T.p.s

[gero1]

i have had a throttle positioning sensor go out twice in my boat. the last time it was down to 58% and when thry put in the new one it would only go to 89%. near the end of last summer my rpm's were down around 4600 at wot but the boat will still run around 77 with 3 people and a half tank of fuel. if it is the sensor again, what would be causeing it to go out so much? and why when a new one is installed will it only go to 89%

[mrfixxall]

The t.p.s. varies in voltage at idle any where from .50 to .99 volts..somtimes all it takes is a little tweek,loosen the screws and twist it a little and the % will go down.. if its inder 1 volt at idle then i wouldnt worry about it....if their burning out then check the suplied voltage wire and make sure it isnt over 5 volts if it is then you may have a bad resister in the ecm causing too much voltage to go through the tps and making it burn out...always check it with the engine off...then check it with the engine running and see if theirs a voltage differance because your your alternator may be putting out to much voltage and spiking the ecm..the alternatoe can even put out a/c voltage when it going out and throw off the readings..the percent readings should be 0% at idle and 99% at wot..the tps may be mis adjusted or the idle is to high if its not at 0 % at idle...if you dont see 99% your throttle may not be opening all the way..

hope this was helpful and good luck.

[gero1]

positively the best answer to a question i have ever asked!!! thank you. but...if the boat ran 81.7 on gps 2 days after they replaced the t.p.s at 89% what will happen if it opens up all the way to 99%???????????

[mrfixxall]

positively the best answer to a question i have ever asked!!! thank you. but...if the boat ran 81.7 on gps 2 days after they replaced the t.p.s at 89% what will happen if it opens up all the way to 99%???????????

It would probably run the same..try disconnecting the throttle and with the engine off and ignition on with the scanner hooked up and by hand give it wot and check your readings..if it still reads 89% loosen the screws in the tps and try to turn it so it reads more%..if you cant get it to 99% you can oval out the holes in the tps to get it to 99% but that will also affect the idle % as well and you may have to turn the idle down so it reads 0% at idle.
good luck.