Intermitent High Rpms
Thread Starter
|
New User
Joined: Sep 2003
Posts: 4
Likes: 0
Intermitent High Rpms
I HAVE A 92 F150 5.0 THE RPMS WILL RISE WHEN SHIFTING GEARS. PUSH IN CLUTCH AND RPMS WILL RISE FROM 500 TO A 1000 RPMS THEN ROLL OFF IF I LEAVE CLUTCH IN OR GO TO NEUTRAL. IT ALSO WILL STAY AT HIGH RPMS ON START UPS. HIT THE GAS IT WILL ROLL OFF, HOWEVER THE PROBLEM WILL SOMETIMES GO AWAY AND THE TRUCK RUNS FINE. CAN ANYBODY HELP ME ON THIS? PLEASE !!!!
Senior User
Joined: Jun 2003
Posts: 352
Likes: 1
From: Tillamook, Ore
I don't know if we have the same thing going on but my 90 f250 rpm's raise when I pull my auto into gear. Mostly when it's not warmed up, not so noticable after it's warm. Steve83 said it was probably normal because my tranny is computer controlled with the engine. But tell you what, I need to pay attention and keep on the brake when it does this cause it'll rev pretty good when it's cold.
Thread Starter
|
New User
Joined: Sep 2003
Posts: 4
Likes: 0
Mine will happen at any given time not just when it's cold. One other thing I should mention is that I noticed a slight sticking in the accelerator. I don't know if the problem is related or not. If so I am inclined to think possibly the throttle body is the problem. I just want a solution to the maddness!
Senior User
Joined: Jan 2003
Posts: 383
Likes: 1
From: Newport News USA
I wonder if maybe your TB is a bit dirty behind the butterflies which is also where the IAC sits. This would explain both the occasional sticking throttle, as well as the jumpy idle. If your Idle Air Control valve is a bit dirty, it may be hanging up and not working properly. But you might also check your Throttle Position Sensor. Grab a Haynes and check it with a multi-meter per their instructions.
Luke
Luke
Thread Starter
|
New User
Joined: Sep 2003
Posts: 4
Likes: 0
I pulled the TB off and cleaned it best I could. I did notice that if I pushed down on the butterfly valves that I could reproduce the same sticking feeling manually. I lubed the linkage real well and sprayed the TB down good with carb cleaner. I think I replaced the TPS and the Map. is the IAC the same as the map sensor? I will try performing the test per haynes manual though. we'll see what happens.
