O2? At first, I thought the flapper inside the AFM was stuck open, as this has happened twice since I've owned the Toy, but it wasn't. Second, I checked for any vacuum leaks and did a compression test. All Good! Third, the oil is fine and no milky coolant inside the radiator. Fourth, I checked the valve train and checked for any loose rockers or excessive play. All is well. I brought it to a friend who was supposedly the Toyota Master, but unfortunately, he only knows carburetors and not EFI - No Pun intended brother, but you can't be dubbed the Toyota Master if you don't know at least the EFI side of the infamous 22R. I'm about ready to send this to the Toyota/Lexus Specialist himself who rebuilt my ECU & AFM, but before I go spending dollars on something that I could fix, I'd like to see what you all have to say. The motor only has after-market bolt ons Headers/Intake/Spark plug wires. Need the expertise from my fellow Mini Toys World-Wide!
Does it happen immediately after startup, or does it start having issues after driving for a bit? If it doesn't do it immediately on startup I would suspect the O2.
Physical vibration or a running vibration? I'm guessing you have some crap in the fuel filter or bad injector connection. It could also be ignition related such as a bad spark plug or wire too.
Not understanding your vibration question. If you mean does it shake, yeah it does, like bad motor mounts or somethin. I've got new LCE wires new cap and rotor new NGk plugs. There's no hesitation, like its tryin to run, it runs just no bottom end power, it's as if the calipers were so bad you can't barely even go anywhere.
A physical vibration will cause your mirrors to shake like when you have a wheel way out of balance. A running vibration is like a miss so the power isn't there because it's sputtering etc.
I would check the timing & don't forget to use the jumper wire to disable the advance! Also check the compression!
Physical vibration. You could see the hood shaking once it's in the stand, also when I was test driving it, the trans was just vibrating too.
Changed the O2 sensor and still not giving power. Running out of options. Forgot to mention that the exhaust has been spitting out black soot as well.
Doesn't matter how old they are, only how they read. If they are equally dark then you have a general overfueling issue (FPR failure, ect.) if one is dark then you have a cylinder issue (stuck open injector, ect.). FWIW your description of the vibration is leading me to suspect the latter.
FWIW? I'll check them tomorrow, I remember when changing them out, noticed that one was darker than the other. @white trash - I'll look into that as well. Thanks guys.
For what it's worth. Your truck has a knock sensor? Toyota's diagrams show it was 4wd-only, and I have never seen one on a 2wd truck.
You would think they would, but I went through several years of parts diagrams for third-gen trucks with the Toyota dealership counterman and according to Toyota no 2wd 4cyl truck ever had a knock sensor. I have also never seen one in the wild, but I have seen quite a few that, like my current truck, have obviously never had one screwed into the block.
im pretty sure the pre-91 trucks had knock sensors. my truck (94) didnt have one. and neither did the ECU from a 91. i have other older ECU's (3 yellow connector) for efi - they will all run but the CEL will come on due to the missing KNK sensor. if blowing out black stuff from the ex, could be running rich or no good spark. so it responds good at WOT? - if yes, could be a stuck open or leaking injector. usually, a bad spark plug/wire/cap would feel more like a power cut -if it was really bad. sounds like ur issue "clears up at higher speeds" im leaning towards a fuel issue as well (fuel pressure reg, just pinch the line umbee!!!! lol)