OralePinkY

I have a 90 LS, recent water pump done a month ago aswell as plugs and wires a couple of weeks before that. About 2 weeks ago while driving, the car decided to start dumping fuel in and lost a lot of power.
-236k miles on the ODO
-It also now takes longer to achieve operating temp and longer to shift up.
-CEL is not on (bulb is definitely ok, light stayed on simultaneously with 'TCS off' light before the replacment of water pump and both shut off after the replacement, not sure why)
-Engine has shut off in the middle of a 3 point turn (going from reverse to D) and while stopped at a light. (that was today while driving to work, have since started it up and has NOT shut off while idling)
-MAF has been replaced with a used one, also unplugging eithier maf showed no differance, as well as cleaning them with MAF cleaner.
-Initially, when I first put it on a lift the Cat's were glowing red hot so I replaced them with pipes (I'm not exactly rolling in dough) thinking they were clogged.

After doing research on the knock sensor and crank sensor, both seem to have CEL on as a sympton, and don't exactly have the same symptons as mine.
I am not in financial position to keep throwing parts at it, so any info would be GREATLY appreciated.

sanstoette

I'd suggest finding a factory service manual, but Id look into the coolant temperature sensor.

timmy0tool

iTrader: (7)

from another thread. it seem it could be that your ECU capacitors are defective (common). check out the link in the quote below.

LScowboyLS

I like this answer! but yeah, ECU capacitors is also a strong possibility

LScowboyLS

these symptoms show the car was going into open loop operation, a strong indicator of a sick ECU, but certainly not the only possible cause.

OralePinkY

You guys are awesome!
I'll go pull the ecu and check the condition of the caps.
If it is the caps, would purchasing them from a electronics store be ok, or am I better off ordering them from Digikey?

Also called up autozone, they have a coolant temp sensor for 25$ w/ lifetime warranty, but I've heard of LS's having 3 temp sensors, how would I know its the one I'm looking for without pulling out the old one first?

sanstoette

The green sensor should be the one you want... the grey sensor next to it should be the one for your gauge cluster.

LScowboyLS

please use ONLY the capacitors linked to in my thread, your local electronic store does note have these very rare and hard to find low-ESR premium Japanese capacitors

I would purchase the real Toyota coolant temp sensor (green one in photo) - some people have had luck with the Autozone version, but this is way too important of a part to go cheap and save a lousy $25 for one of the most critical sensors in the entire car. - the Toyota p/n is 89422-20010

cobalt91

The early 400's MAF shouldn't be cleaned. This thing is pretty sensitive to cleaners. Are one or both of the cats getting hot? Might be a coil. Hard to tell with out codes. Good luck.