What does a GMC Sierra 1500 idle like?

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. 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.

What kind of idle does a truck have?

Rough idle but otherwise… Truck runs great when driving down the road and idles smooth for a couple minutes after coming to a stop. Then it develops a “stumble” that is very pronounced. I’m fairly confident it isn’t ignition as the distributor, cap, plugs, wires, and coil are new.

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.

What should the idle rate be on a 1997 GMC Truck?

Underdog, I don’t know the 1997 5.7, but 1000rpm sounds like a high idle, not where it should “bottom out”. A V8 should idle at 500rpm. GoNDown, did you recently disconnect your battery? After I left mine dead in the yard for a while and didn’t charge it, when I started it up it ran like you describe for a few days and then it was 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.

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 truck idle when its cold?

When youre truck is just warming up, its still cold the efi is dumping fuel because its in like “Choke” mode. As it warms up, it leans the fuel air mix out to acomodate warm engine condition driving. So, when its idleing cold its got the fuel to compensate for the extra air leaking in.

What causes poor idle and stalling on a Silverado?

Carbon & varnish build up will cause poor idle. If after a cleanup you still have the problem have a tech check with a scanner. Engine hot in “D” IAC counts should be 15-30. Beyond the cleaning above, check for an air leak from either a vacuum hose off or a loose clamp, etc. between the airfilter box and the throttlebody.

Why is my GMC Sierra 1500 stalling out?

No change. Next, read somewhere that bad ground wire on Thermostat housing can cause ECM issues. Checked it, cleaned it off, verfied that contact wanhers are all steel and attract a magnet, reinstall the ground wire.

Is there an idle air control on a Silverado?

Your truck doesn’t have an Idle Air Control since it has an electronically controlled, drive-by-wire throttle. One can get MAF cleaner at the auto parts store. Spray the tiny filament wires inside the MAF with the cleaner.

Why does my GMC Sierra 1500 run rough at idle?

The spray smoothing out the rough rpm is an indication of the engine running lean, could be low fuel pressure, could be a vacuum leak. With it running rough at an idle and smoothing out at a higher rpm is a general sign of a vacuum leak.

Why does my GMC Sierra 1500 stall while in gear?

Motor wants to stall while in gear (but doesn’t do it out of gear once over 1000 rpm it dosent) seem to stall and it is only from a dead stop. Fuel filter has been replaced and TBI was rebuilt last April but it sort of used to do something like this when it was like 40 degrees or below. Could be torque converter lockup solenoid in the trans.

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 Chevy Silverado to stall at low speeds?

You might have a bad IAC valve. (idle air control valve) The PCM retracts the pintle in the valve constantly to maintain desired rpm idle, and rpm at low speeds. Its a 4 wire valve bolted on to the throttle body. If its a mechanical problem with the spring or pintle in the valve, it will not set a code for the IAC. If you decide to replace it.

What causes white smoke from exhaust when idle?

What Causes White Smoke From Exhaust When Idle? If you have white smoke from exhaust when stopping or idling, your combustion chambers engine might get oil inside, which cause them to burn off the exhaust. This will cause white smoke, along with the idle issue.

Why does my car idle at high idle?

If this tube becomes loose or broken it can leak un-metered air into the engine effectively causing an unbalance (via the mass air flow MAF sensor) in the computer system which can produce fast or slow idle.

What does it mean when you have smoke coming from your engine?

Billowing fumes almost always mean there’s something seriously wrong with your car. But the color of that smoke might help you understand what type of repair can help fix it. Many engine problems create abnormal or excessive exhaust smoke. In your engine, fuel is burned in each cylinder, creating exhaust gases.

What does white smoke mean on a Duramax engine?

White smoke from an LB7 Duramax engine often indicates faulty injectors. We’ve heard of rollin’ coal, but rollin’ snow? Not a good sign. Blowing white smoke is a red flag for your diesel engine, yet we see this happen all the time to our customers.

Can a Duramax be used in a GMC Sierra 1500?

For instance, we can control the engine block and the engine head separately to maximize the effectiveness of the cooling system,” Barta explains.

Is the GMC Sierra 1500 going to be new?

2021 could mean a new truck new you, but that’s not the case for the 2021 GMC Sierra 1500. The GMC Sierra has hardly any changes for the new model year, meaning it still has the same disappointments from 2020. What’s new for the 2021 GMC Sierra 1500?

What kind of engine does GMC Sierra have?

