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The engine laps indicator rises madly and disproportionately
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The engine laps indicator rises madly and disproportionately
The engine laps increases madly and is not proportional to the actual engine rolls and this happens at the beginning of the ignition and may recur even after starting the engine in the work Please help and how to fix the problem
I am kind of leaning towards thinking it is because of the throttle position sensor (TPS). Do you know how to test the TPS? Testing it in Ohms the readings should correlate near exactly with throttle inputs throughout the range. I would check that.
Does it kind of stay at an increased RPM while nearer to idle, and return normal after beginning to accelerate? Checking all vacuum lines would be worthwhile for what you have going on. Something with them leaking could cause high RPM, especially nearer to idle.
Spark plugs and fuel injectors would be another suspect, but less likely.
Yes. The TPS connects to the throttle plate on the throttle body. The position sensor has a variable resistance potentiometer (or contact points, depending on model) that sends a varying voltage signal to the Power Control Module (PCM, your car's engine computer) according to the position of the throttle plate.
This plate rotates when you depress the gas pedal to allow more air to enter the intake manifold. With the engine running, the position of the throttle plate (along with other sensors) tells the computer how much fuel the engine needs at any given moment.
So, without the correct signal coming from the TPS, you begin to notice drivability problems. Fortunately, it's not that hard to test the sensor.
The most typical failure you'll find on a TPS is wear, a short or an open on the circuit of the contacts or variable resistor. This guide will help you test the throttle position sensor in a few minutes and know whether you need to replace it.
Index
I. How to Test a Throttle Position Sensor
A. Is Your TPS Connected to Ground?
B. Is Your TPS Connected to Reference Voltage?
C. Is Your TPS Producing the Correct Signal Voltage?
I. How to Test a Throttle Position Sensor
The most common TPS test is to measure for resistance (ohms) or voltage at the various positions, including throttle plate closed, half open and fully open. We'll use voltage to test the TPS here.
1. Open the hood and remove the air cleaner assembly where it connects with the throttle body.
2. Inspect the throttle plate and the walls of the throttle body surrounding the throttle plate.
* If you see carbon buildup around the walls and under the throttle plate, spray some carburetor cleaner on a clean shop rag and wipe the buildup with it until the surface is completely clean. Carbon buildup can prevent the throttle plate from closing properly and moving freely.
3. Locate the TPS mounted on the side of the throttle body. The TPS is a small plastic block with a three wire connector.
A. Is Your TPS Connected to Ground?
1. Carefully unplug the electrical connector from the TPS.
2. Examine the electrical connector wires and terminals for dirt, contamination and damage.
3. Now, set your DMM to a suitable setting, like 20 Volts, on the DC voltage scale.
4. Turn the ignition key to the ON position, but don't start the engine.
5. Connect the red test lead from your DMM to the battery positive post, the one marked with a "+" sign.
6. And touch the black test lead from your DMM to each of the three electrical terminals of the TPS electrical connector.
* The one terminal that reads 12 Volts on your DMM is the ground terminal. Make a note of the color of this wire.
* If none of the terminals reads 12 Volts, there's a problem in that part of the wiring leading to the TPS you need to fix because the TPS has no ground.
7. Turn the ignition key OFF.
B. Is Your TPS Connected to Reference Voltage?
1. Now connect the black test lead from your DMM to the ground terminal on the TPS connector you just identified.
2. Turn the ignition key to the ON position, but don't start the engine.
3. Connect the red test lead to each of the other two terminals.
4. One of the terminals should read 5 volts, or pretty close to it. That terminal is providing the reference voltage to the TPS to produce the voltage signal. Make a note of the color of the wire connected to this terminal. The third wire corresponds to the signal voltage or signal wire.
* If you don't get 5 volts from any of the two terminals, there's a problem in the circuit you need to fix because there's no reference voltage going to the TPS. Check the circuit for bad terminals, loose, dirty or damage wires.
5. Turn the ignition key OFF.
6. Plug back in the electrical connector to the TPS.
C. Is Your TPS Producing the Correct Signal Voltage?
1. Now backprobe the signal and ground terminals on the TPS electrical connector. If necessary, use a couple of pins to backprobe the wires.
2. Connect the positive (red) test lead from your DMM to the signal wire and the black negative (black) test lead from your DMM to the ground wire.
