MuGGzyx

I have removed and cleaned the MAF with "MAF Cleaner" at this point and replaced my plugs and cables last year, but not caps and rotors.

When driving at average in town speeds (30-40) and around 2k RPM, if I try to accelerate the car feels like it is "stuttering". The entire car gets a little jerky and acts like it doesn't want to accelerate.
If I put my foot into it to accelerate faster it will down shift and take off as it should.

Also under load, like climbing a hill it will do it often and I will be forced to climb much slower than I used to.

Sometimes the idle is rough and the same "stuttering" seems to come when I sit at stops every 2-5 seconds.

FWIW it runs like a champ if I am at freeway speeds or accelerating hard, only seems to happen at a dead stop or when cruising in traffic..

I don't have a multimeter to test the MAF but some of the searches have made it sound like this could be the culprit. Ideas?

brad11140

iTrader: (3)

Could be. I dealt with the same thing and it turned out to be the fuel pump ecu. Do a search for definitive guide to hesitation issues. Test procedures there.

sc-driver

iTrader: (7)

Your not supposed to clean your maf sensor with that maf cleaner. Your car is a 92-95 which used karman vortex maf sensor type. Those cleaners are for hotwire sensors 96+

Have you been having the problems after you tried cleaning it? There have been a bunch of threads discussing this.

SW2UZ

iTrader: (3)

edit: ^ lol was texting and got beat to the punch

what type, hot wire (95+) or karmen vortex(92-94) if you used maf cleaner on the karmen vortex style it's prolly toast. (I may be off on the years for the different styles)

MuGGzyx

Um, it's the kind that has a solid triangular shaped shaft that goes down into the airflow channel, no exposed wires that I could see.

SW2UZ

iTrader: (3)

KV style, you may be able to salvage it, get some zero residue electrical cleaner and reclean the sensor after that let it dry overnight, there is a thread on the proper way to clean it and reset the ecu

edit: https://www.clublexus.com/forums/per...s-cleaner.html

https://www.clublexus.com/forums/2942667-post23.html

RSmotox

Im having an issue very similar to yours with my 1993 sc300. My problem is very intermittent. There isnt one particular time mine acts up. It can be right after start up in the morning, or even after driving the car for 20 minutes. I may be cruising 40mph, and it will act as if the engine is dying off bc no matter where I push the gas pedal at that moment the engine wont rev past 2000 rpms. once it is in this "mode", which can last two minutes or 20 minutes, i can have the gas pedal floored and the engine will rev up to 2000 rpms then die off to 700 rpms and back up to 2000 over and over again, but NEVER over 2000rpms........ the CRAZIEST thing then happens.......if i turn my hazzard flashers on, the "up and down" rpm surging goes faster then before and at the same speed as the blinking of the hazzard lights. PLEASE HELP! I just joined the Lexus group when i bought this car last week and dont know these cars well enough to know where to check first

1WILLY1

iTrader: (9)

im just throwing this out there but u may want to check your coils as well, i had a similar issue turned out one of the coils was not proper.

RSmotox

the 93 has a distributer. maybe the main coil that feeds the distributor? Im just wondering why it does it only sometimes and not all the time. I figured it had to be something like a loose connection somewhere?

1JZPWRD

iTrader: (59)

I would first go by a voltage reader from walmart. Check the maf, the coil packs, the iacv, and the set the tps sensor. These are all symptoms of what you are describing. Also check the fuel ecu! Lastly listen to the exhaust and see if one side sounds different than the other. Just a thought.

ZPEED

u need to replaces the fuel pump ECU. or modify it.

RSmotox

thanks guys. i really appreciate the help. I have a great place to start looking, and I must say the people in this forum are 1000 times more helpful then the last forum I was a part of when I had my twin turbo 300zx. So thanks again.

zuma1597

iTrader: (1)

i have the same problem with my sc300. i just bought the car and i don't know the previous owner did to it. please post if you fixed it and will post if i fix it.
Thank you for your time
- Esteban

MuGGzyx

Thanks for the advice so far. I just borrowed a multimeter from a buddy and need to figure out how to use it but I am getting there.
I checked the coils, they look to be in perfect condition. I pulled the AFM (MAF?) and used some canned air (the stuff for PCs) and tried to blow out the two tiny holes on it.

The only time I can 100% re create the symptoms is if I am going about 30-40 and start to climb a hill, it will get really bad then but otherwise it seems pretty random. I am just kind of bummed that these stupid sensors seem to be super expensive.

MuGGzyx

Hmm, well as per another thread on here, I unplugged the AFM altogether and went on a drive, same exact symptoms. So I am thinking that it is not the AFM...

I tried looking at the "definative hesitation" thread and honestly I am not too sure what I am looking at on most of that stuff.