I just bought an SC400 and just realized that it has no power at all. Could this be the TPS? The dealer told me the car uses 2 of these. How do you test to see which one is bad? All info will be greatly appreciated.

 

engine question, engine forum. Moved

Likely your cause. I test mine with a snap on scanner.

 

Sorry about that O.L.T. I made a mistake posting in there. When you say you use a scanner to test yours, what do you mean? How do you test it? Do you know exactly where they are located on the '95 SC400?

 

I am only aware of one Throttle Position Sensor...It just plugs in...Clean the leads and try that...I dought that is the problem...No power means you could have restricted exhaust or an electrical problem of some kind.. Where does the car experience no power....If it is only happening from a dead start that is the stock torque converter and that is normal...Slow takeoffs in the SC4's

 

Gotta intervene here Jibby, the TPS judges the position of the gas pedal and on my scanner you can watch the pedal steps (0-5) as you depress the pedal. This is the TPS telling the scanner (and the car) where the throttle is.

When one goes bad, you only get like a step 2 at best. and the remaining 3 steps of the throttle are never achieved. Even if the throttle opens via the gas pedal, the MAF and O2's are still at minimum flow, as well as the injectors.

 

Torque converter? That does not sound right to me Jibby. I had the same problem with my old 2000 Maxima and to solve that problem, I changed the tps and all the power came back. O.L.T is probably right and I will go and get the (2) TPS sensors. Is there any possibility that a blocked up converter could cause such a severe loss of power? The car does not even sound like an SC400, it sounds like a dead 4 cylinder car.

 

I did own a car dealership for several years and have maintained and repaired these cars over and over again....Pretty much have seen it all...I experienced these types of problems many times on over 50 Sc400 and Ls400 and the TPS was never the problem...Dirty throttle body caused a bouncing or irratic idle...Loss of power clogged cats, or an electrical problem..Just my two cents....

At stock these cars have a very weak stall rate torque converter that makes these cars very slow at take off...Designed for old folk.....That is fact.

 

I found the problem and fixed it. One of my coils were dead. I replaced it and the car runs as a true SC400 V8 should. Thanks Jibby and all the guys that responded to this thread in attempt to help me find the problem.

 

Slightly off topic, but is it just me that instantly thinks of Office Space when reading anything about the throttle position sensor (TPS)?

 

TPS reports!! LMAO!! I love that movie!

 

Ummm, my SC400 has two throttle position sensors. Actually one is a 'throttle position sensor' and the other (right next to it) is called the 'sub throttle position sensor'. My SC has Traction Control and from what I've read they are the ones that have TWO of these sensors. But, I've never owned a dealership....