When the truck is rolling with clutch in the truck will idle rough and sometimes dies.
While driving if you push in the clutch the truck will idle rough with the RPMs jumping from 500 to 1000 and sometimes the truck will die. while sitting still with the clutch in the truck idles rough but not as bad as when its rolling or coming to a stop. Now twice the last few weeks it wont start at all. The truck turns over and doesn't sound weak but it won't fire. After waiting about 15 minutes it will finally start.
My car has 130000 miles.
My car has a manual transmission.
Experienced mechanics share their insights in answering this question :
This is a common symptom of the idle air control valve failing. This unit monitors the air intake as it is mixed with fuel prior to entering the motor. When this fails, this will cause a rough idle at low RPM’s. I would recommend having an expert from YourMechanic come to your home to diagnose the rough idle firsthand for an accurate repair.
How to Identify and Fix Common car Problems ?
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The most common reasons a Chevrolet Colorado engine stalling are the fuel system, the air intake system, or the ignition system. Search our network of RepairPal Certified shops near you to speak with a technician about your issue.
There are three major causes for a stalled engine: A lack of fuel, a lack of air flow and improper ignition. Running out of fuel is one of the most common causes of engine stalling, but dirty fuel injectors or a plugged fuel filter can also be the culprit. Your engine needs air to run properly as well.
Some of the most common sensors that lead to engine stalling include the mass airflow sensor (MAF), engine coolant temperature sensor (ECT) and manifold absolute pressure sesnsor (MAP). The idle air control valve (IAC) and exhaust gas recirculation valve (EGR) are also well known for causing engine stalling.
If you have a newer model car, the reason may be a malfunctioning electronic sensor or an imbalance in the air/fuel mixture. However, for older model cars, it could be the idle speed control actuator, a faulty alternator, or even a dead battery.
Engine stalling
If the idle control valve fails completely, it may leave the vehicle without a source of air to maintain a proper idle. This may result in the engine stalling while operating, and in some cases may result in an engine that will not idle at all, and stalls as soon as it is started.
An idle air control valve, also called an idle air sensor control motor, is an electrically operated valve that controls the amount of air that bypasses the throttle plate in cars with a fuel injection system [source: Autozone]. This causes the idling speed of the engine to change as needed.
Another symptom commonly associated with a problematic crankshaft position sensor is intermittent stalling. If the crankshaft position sensor or its wiring have any issues, it can cause the crankshaft signal to be cut off while the engine is running, which can cause the engine to stall.
When your engine shuts off when you slow the car down its often as a result of a: Malfunctioning transmission. Low fuel pressure, dirty or defective fuel injectors, or broken fuel pump. Bad oxygen sensor or mass flow sensor.
Shaking or vibrating may be caused by many different things such as faulty spark plugs, poor fuel pressure or misfires. Other things such as a faulty idle air control valve may cause the engine idle to drop below the normal idling RPM which may also cause the motor to shake or vibrate more than normal.
Your vehicle could have dirty fuel injectors, a damaged fuel pump, a blocked catalytic converter, a faulty mass airflow sensor, broken spark plugs, or even an accumulation of moisture.
A rough idling engine can be caused by spark plugs or spark plug wires. Spark plugs use the electrical current received from ignition coils to ignite the air/fuel mixture within the combustion chamber. A plug that is damaged or installed incorrectly can result in fuel being burned at an inconsistent rate.
incorrect idle speed: an iac valve that sticks in the closed position will create an idle speed that`s too low. your rpms will drop way down the car may feel like it`s about to stall. on the other hand, an iac valve that sticks in the open position will create an idle speed that`s too high.
A rough idling engine can be caused by spark plugs or spark plug wires. Spark plugs use the electrical current received from ignition coils to ignite the air/fuel mixture within the combustion chamber. A plug that is damaged or installed incorrectly can result in fuel being burned at an inconsistent rate.
It may have been damaged by overheating or by dirty automatic transmission fluid. They can also be damaged if the engine`s computers fail and attempt to engage the transmission at too low or too high an RPM level. This RPM level is known as the engine`s “stall speed” and can be tested by any certified mechanic.
Relevant Questions and Answers :
the most relevant questions and answers related to your specific issue
When the truck is rolling with clutch in the truck will idle rough and sometimes dies.
