kaspotz

I recently purchased a 1993 es300 and am running into some issues with the engine stalling. First noticed it last week after driving on the highway, noticed the car feel like it was "stuttering." Luckily my apartment is right of the freeway exit so I made it there, but as soon as I slowed down the stuttering increasing. RPMs dropped, shifted it into park, then it died. Waited for a minute then started it back up to pull into my parking spot and it was fine, no shaking and I let it idle once parked and there was no issue.

I took it into a shop the next day and they said they couldn't find any issue with it. Said, because it's a 1993, there's no computer they can just plug it into to figure out what is wrong. This same shop changed the oil for me about two weeks ago and did a full inspection. They mentioned that the fuel injecting system could use a cleaning, but that it wasn't a dire need.

So I drove it to work and back all this past week and it was fine. Then, I'm driving home yesterday and it starts shaking again. At the first red light I had to stop at RPMs dropped and it died. Started up and got it home, albeit while taking it slow and having the same "stuttering" the whole time.

Does anyone have an idea what could be happening? If it makes any difference, I live in Phoenix and the car was parked in the hot sun all day prior to driving yesterday. But, the first time it acted up, it was nighttime and the car was cool, so I don't believe heat is an issue (radiator is working fine as well).

DRACO A5OG

Hmm?

Stuttering? Do you mean mis-firing like not all cylinders are not firing?

Next time this happens try to take a video if safe enough to do so.

Mis-fire could be worn plugs or clogged fuel system i.e. fuel fitler or fuel pressure regulator issue

DRACO A5OG

BTW, you have this diagnostic port, wrench should have known this:

kaspotz

Yeah I might try to get a video later, going to wait for it to cool down outside a bit. Could possibly be a mis-fire, I'm just not sure. It's just hard to describe...acceleration isn't smooth at all. As soon as I put the gas down you can feel something shaking.

Definitely will not take it back to that mechanic. They ran it through a car wash with the antennae up. Replaced it...but still.

DRACO A5OG

Keep us posted.

Maybe a video of the engine bay while idling???

kaspotz

So I took it out for a drive tonight and it was doing fine, went to the store and parked. Got in the car and on the way back it started stuttering at the first stop light I hit. One thing I noticed and didn't mention before, the RPM gauge starts dropping and rising fairly rapidly between 0 and 1k when this happens.

Red light turned green and I started video taping the dash to try and catch it in action. Pulled down the first side street and put it in park because I was hoping to get a video under the hood before it died. But when I parked, it was fine. Just stayed idling at 1k. Drove it around a parking lot a bit but no issues. Decided to drive home and didn't notice anything.

Think I'm going to take it to the local Lexus dealership tomorrow. Hoping they'll have a better idea than the last mechanic.

amlarajr01

Yes what other person said is correct. You do have a diagnostic port on the vehicle. Most reputable shops have the ability to read and pull codes. The problem comes in when you go to a smaller shop. The port on your vehicle is not obd2 like newer vehicles. It's an older system that cost more money for shops to have the right equipment available to pull those codes.
My first question to you in diagnosing the problem with out pulling codes would be to ask you if you have noticed lost in gas mileage or over all power when driving. If you have then it would suggest and ignition relayed issue. Like a failing coil possibly. A failing coil will work fine when cold then once warm will stop working. If you haven't had no loss in gas milage or power then I would suspect possibly a failing fuel pump. Usually when going bad they work fine when cold but once warm they shut off.
Like I said without diagnostic codes I can only give you a rough starting point. A best guess based on years of engine building experience and common problems with your year of vehicle.
If you have any questions feel free to respond and ask. Always glad to help