The maxim towing capacity for the 2,7-liter four-cylinder engine has also been increased by 2,300 lb to 9,200 lb. With the GMC Sierra AT4 trim, you’ll gain a new off-road high clearance step and new Goodyear Wrangler Territory all-terrain tires. 1. The 2021 GMC Sierra 1500 has the same old interior.

Which is the best engine for a GMC Sierra 1500?

When it comes to outstanding fuel efficiency that doesn’t compromise on capability, the new Duramax ® 3.0L Turbo-Diesel I-6 engine for the 2020 GMC Sierra 1500 is a seriously smart powertrain.

Are there any problems with the GMC Sierra 1500?

302-horsepower 4.8L V8 4-speed automatic 4WD w/low range service traction control light was coming on. The vehicle wouldn’t go over 35 mph. Battery disconnect reset the problem temporarily It was actually a problem with the throttle body. Found out later it was a recall. Replaced coil and plug wire for Cylinder 6.

For instance, we can control the engine block and the engine head separately to maximize the effectiveness of the cooling system,” Barta explains.

How long does it take a GMC Sierra to get to 60 mph?

When the truck isn’t taxed with a trailer, the Duramax whisks the Sierra to 60 [mph] in around 8 seconds according to informal iPhone testing. And unlike some turbo-diesels, this one has almost no turbo lag. But the coolest thing about this engine is the super-wide torque band.

Are there any changes to the GMC Sierra 1500?

New distributor comes with new ESC electronic unit, pickup coil, cap & rotor, also. No change. Next, read somewhere that the fuel pressure regulator diaphram if split could cause flooding. rebuilt throttle body unit, rebushed it and boiled it out and added rebuild kit and brand new Borg Warner injectors.

What should fuel pressure be in a GMC Sierra 1500?

I assume there really is no way of testing the the regulator itself considering it’s incorporation. 38 people found this helpful. The test is: 12-15 psi when the key is turned on and the pump will shut off within 3-5 seconds and the fuel pressure should drop to 12-13 psi. 11 being the bare minimum and 13 the Max.

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 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.

Which is the latest generation GMC Sierra truck?

GMC has always made top-level engineering the rule, and the latest-generation Sierra is no exception. Watch the video to see the best of what Sierra has to offer in action. 1.

Which is better GMC Sierra or Chevy Silverado?

The 2020 GMC Sierra 1500 is comparable to the 2020 Chevrolet Silverado 1500. Both half-ton pickup trucks receive similar reviews and performance ratings, but the Sierra has a better overall look and feel to it. The new trailer-tow mirrors and camera system help make hauling up to 12,200 pounds a breeze.

What does rough idle mean on a GMC Sierra?

rough idle, stalling, loss of power. o2 sensor code 44 (lean) Replaced: coolant temp sensor, tps, map sensor, fuel filter, and o2 sensor. It will run normal on occasion but only lasts about 45 seconds or so.

What kind of engine does a 1985 GMC Sierra have?

This 1985 Serra 1500 4×4 has been recently restored and features an LS-swap. Power comes from a 5.3 1985 GMC High Sierra 1500 4×4 Shortbox finished in Indian Bronze paint. This was also repainted som 1986 GMC Sierra square body. New GM 350 crate motor, radiator, electric fan, edelbrock intake, fi-t …

Why does my Silverado Sierra have high idle?

Cleaned the throttle body and went to put it back on and start it with out the intake attached to the throttle body. It idled funny so I shut it off.

Why is the idle speed of my car so high?

Step 2 – The idle air control motor (valve) is responsible for controlling the engine idle speed, if this part fails or becomes weak the engine idle speed could become erratic, additionally, this condition may or may not trigger the MIL (check engine, service engine soon light.)

Is there an intake manifold leak at high idle?

You may have an intake manifold leak on the bottom side of the engine at the lifter galley (I base this assumption by the fact that when you spray eather into the valve cover it changes the engine speed.) Re: high idle PLEASE HELP!!! You probably have a leak like aste25 mentioned.

What kind of help truck has HIGH idle?

SilveradoSierra.com • Help truck has high idle!!! : Vortec 5300 5.3L V8 Help truck has high idle!!! Cleaned the throttle body and went to put it back on and start it with out the intake attached to the throttle body.

What is the TBI code on a 1990 Chevy truck?

Consult a service manual or see below for any check engine light code definitions. You can use a late 80’s or early 90’s GM TBI definition. If you have access to a scan tool use a hook up for a 1990 350 cu. in. 5.7L Chevrolet truck. For some scan tools enter VIN 10th“L” 3rd“C” 8th“K”.

