Something weird started last week. Monday I was backing out of a parking stall and it shut off completely. Sometimes I have delayed ignition issues no one's been able to figure out so i thought maybe it started weird (i literally just turned it on and started to back out). So i turned it off then cranked up again and it was fine, drove home 45 minutes. The next day...15 minutes into my commute i pull up to a red light and as I'm about to go again at low speed, shuts off. I mean the entire car shuts off, not just losing acceleration power. When this happens the entire dash comes on (AT oil temp light, oil light, CEL, etc). Turn it off then crank it up again...then the car's shuddering and vibrating so i'm thinking there's a misfire. Turned it off and called the tow truck. Takes it to a shop and i explain everything. the next day i get a call that everything's fine, no codes thrown (which i already knew so duh) but they drove it for a bit and nothing stalled. I couldn't get it until today due to work but they said they put 17 miles on it and it didn't happen so there was nothing to do.
After the first phone call I suggested TBI and MAF since I know my fuel filter and ignition coils were all replaced when i did a full top end rebuild around 175k (currently 208k). I have a scangauge wired into my car 24/7 so i'm always aware of new codes and fluids, etc. Today driving home from the shop voltage was ranging 13.7-13.9. TPS was fluctuating appropriately with acceleration, not sure what else i'd look at.
I was very disappointed with the shop (I do all my own work other than special tooling and that guy i trust is always booked out several weeks) but i didn't end up ripping him a new one because they didn't charge me anything so i partially forgive them.
I'm about to change clothes and get out there to look at the TBI and MAF. Anything else pop into your mind?

My mind goes to electrical failure, ignition failure, maybe A/F ratio? My cat converter rattles like a son of a gun which really only started two weeks ago. I know metals can get loose in there and make noise so it didn't alarm me.

I wonder if the Torque Convertor was stuck locked.

What will happen if it's it. When you stop at a stop sign, the engine will just die. Just like a manual if you don't push the clutch in.

Very good thoughts on the maf or throttle body, but mostly those throw codes.



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just took a look at a few things:

MAF tested fine for ohms
Sprayed it down anyways
TBI wasn't that dirty, sprayed it down anyways.
Throttle position sensor was out of spec registering .7-.88 ohms (FSM syas 1.2-3.2)
Accelerator pedal sensor was OK
Throttle control module was OK on terminals 3/4 but way high on terminals 1/2 (clutch resistance)
EFI relay was OK
Scangauge shows throttle position sensor at 13-14 at idle, and went up to 17 at 2500 rpm

not related to the shuddering but i also hear the familiar grinding at 2300 rpm...which makes me think that's the transmission since that's around the gears 1/2 shift range right? No other tranny issues and fluids been changed routinely. But i hear it and think "shit"


i should also mention my voltmeter/ammeter is weird lately. it doesn't measure volts well at all. AC in an outlet, DC, there's just drift in the numbers. Continuity and resistance seems to work ok, but idk since voltage doesn't. so maybe these numbers can't be trusted

wouldn't a solenoid malfunction throw the code p0740?

also if the Torque converter was stuck in one position that shouldn't shut the whole car off right? the engine shut down, radio, etc everything.

The shuttering is making me think it's the Torque Convertor..

The solenoid would give you errors.

The torque converter is all mechanical, so there are no codes to throw..

May not be. Just a thought.

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how would i test it? There's never been any slipping into gears.

also i'm thinking the rattling is a heat shield somewhere but i need an assistant to help me gas it while i'm under the vehicle.

Alternate Search for T4R - 3rd Gen Section


See if that will help you find the test procedure. Its in a FSM but almost everything 3rd gen related can be found with just this simple search.. :-) Almost 95% plus things are covered in this forum..Just finding it is the key.

Nothing has been wrong since I did those tests and cleaned the MAF. I don't think it was truly the MAF. Also on the torque converter note...why would it just be fine right after a rest period and not as reproducible?

I have the FSM and there is a torque converter clutch plate runout test but that's the only one i saw and that of course requires dropping it out which I'm not gonna be able to do.

I just watched a video on you tube by care care nut that throughly explains the Torque Convertor.

Most likely your TC was very hot when this occurred.

THIS Is the Most Underrated Car Invention in 2023 | The Torque Converter - YouTube

Explains how the lockout clutch works. How does the shutter occurs etc.

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That shutter i think is the TC now that i think of it. I've been messing with the gas pedal at different RPMs and the grinding/rattling noise is consistent with acceleration under load. Different inclines, different speeds, nothing at all coasting. must be it.

i'm gonna try a drain and fill this weekend and next weekend again with shudder fix.

i do downshift on declines to save my brakes. i wonder if that has been causing undue strain on the clutch lockup like in the video. very informative video

Shuttering is bad. My guess is your TC got just warn enough to start to warp.

When you drop your pan. Replace your screen filter as well. That will get more fluid volume throughout the transmission. Thus dropping heat levels.

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good idea on the screen. I have a B&M cooler on there and a magnefine filter and temps never crawl much higher than 165 driving in town and on freeways, often lower bc of the extra cooler. Mountain roads of course get up there but never above 210. So this wasn't overheated at the time because my scangauge didn't show anything weird.

Folks like to add extra coolers which doesn't hurt anything. Be good idea if hauling. However, they ran the 3rd gens all over the world with just the radiator cooler.

So if the rads changed every 10 years to prevent the milkshake. I personally don't see the need.
This is just me, though. Gets alot hotter in Africa and the Australia bush than here.

I also use a feel pro transmission pan gasket, so it's very easy to take off and replace the screen filter and clean pan magnets.

No a bad idea on inline magnetic filter. I just prefer the basics.

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did a drain & fill today with a tube of shudderfix. 5.5 qts came out (B&M cooler so extra) but one big SNAFU....I snapped a transmission pan bolt. I was tightening it down per the toyota FSM at 65 ft-lbs.....which is wrong. I checked my Haynes manual, HAYNES!, and it says 60 in-lb. Then I see Timmy mentions it on his video too that toyota has a typo. I'm furious. I did this service before but that was like 50k ago and I didn't have the FSM back then. I was using Haynes and youtube. So now I'm afraid to re-do this in a few thousand miles when i inevitably do drain and fill #2. It's a corner bolt too. Right now I have the Beck Arnley kit on there because I don't want to chip away FIPG again, but I'll do toyota FIPG at the 3rd and final fill.

Also found a loose heat shield at the 02 sensor like i suspected so I bolted that up. So who knows if the rattling was the tranny or the heat shield. Magnets showed what I expected for 50k service (my next date was at 212k miles and right now i'm just shy of 209k so it's about right).

What do i do about this bolt? Part of me thinks just fill over it with FIPG once I'm ready for the third fill.