ANSWER : This is a common symptom of the idle air control valve failing. This unit monitors the air intake as it is mixed with fuel prior to entering the motor. When this fails, this will cause a rough idle at low RPM’s. I would recommend having an expert from YourMechanic come to your home to diagnose the rough idle firsthand for an accurate repair.
I changed the fuel pump and truck ran great for 3 days. Now after 3 days, the truck dies. It will start running for a few minutes, then dies like before.
ANSWER : Hi there, thanks for writing in. I’d be happy to help. It sounds like you should disconnect the connector to the fuel pump and inspect it for any signs of getting hot. The female connections may be too loose on the fuel pump and lose contact after running and getting hot. If there are indeed any signs of problems, then I’d suggest replacing connector and adding dielectric lube to pins before installation. This should solve the problem, but if you continue to experience issues, feel free to reach out to us for help again.
The truck intermittently, has a very rough idle, and runs rough,usually after warming up.
ANSWER : Hello. This can be caused by a number of different things. If this occurred right after you had gotten fuel then I would start by testing the fuel pressure. I would do this when the vehicle starts running poorly. It is possible that the bad fuel contaminated the fuel pump and it is not putting out the right pressure. If the fuel pressure is fine then I would check the other sensors readings with a scan tool. One other common thing that I have seen on this engine is a leaking intake manifold gasket. It starts leaking on the bottom side and that leak causes the MAF and MAP to not read correctly which causes it to run like this. If you would like to have this rough running condition looked at, consider having a YourMechanic certified techniciancan come to your home or office to diagnose why it is running rough.
I changed fuel pump and truck ran great for 3 days. Now after 3 days truck dies. It will start runs few min then dies like before
ANSWER : Check the bottom of the fuel tank for sediment. Age and mileage could have accumulated a lot of it at the bottom of the tank. If you did not, check and change the fuel filter. Rule of thumb – replace the fuel filter any time you replace a fuel pump. Also, check the wiring for any chaffing on the fuel pump when you remove it. While your problem is kind of unique, I have seen many GM truck fuel tank baffle loosen over time, occasionally rubbing against the fuel pump can intermittently short it out and/or block the fuel pump pick up. To have this diagnosed, consider having a certified expert from YourMechanic inspect the stalling issue to have this corrected.
My truck died while driving. Now will start, but dies when I push brake. If I start in neutral, I can put in drive and go but dies – 2003 Ford F250
ANSWER : Hello – your symptoms suggest that once your cold start features are no longer needed – engine warming up – there is an air "leak" that ruins low speed running. Causes could be a leaking exhaust gas recirculation (EGR) valve, or leak in the air intake. A failing fuel pump relay (burned contacts) could cause similar behavior, contacts become hot, then won’t pass enough current to run the pump. Failing pump can also act this way – gets hot and fails. I recommend a starts, then dies inspection performed by a mobile, professional mechanic, such as one from YourMechanic, who will come to your location, diagnose this problem, and give you an accurate assessment of damage and cost estimate for repairs.
Rough idle when electrical is used
ANSWER : Hi there. As electrical components and accessories are used, more draw and strain is placed on the motor to power the alternator. As such, existing small idle problems will be accelerated when the engine is asked to give more. In most cases, a rough engine idle is caused by a vacuum leak, dirty fuel injectors, EGR valve, mass air flow sensor or problems with the idle control valve. It would probably be best to have a professional mobile mechanics complete a rough idle inspection at your location to pinpoint the source of your problem.
Rough idle, possible misfire, bad oxygen sensor a possible cause
ANSWER : There are a number of things that can cause a misfire to be present, but a failing oxygen sensor is certainly one of them. As you know the oxygen sensor reads the exhaust gases and relays this information to the computer which then makes adjustments to the fueling of the motor. When this is not working properly, this may cause inaccurate readings to be sent to the computer resulting in improper fueling adjustments to be made. This will no doubt cause an erratic idle and in some cases cause a misfire depending on the adjustment made. I would recommend having a professional from YourMechanic come to your location to diagnose and inspect your truck.
High Idle, stalls when a/c or defrost is turned on and dies completely after some rough idling. If turned back off car is fine.
ANSWER : Hi there. The fact you able to get the idle speed to drop by tapping the gas pedal, lead me to believe the high idle is due to a sticking accelerator cable. Another possibility could be, a faulty throttle body not allowing the throttle to return to the closed position. Proper diagnoses should be performed to avoid unnecessary repairs. I recommend having your vehicles high idle be diagnosed and repaired by a certified technician, such as one from YourMechanic.