What causes idle surges on a car ECM?

Idle surging can be caused due to other issues in the car, but if it happens in conjunction with other throttle position sensor symptoms, the culprit is often the TPS. At idle, the ECM will not get the correct information and the throttle will variate randomly causing idle surges.

How to troubleshoot your TBI fuel injection system?

Troubleshooting your TBI Fuel Injection System Most of the problems encountered while installing your fuel injection system or after a time of operation are very simple. If your check engine light is on you more than likely have a hard fault meaning something is grounded out, unplugged, operating out of range or has gone bad. See

What makes a’91 TBI 350 surging at idle?

It basically almost dies out, and then surges back to life (probably a little higher than normal idle), then repeats continuously until you apply some throttle. If I had to guess, I’d say it’s a dirty throttle body, or possibly injecters. If it is one of these, what would be the best way to clean them?

Why does my TBI 350 have zero power?

This weekend I put a new idle air control valve and o2 sensor in, and the symptoms still persist. Along with the erratic idle, the engine has absolutely zero power. It stumbles as if it’s missing a couple of cylinders when you accelerate.

Why does my GMC Sierra 1500 not start?

If the flow/pressure increased when the truck started that means that you are sucking fluid from the pan therefore the pump is working. That means that the problem is most likely in the valve body. When it warms up there is a 1/4″ npt tap on the drivers side that you can tie a cheap gauge into to see you line pressure.

Why is my radiator so loud in my truck?

Well, Alabama is now getting a constant 90 degree weather and with that I’ve started noticing a VERY loud noise around the radiator area (I know nothing about radiator/ac fans). My truck is an ’09 1500 (5.3) and the noise seems to be happening more often when I use the remote start.

How old is the 1995 GMC 1500 truck?

I got the truck from my 89 yr old father in-law at 96,000 miles. It’s got dents but no highway miles. All farm use. It runs great and has never had any issues.

Why does my GMC Sierra stall at 30 mph?

Never threw a service engine light or a code and would readily re start. 2 weeks ago it quit at 30 mph, wouldn’t restart and SES lit up. Code indicated crank positioning sensor. Had it replaced and so far so good. If yours behaves as mine did it could be a while before you get a traceable code. I own a 1998 GM Sierra 5.7L 2wd automatic.

What was the problem with my GMC Sierra?

August 2007, Brought truck into dealership and they figured it was a weak fuel pump and was replaced, September 2007 stalling of engine continued. NOV. 2007 dealership replaced ignition harness, and stalling continued. Dec. 2007 I replaced the battery and did a thourough cleaning of the battery terminals.

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.

What causes stalling on a 1990 Chevy k1500?

So far it has a new distributor (for an unrelated problem), idle valve, throttle position sensor, knock sensor, temperature sensor, fuel filter, plugs & wires. The idle valve and tpi both tested bad, and replacing them helped on general driveability but didn’t affect the stalling.

Why does my Chevy Silverado stall at low idle?

I have the same problem with the stalling at a stop and low idle. It idles at around 400rpm when warm. It runs fine when cold. When I go from 15 mph to a stop it will stall about 50% of the time. The other times it will recover after the tach drops to almost “0”. I have a 2001 Sierra 1500 with the 5.3 V8.

How to help me with a Chevy k1500 misfire?

× Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!

Is it hard to start a Vortec rough idle?

On any start after the initial cold start in the morning, it is hard starting. You have to feather the gas a little and it shudders but it will start then you have to give it a little gas or it’ll stall. Driving, its fine as long as you are moving.

What’s the idle RPM on a 99 Vortec?

Truck recently had an exhaust manifold replaced. When its cold (as in first thing in the morning), it fires right up and high-idles for a few seconds and runs fine. After the first few seconds, its idles rough. The engine struggles to keep it above 7-800 RPM.

What’s the idle RPM on my Chevy Suburban?

My 1997 Chevy Suburban (5.7) is acting up on me. When I start it up the RPM and idle seem fine. As I let it sit for a couple of seconds the RPM’s slowly begin to drop until they finally bottom out at about 1K. As soon as I put it into Reverse/Drive etc. the RPM’s drop below that mark and it struggles to stay running.

What should coolant temp be when engine is hot?

With a good OBD2 code reader, you can also check the live data and the parameters of the CTS sensor. Check that the temperature value of the CTS is around 80-90c when the engine is hot. A lot of engine coolant temperature sensors have two wires and the sensor is controlled by Ohm.

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