3. Turn the ignition key ON but don't start the engine.
4. Make sure the throttle plate is fully closed.
5. Your DMM should read around 0.2 up to 1.5 Volts or close to it, depending on your particular model. If the readout on your meters shows only a zero, make sure you're at a low setting—usually at the 10 or 20 Volts setting. If your meter still reads zero, continue with this test anyway.
6. While watching the readout on your DMM, gradually open the throttle plate until is fully opened (or have an assistant gradually depress the gas pedal to the floor).
* Your DMM should read 5 volts or close to it when the throttle plate is fully opened.
* Also, make sure that the voltage increases smoothly as you gradually open the throttle plate.
* If you notice the voltage skipping or stuck at a certain voltage value, as you gradually open the throttle plate, your TPS is not working properly and you need to replace it.
* Also, if your TPS doesn't reach 5 volts, or close to it (up to 3.5V on some models), when the throttle plate is fully opened, replace the TPS.
7. Repeat step 6, only this time use the handle of a screwdriver to lightly tap on the position sensor as you open and close the throttle plate. If the voltage skips as you tap the sensor, replace it.
Note: TPS is directly involved with transmission shifting characteristics...
You are welcome. Have you been able to use a scan tool, or are you getting any codes? Codes do not always show up though.. It would be good to check for them either way.
It is staggering all of the possibilities that could cause deliverability issues. It is best to take a systematic approach to try and figure out an issue.
With yours, it sounds like it can be narrowed down based on some possible likely causes. There are three probable reasons that I know of that may cause the symptoms you describe. 1 - TPS... High Idle Speed: The TPS may report faulty values causing the engine idle speed to be increased above normal. This is normally found in conjunction with a slow engine return to idle speed symptom. 2 - The intake manifold having a leak, or another vacuum leak somewhere is also very highly probable. 3 - Idle Air Control valve (IAC) could be another very likely reason.
With the testing. You search out for and hopefully find the malfunctioning component. Otherwise, the testing can be used to rule out and eliminate the possible likely suspects. Which helps you to focus your efforts to look in other directions, for other possible reasons.
With testing the TPS sensor (and the wires and circuitry associated with it), maybe you find that to be the problem? If the TPS checks out okay, then you know to move forward investigating in other directions.. In my opinion, I believe the TPS is very probable. So, I go there with testing first.
I think having a vacuum or intake manifold leak to be a very highly probable reason as well. I would consider checking for vacuum and intake manifold leaks to be an extremely important thing for your symptoms. It is easy to check. Spraying carb cleaner all around the intake manifold and vacuum lines while the engine is on and running would signal you that there is a leak, and is a problem. The engine will change to speed up when spraying near the leak(s), if they are present.
Testing for intake manifold/vacuum leaks and the proper functioning of the TPS would be the highest priorities on my list of things to check. If those appeared okay then the next likely and relatively easy thing to check would be to look at the IAC...
There could be other things to look for if not finding problems with the above. It could be the vehicles computer malfunctioning, or a connection to the computer that is not proper, possibly an issue with something in the transmission, or another sensor somewhere? Hopefully, you begin by looking in the right direction... You can at least systematically verify what is working correctly as you go along, until you hopefully find the corrupt component(s).
As you start looking to figure out the issue, I will definitely continue to try and help you if I think I am able.
The Intake Air Temperature sensor (IAT) monitors the temperature of the air entering the engine. The engine computer (PCM) needs this information to estimate air density so it can balance air/fuel mixture. Colder air is more dense than hot air, so cold air requires more fuel to maintain the same air/fuel ratio.
Inspect the wiring and connectors between the Intake Air Temperature Sensor and the Powertrain Control Module to see if there is any obvious abnormal broken or frayed wires.
You can test the IAT in the same similar manner using a multimeter, like checking the other sensors, to help determine wether it is a problem.
(edited to add): If you go to testing the IAT sensor with a multimeter (it sounds like you should), then test the signals first... Go so far as holding the multimeter in-place, and verify that the readings on the multimeter do not fluctuate if/when you shake and move the wiring around too.
Yes, I checked the wires and they were all good. When I checked the temperature of the engine air, I found it as destructive as in the attached pictures. Then I noticed that the attachment sensor in the pictures was very hot.
I noticed that the attachment sensor in the second picture was very hot and when the test was given random readings...I have Disconnect it and will replace the two senses
The engine laps indicator rises madly and disproportionately
