Why are my GM 454 backfires breaking down?

If you see any white stains around the ground bracket, the coil is breaking down due to being over worked ( too long at max voltage). Another thing to check is fuel pressure. The system is already a low pressure system to start with. Unfortunately you have to tee into the pressure feed line to get this info.

Where are the spark plugs on a GM 454?

It is not an HEI like its predecessors, it has the ignition coil mounted off to the left on the intake manifold (changed that with a spare coil I had) no change there. The plug wires are the MSD street Fire 8mm ones and the spark plugs seem to be firing.

What causes a car engine to not start?

All engines require three things to start and run: spark, fuel and compression. If any one of these is missing, your engine will not start. But with all that working your engine will not start. Engine Will Not Start-The most likely cause is that the fuel injectors are probably not opening.

Where is the advance spring on a GM 454?

There is a mechanical advance spring set up under the distributor cap. Also, unless the engine system has been updated; there is a vacuum advance unit attached to the metal base under the cap. The top item is to replace ALL the vacuum lines.

What kind of Chevy truck won’t start?

In this video we encounter a condition where a 2002 Chevy Silverado ( Similar to GMC Sierra ) pickup has a symptom of the engine cranks over but won’t start…. In this video we encounter a condition where a 2002 Chevy Silverado ( Similar to GMC Sierra ) pickup has a symptom of the engine cranks over but won’t start….

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 .

What to do if your truck wont start?

To avoid throwing guesses and parts at your truck, have the truck scanned for trouble codes as a first step. Some of the auto parts suppliers offer free code reading like Pepboys, Nappa, Advanced auto parts,etc and some of the guys are very knowledgeable and may have seen the issue often and put you on the right track.

Why does my Chevy 350 backfire under load?

When high performance turbo engines are under load they use an excessive amount of fuel which then is transferred into the exhaust system once the throttle is let up on and the engine is de-accelerating. This is a normal event and there is no problem with this condition.

What causes an intake back fire in a car?

If the check engine or service engine soon light in on scan the computer for trouble codes. This will help locate the system that is having a problem and needs repair. An intake back-fire explosion can be caused by the fuel air mixture being to lean when the engine is demanding power.

What causes a backfiring exhaust on a 350 cubic engine?

Thankfully, because both of these components are on top of Chevrolet’s 350 small-block engine, checking them is quite easy. Backfiring is typically caused by an air/fuel mixture that is too lean, meaning the mixture has too much oxygen in it. First, check that the mixture screw (s) on the carburetor are adjusted properly.

Why did my GM 454 Backfire at WOT?

I replaced the in tank fuel pump last month thinking it was fuel starvation while going up hills at WOT (wide open throttle). The fuel pressure with the old pump was low showing around 8 psi on the pressure gage that I permanently mounted 3 inches from the throttle body on the pressure line.

What to do if your Chevy engine backfires?

You’ll want to have a Chevrolet technician take a close look at your vehicle’s fuel system if the air/fuel mixture in your engine is running lean and causing backfires.

What causes an intake back fire in an engine?

This will help locate the system that is having a problem and needs repair. An intake back-fire explosion can be caused by the fuel air mixture being to lean when the engine is demanding power. Every internal combustion engine runs on a mixture of 14 to 1 which is fourteen parts air to one part fuel.

What happens if you have a backfire in your exhaust?

In case the sensor is totally broken, you will need to buy a new one. A backfire appeared in your exhaust pipe can not hurt your beloved car immediately, but it can be a warning sign of a coming problem or a indicator to a more awkward issue.

What should I do if my GM 454 backfires?

That is the system with the 2 springs one on each side are good and that the arms the springs are connected to mover freely in one direction and back again when released. A drop of oil at each pivot point is good job while the rotor is off.

Can a backfiring on an engine cause damage?

Backfiring can cause serious damage to an engine if the problem is not quickly fixed. The problem can usually be traced to the carburetor or distributor. The carburetor delivers the air/fuel mixture to the engine, and the distributor ignites that mixture within the cylinders.

What causes a carburetor to go backfiring?

Backfiring is typically caused by an air/fuel mixture that is too lean, meaning the mixture has too much oxygen in it. First, check that the mixture screw (s) on the carburetor are adjusted properly.

What causes a Chevy 350 to backfire when idle?

If a main vacuum hose such as the power brake booster feed line has broken or failing off it will cause a lean backfire due to the additional air allowed into the engine intake manifold. This problem will be accompanied by high or low engine idle and a harder to push brake pedal than normal.

What causes a backfire in the exhaust manifold?

If your engines spark plugs are not able to fully burn the air and fuel mixture in the cylinder this can cause the air-fuel mixture to ignite in the exhaust manifold causing a backfire. If you are unsure of when your spark plugs were last replaced it would be a good idea to inspect them for carbon buildup and corrosion.