throttle positioning sensor

[Braomi]

my 98 suburban would not start this morning and hard starting for thelast 4 days in the cold morning . I left it for about 4 hours and tried again and it fired up but ran at 5000 rpms i shut it off and disconected the cruise cable and then tried again it started fine and ran normal but as i step on the gas it loses power , i called a mechanic and he suggested the throttle positioning sensor does this sound right before i go spend money on a new one.... thanks

[j cAT]

Originally Posted by Braomi

my 98 suburban would not start this morning and hard starting for thelast 4 days in the cold morning . I left it for about 4 hours and tried again and it fired up but ran at 5000 rpms i shut it off and disconected the cruise cable and then tried again it started fine and ran normal but as i step on the gas it loses power , i called a mechanic and he suggested the throttle positioning sensor does this sound right before i go spend money on a new one.... thanks

find a mechanic that will measure the resistance of TPS when the throttle is varied if it jumps TPS is defective if it smoothly changes resistance from idle to wot you must look at other areas. TPS is good. also i find it hard to believe that with the throttle body plates closed engine could get to 5,000rpm. was gas pedal in wot mode because of floor matt? loosing power when looking to accelerate is a lean condition. possible TBS but could be fuel and many other pcm engine controls....fuel pump/pressure/relay/filter/volume of fuel pumped,this is a common area of this type of complaint......

[Braomi]

just came back from talking with mechanic and he says its not the tps and there was no floor mat in the truck and nothing to get stuck on . That had the mechanic very confused also with no light on (engine light)the dash he said its not electrical but somthing mechanical it starts and runs now but if i step on it going down the road it wont pickup and go?

[j cAT]

Originally Posted by Braomi

just came back from talking with mechanic and he says its not the tps and there was no floor mat in the truck and nothing to get stuck on . That had the mechanic very confused also with no light on (engine light)the dash he said its not electrical but somthing mechanical it starts and runs now but if i step on it going down the road it wont pickup and go?

it is possible that the cat's/exhaust is resticted this will cause your problem so check engine back pressure as this will show if there is a resticted exhaust the o2 hole is used to measure back pressure. and also fuel pressure .......