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Q: help. i have a 94 Lexus sc400-RPM goes real high until it shifts on 1994 Lexus SC400

just recently cut off the cavt. converter and replaced it with a straight pipe and also replaced the radiator. The car continues to do the same thing.... RPM goes up real high before shifting and once it hits about 60mph it runs okay....The shop i took it to could not find the problem. I was going to replace the transmission filter and gaskets, spark plugs, and coil packs but unsure if i should if that is not the problem. has this happened to someone else.
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Hi Roy,
Gil, the SC400 has two distributors at the front of each cylinder head with a separate coil to operate each distributor, it does not use a coil pack. If one coil fails the engine typically will run but run poorly. I'd look at coolant level, coolant temp switch have seen the idle control at the throttle housing fail on some of theses. Roy is right needs cat. convertor on car. There is a company that independent auto repair shops get their information from, this same information is available inexpensively for people that work on their own cars.. The information is year make and model specific, covering repair procedures, torque specifications, fluid capacities and specifications, service bulletins, component locations, wiring diagrams ect.... Alldata is very easy to navigate
There is a professional service called Identafix. They only deal with professional repair shops. They are in the Minnesota 651-633-8007 begin_of_the_skype_highlighting 651-633-8007 end_of_the_skype_highlighting. Your auto repair shop do all their diagnosis tests, and discuss your problem with a team of professional technicians great service cheap and very bright people. If the repair shop that are repairing your car are stumped this is a great service. This company only deal with automotive repair shops and don't answer questions for the general public but are an amazing knowledge base.
first of all, put the cat back on.
you need a trans shop to see if there is any adjustment for the throttle pressure in the trans. if not, then it is internal and most likely will have to be overhauled.

if it was the transmission .... wouldn't it still have power but just wouldn't shift right?
depends on whether it is slipping. it sounds like it is by the high rpm until it shifts.

Thanks Roy... I guess i take it to The Car Doctor so i can pin point what the problem is exactly rather than guessing and buying parts that i may not need. appreciate your time. Gil
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