What kind of idle does a GMC Sierra have?
After the truck starts and is warm at a stable idle in park/neutral it’ll rev up fine. But the stable idle won’t last long, it’ll idle low and rough. Mpg has decreased drastically and give off a rich smell when running.
Is the warm engine undriveable when cold?
This time it started with an idle around 1500rpm, slowly dropped to 1k, then quickly cycled back up to 1500. It did this for a minute or two, then dropped down to the rough idle, which seems to run between 500-800, kind of hunting around. Is there a key sequence that is used to help it learn? The car is undriveable when warm.
How long does a warm engine idle for?
With a steady throttle, it fluctuated between 3 and 3.5 for a couple mins, then bogged out and stalled. Next time I started it, it went to 2k intially then started hunting between 1k and 1500, with about a two sec interval. After a couple mins, fluctuated around 750, but not steady.
What causes a GMC Sierra 1500 to stall?
But the stable idle won’t last long, it’ll idle low and rough. Mpg has decreased drastically and give off a rich smell when running. 308 people found this helpful. Bad hesitation off of the start, pumping the gas pedal helps to get her going. Pushing the pedal hard well bog it out and almost stall. 290 people found this helpful.
Why does my GMC Truck idle rough in the morning?
So the past couple months I’ve noticed my truck has a really rough idle in the mornings when it is cold out, to the point where it has even died before. I just replaced the plugs about 3 months back and it ran fine after, people have told me things like it is the o2 sensors to the cat is plugged up to my fuel filter is bad.
When did my GMC Sierra air conditioner stop working?
I had a 2001 GMC Sierra that did this when truck was less the one year old (summer of 2001 is when it was). The dealer had the truck in the shop idling for a long time and the A/C worked perfectly. I told them to take it for a ride and see. So the service manager in an effort to convince me nothing was wrong went for a ride with me driving.
What can I do about rough idle when warm?
If direct fuel injectors are the trouble-maker then, clean them using a blend of powerful solvents and high pressure. Another option to try includes fuel system additives, which clean fuel injectors. Note: An additive can sometimes, however, cause a rough idle problem.
Why does my car idle when it is warm?
When the cars idle gets rough, it hard to comprehend the related causes. It is because rough idle when warm can either be caused by one faulty component or through series of problems. Hence, after knowing the ways to troubleshoot rough idle when warm problem, anyone can now keep a check on their vehicle’s status.
What causes a Silverado Sierra to hesitate when accelerating?
As of today it starts fine and idle’s fine but when accelerating you can get up to speed by slightly pushing the pedal,but if you try to give it some gas anything above slightly pressing the pedal it hesitates and backfire once you push it to that point then it hesitates at any speed when trying to give it gas Just guessing here. 1. Spark Plugs?
What causes a GMC Sierra 1500 to lean?
The only other thing that will cause a lean condition is low fuel pressure. A vacuum leak will be problematic at idle and go away with higher rpms. Low fuel pressure will get much worse at higher rpms. 123 people found this helpful.
What causes a car to run at a rough idle?
A PCV valve leak can cause the air-fuel mixture to run too lean, and this will cause a rough idle. Proper periodic servicing of the PCV valve will prevent this situation from occurring.
Why is my 5.3 L missing and rough idle intermittently?
5.3 L Missing and Rough Idle Intermittently I have changed Spark Plugs,Wires ,Coil Packs, and removed Fuel Injectors and soaked overnight. Engine code is a P0304. Misfire Cylinder #4. Most of the time around town is alright. When i put it on highway, it will surge like its cutting off and then pick right back up and be fine. Fuel Presure is 55 psi.
Is the drivig engine smooth at low idle?
So smooth you could balance a coin on the engine even at low idle revs of around 650 rpm. In fact drivig with the TPS disconnected is quite acceptable, except that automatic gear change down does not happen (as expected). Have had the car for approx 13 years and has been a great, reliable family car.
What’s the RPM of a car when it idles?
When the car starts it idles fine at about 1000 RPM. As soon as it warms up, it starts to idle rough, between 500 and 750 RPM. It almost quits running. As soon as you give the car some gas it runs just fine.
Why is my Chevy Silverado running rough at idle?
Really, your Silverado will be running rougher at any RPM, but a misfire will be most pronounced at idle. Spark Plug Wires – While not every model and engine combination of vehicles today comes with spark plug wires (a lot are now coil on plug), if your Silverado happens to have them, they can go bad and cause a rough idle.
Is there an engine misfire code on a GM 4.8L?
Engine Misfire or Rough Engine Idle on GM 4.8L, 5.3L, 6.0L is becoming; more common and getting harder to diagnose. Because, GM V8 engines are very prone to a rough idle and engine misfire when cold. The check engine light may also come on, with codes P0300, P0171 and PO174.
