93 Sc300 Bogging Down Hot Or Cold

[maner]

I have a 93 sc300 with 90,000 miles. Just recently it began to run rough, bogging down at random speeds as if it wasn't getting any gas. But this problem is intermittent. It doesn't matter if the engine is hot or cold. Took it in and they said it was the mass air flow sensor. So I got it replaced, 2 days later same problem. Then they said the fuel pump is "losing pressure" . I Called lexus dealerships and was told that the fuel pump either works or doesn't. Im lost. If this problem sounds at all familiar please help. Its my only car and I can't afford to keep replacing parts that aren't correcting the problem. Thanks for any info.

[jzz30]

the fuel pump either works or it doesnt but there is a fuel pump computer that might be giving you problems. there is a connector where you can jump and run the pump constant. maybe someone can chime it because i dont know which pins to jump because i dont have my manual in the country im in now...

[jpkRE]

Hey Maner, I am having the same problem with my 92 SC300, the dealer wants me to replace the MAF sensor too and he said that "this is the first step" and it will cost me close to a grand! THEN he said if that doesnt work we need to replace the ECU which is closer to 2K!

How did you solve your problem? what happened? I could use some advice because i dont have any cash to spend on the dealer throwing parts at my car.

Thanks!

I have a 93 sc300 with 90,000 miles. Just recently it began to run rough, bogging down at random speeds as if it wasn't getting any gas. But this problem is intermittent. It doesn't matter if the engine is hot or cold. Took it in and they said it was the mass air flow sensor. So I got it replaced, 2 days later same problem. Then they said the fuel pump is "losing pressure" . I Called lexus dealerships and was told that the fuel pump either works or doesn't. Im lost. If this problem sounds at all familiar please help. Its my only car and I can't afford to keep replacing parts that aren't correcting the problem. Thanks for any info.

[don_juan_miami]

i know this might sound dumb, but try checking your crankshaft pulley. Mine was slipping and it seemed like all of a sudden the car would stutter. I would be driving and then st- st- stutter... id look like an idiot. Then turning down the street one day i heard a little "clang", lost my power steering, my battery light came on (usually means the alternator isnt functioning) and the car was making the most awful "screeeech" ive ever heard. Turns out the crankshaft pulley on our cars is comprised of (to put it simply) a big ring fit inside another larger ring with rubber and glue holding them together. Hard to explain but in my situation, hard driving ate away at the "rubber" and the larger ring came off, throwing the belt off, at the same time, busting up my radiator fan assembly, and knocking around in my engine bay. The only good side to this? I went ahead and changed the pulleys on the car with unorthodox underdrive pulleys, got a little bump in HP and a smoother running engine. Also check your serpentine belt tensioner... those also tend to get faulty with age.

Happy Hunting.