Ranger throttle surge
Ranger throttle surge
Got a 1992 2.3. When i barely press the gass it acts as if it wants to stall but when i let out on the clutch taking off it picks back up as the rpm’s rise. It could be idling and if i barely press the gas it slightly hesitant then picks up. What could this be?? Fuel pressis good no vaccume leaks and good compression
Welcome to the forum
Fuel injected engines have no Jets to add fuel when throttle is opened, and they have no Vacuum advance to change spark timing when throttle is opened, if either does work well engine will stumble
These are computer controlled mostly using the TPS(throttle position sensor)
Its a 3 wire sensor on the throttle plate shaft, opposite side of throttle linkage(cable)
Its a variable resistor like a Volume Control or Light dimmer
Like all sensors it uses 5volts in from computer, then sends computer a lower voltage based on position
.69v to .99v when throttle is closed(just under 1volt)
4.5v to 4.7v when throttle is Wide Open(WOT)
The top wire is 5v in
Bottom wire is Ground
Center wire is the control voltage, the one you can test
Key on engine OFF
Test center wire, you can use a sewing needle to pierce any wire without damaging it, to test its voltage while its still hooked up
See if there is a stumble in voltage as you open throttle, TPS should have smooth stable voltage from closed to WOT
Heads up
If PCV Valve has not been changed in a few years then change it, or clean it, if these get sticky inside from oil build up they can cause symptom described
Not an expensive part and should be changed or cleaned, every 3 oil changes
Fuel injected engines have no Jets to add fuel when throttle is opened, and they have no Vacuum advance to change spark timing when throttle is opened, if either does work well engine will stumble
These are computer controlled mostly using the TPS(throttle position sensor)
Its a 3 wire sensor on the throttle plate shaft, opposite side of throttle linkage(cable)
Its a variable resistor like a Volume Control or Light dimmer
Like all sensors it uses 5volts in from computer, then sends computer a lower voltage based on position
.69v to .99v when throttle is closed(just under 1volt)
4.5v to 4.7v when throttle is Wide Open(WOT)
The top wire is 5v in
Bottom wire is Ground
Center wire is the control voltage, the one you can test
Key on engine OFF
Test center wire, you can use a sewing needle to pierce any wire without damaging it, to test its voltage while its still hooked up
See if there is a stumble in voltage as you open throttle, TPS should have smooth stable voltage from closed to WOT
Heads up
If PCV Valve has not been changed in a few years then change it, or clean it, if these get sticky inside from oil build up they can cause symptom described
Not an expensive part and should be changed or cleaned, every 3 oil changes
Thread
Thread Starter
Forum
Replies
Last Post
JASONGR81
General Technical & Electrical
17
Feb 7, 2021 10:22 AM



