paulzlexus

Hello all,I am really hoping someone can help me with my sc400.I bought it for 1300 knowing it had a few problems,it had a broken crossmember,and needed a timing belt water pump job. I replaced the broken crossmember,drove it a week or 2 and started leaking oil from front crank seal.Did the timing belt-oil seals[cam and crank]and water pump,idler pulleys and belt tensioner.Drove it 3 or 4 thousand miles started getting warm here in az. so I took out radiator and back flushed with air and water[got out stop leak or headgasket repair crap]out of it.drove it another month or so and everything was great till last evening and it started reving up to 2100rpm and back down to about 1100rpm. I have the service manual on disc but cant find anything related to this problem.Also no CEL and not showing code?Can anyone point me in the right direction ---please.

SC400slide

iTrader: (11)

WHen I had fluctuations in RPM's these are what the issues were: Both main 02 sensors and the TPS.

paulzlexus

I found that if I pinch that 1/2inch hose going from air intake to IAC in front of intake that it idles fine WHY!!!!!!!!!! I am so frustrated

SC400slide

iTrader: (11)

Then that could mean you have a vacuum leak either on that line or someplace else. Too much air is causing your car to run bad...? I'd dig in the engine bay and follow every vacuum hose and look for any cracks or broken hoses.

paulzlexus

As of this point in time I been over every single vacuum line under the hood.Can the IAC control go bad?Is it sesitive to water because all this started after flushing radiator.