How to troubleshoot a GM 4.8L 5.3L?
You can find this tutorial in Spanish here: Cómo Diagnosticar y Resolver Una Falla en Cilindro (GM 4.8L, 5.3L, 6.0L) (at: autotecnico-online.com ). The core symptom of a misfire is rough idle. This isn’t the only symptom that your GM van, pickup or SUV might experience… here are some more that you might see:
Why does my car idle all the time?
If the computerized engine control system is faulty, high idling can be one symptom. A vacuum leak in any of the hoses can be the culprit—inspect them all for leaks. A bad idle-speed control unit can cause the problem; it may need to be replaced.
What causes a GMC Sierra to idle roughly?
Here are the main components of the ignition system, as well as what would cause them to make your Sierra idle roughly. Spark Plugs – One of the absolute most common causes (if not the most common reason that your Sierra may be misfiring) is the spark plugs.
What causes a Chevy Colorado to rough idle?
When one or more of these variables is off it can lead to a rough idling condition. Most of the time the culprit is going to be the ignition system, although there are a myriad of other causes.
What causes an Audi A4 to idle rough?
A super lean running engine will often idle rough. The fuel injection systems job is to atomize the fuel into fine mist. If a fuel injector has an issue with this process, it will either let too much or too little fuel into the combustion chamber relative to the amount of air.
Why are my spark plugs not working on my GMC Sierra?
Spark Plugs – One of the absolute most common causes (if not the most common reason that your Sierra may be misfiring) is the spark plugs. Although most modern vehicles use iridium spark plugs, they still need to be changed at the manufacturers recommended interval.
What was the problem with my GMC Sierra 1500?
Did have one cracked vacume line from the throttle body to the purge solenoid, also replaced. Seems to have plenty of vacume through out the system. Removed and inspected the egr valve, no excessive carbon build up and appears to be working properly, good vacume going into the solenoid, replaced the solenoid just for good measure.
What happens when the diaphragm is ruptured on a GMC Sierra?
If the diaphragm has ruptured it will literally be like putting a hose with fuel into the intake and running it full. When it initially started to go it probably slowly flooded the engine to where it seemed to run ok but the excess fuel created a ton of carbon coating the O2 sensor. Since no air could pass through it, it gave a false lean reading.
What does the fuel smell like in a GMC Sierra 1500?
If so pull the air filter off and sniff the throttle body for a fuel smell. If the diaphragm has ruptured it will literally be like putting a hose with fuel into the intake and running it full.
Why does my GMC Sierra suddenly stop running?
Truck suddenly stops running, acting like it’s out of fuel. There is fuel in the gas tank and, I can hear the fuel pump when I turn the ignition on. Is there a fuse, or relay that is maybe causing this to happen?
After the truck starts and is warm at a stable idle in park/neutral it’ll rev up fine. But the stable idle won’t last long, it’ll idle low and rough. Mpg has decreased drastically and give off a rich smell when running.
If the diaphragm has ruptured it will literally be like putting a hose with fuel into the intake and running it full. When it initially started to go it probably slowly flooded the engine to where it seemed to run ok but the excess fuel created a ton of carbon coating the O2 sensor. Since no air could pass through it, it gave a false lean reading.
The only other thing that will cause a lean condition is low fuel pressure. A vacuum leak will be problematic at idle and go away with higher rpms. Low fuel pressure will get much worse at higher rpms. 123 people found this helpful.
Why does my GMC Sierra 1500 stall at high RPM?
At higher rpm seem almost like the exhaust is clogged but the cat has been bored, itll rev up but just wont really go. Today experienced a poping sound almost like a backfire from underneath. After the truck starts and is warm at a stable idle in park/neutral it’ll rev up fine.
What’s the problem with my GMC Sierra truck?
When I turn the key it cranks for about 1/4 second then nothing . None of the gauges or power locks and windows work . The battery is fine . Last night while driving all the gauges quit working and the a/c compressor kicked off , but the truck still ran fine .
At higher rpm seem almost like the exhaust is clogged but the cat has been bored, itll rev up but just wont really go. Today experienced a poping sound almost like a backfire from underneath. After the truck starts and is warm at a stable idle in park/neutral it’ll rev up fine.
Why does my GMC engine start but not run?
Repair guides and support for cars, trucks, and SUVs manufactured by GMC. Answered! View the answer I have this problem too Is this a good question? An engine will start but not run when the fuel runs out .
Why does my Chevy Truck start and idle?
Not sure why this test caused a better and longer gas flow than the above test of just putting the ignition in the ON position and seeing how much gas comes out of the line before the fuel filter. Last test says to start the vehicle and remove the relay.