Vanguard EFI Problems And Troubleshooting Guide

To some, mowing can be an extremely relaxing task. If you haven’t done any mowing yourself before, it might be surprising for you to hear this- some people actually enjoy riding around in their riding lawnmowers, trimming down the lawn grass to their desired height.

However, to enjoy your time mowing, you need a lawnmower equipped with a reliable and powerful engine. And when I am talking about reliability, there’s one engine that deserves mention, the vanguard EFI.

Designed by Briggs & Stratton, the vanguard EFI series engines are a true masterpiece that can enhance your lawnmowers performance tenfold. But just like any other engine out there, there can be a few problems that crop up in it every now and then.

In this article, I will talk about some of the issues that you might have to deal with in your vanguard EFI engine and give you some troubleshooting tips to fix them. So, without further ado, let’s get started.

Common Vanguard EFI Engine Problems And How To Fix Them?

As I said already, the Vanguard engine is designed by Briggs & Stratton, and the solution to almost any issues that come up in the engine can be found in their engine troubleshooting guide. Be that as it may, I will still give you a clear guideline here to make things as easy as possible for you.

Now, I’ll be honest, issues in the Vanguard EFI engine are not as common as you might think. And there are certainly ways to prevent problems from ever coming up in the first place.

The easiest way to do that is to take good care of your machine and only rely on fresh, high-quality fuel for the engine. With that said, here are some of the problems that may crop up in your vanguard EFI engine and tips on how to fix these issues.

1. Engine Won’t Crank Or Start

A vanguard EFI engine is supposed to start up without any trouble. And if you suddenly notice that the engine won’t crank, you might be tempted to rush it to a professional. While that might be the right approach in some situations, there are a couple of things you can try before doing that.

Here’s a quick troubleshooting guide if your vanguard engine won’t crank.

• Disconnect the lead wires in the spark plug.
• Remove the wires and turn the crankshaft by hand. You need to go slow.
• Also, check the battery terminals and wires for signs of corrosion. Make sure the battery is fully charged.
• Turning the crankshaft manually should allow the engine to start cranking.
• If your issue is fixed, clean out the spark plugs, remove any dust, dirt, or debris, and put everything back together.

However, if your engine still doesn’t crank, there’s a chance that the cranking sensor in your vanguard EFI engine is positioned incorrectly. Typically, the cranking sensor is set up between the readings 15000 and 20000.

When, for some reason, the cranking sensor goes above 20000, it can prevent the engine from cranking. So, you need to check the position of the cranking sensor and reposition it if it is outside the optimal range. However, if that’s not what’s causing the issue in your engine, then you should take it to a professional garage.

You can go lower, but the sensor shouldn’t be under 12000. When the sensor is positioned around 12000, and the engine still won’t crank, then you should try the above remedies first. If the Vanguard seems not buzzing yet, call for professional help.

2. Engine Overheat

Overheating is a common problem in most engines and, if left unchecked, can quickly lead to more severe issues like engine failure or seizing. Like any other engines out there, the vanguard EFI by Briggs & Stratton can also fall victim to overheating.

Now, if you do not want to worry about an expensive repair bill, it’s best to deal with the issue as early as possible. Typically, there are two main reasons behind an overheating engine – dirt buildup or improper use of lubricants. Don’t worry; I’ll address both issues.

Dirt Buildup

An air-cooled engine like the vanguard relies on cooling fins and blocks to radiate heat away from the engine. But as you regularly use your lawnmower, dirt and debris can build up on the fins, which reduces its efficiency. Over time this can lead to overheating in the engine.

Since a lawnmower moves slowly, if the cooling fins get blocked, it will not get any air. Eventually, heat will get trapped, accumulate, and cause the engine function to throttle

So, the first thing you should do is clean the fins using a stiff brush. This will help you remove the buildup and help restore the cooling fin’s efficiency. If you use your mower regularly, you should make a habit of cleaning the cooling fins and air filters every 100 hours of operation.

This will help prevent overheating in the future and also ensure your mower runs in peak condition at all times.

Wrong Lubricants

Engine oils are an essential part of any engine. The job of engine oil is to dissipate heat that is generated from combustion and transfer it to the cooling block. And if you are using inappropriate engine oil, the heat transfer efficiency will take a hit. Before you know it, your engine might start overheating.

You see, lawnmowers move slowly, which means less airflow and more heat production. And when you add the summer heat to the equation, the chances of overheating increase exponentially.

To keep your vanguard engine cool, you need to use a high-viscosity lubricant that can enhance the cooling factor. Briggs & Stratton suggests using synthetic engine oil since these oils are designed to perform at high temperatures.

3. Inefficient Fuel Usage

Sometimes, you may notice that your lawnmower with a 28 or 37HP vanguard engine is chugging through fuel like a maniac. Other times, you may notice that it’s not running as efficiently as it did before. Both of these issues are a sign that there’s a problem with the fuel pump or fuel filter.

There is a chance that a pinhole leak in the fuel line is causing this issue, bottlenecking the flow of fuel. Another possibility here is that the carburetor seals are spoiled, making the mixture of fuel stale.

So, to deal with the issue, inspect the fuel line thoroughly, and look for any leaks or signs of damage. If the line seems worn, you should replace it right away. In addition, inspect and clean the fuel filters and install a fuel stabilizer for better efficiency.

4. Black Smoke From The Engine

It’s natural for a bit of smoke to come out of the engine when the engine oil burns. However, once black smoke starts coming out, that is an indication that something is wrong with it.

Typically, black smoke is a sign of low-grade engine oils or a faulty gasket. Here are a couple of things you can try to eliminate this problem.

• First, switch to better engine oil immediately. This should fix your problem in most cases.
• If the gaskets are faulty, you need to replace them. Repairing them isn’t an option.
• If the crankcase is leaking, then you need to repair or replace it. Also, check the condition of the cylinders and replace them if needed.
• Check the fuel condition. If it’s stale, replace it right away. Using high-quality fuel will also increase your mower’s fuel efficiency and performance.

Frequently Asked Questions

Here are a couple of questions that people have asked me in the past about the vanguard EFI engine.

Are Vanguard Engines Good?

Yes, vanguard engines are quite amazing. They have been around for quite a while now, and their huge popularity should be a clear sign of how good and efficient they are.

How Long Does A Vanguard EFI Engine Last?

Vanguard EFI engines by Briggs & Stratton are designed to withstand a lot of abuse.
While I can’t give you an exact timeline of how long they will last, as how you use them plays a huge part in it, you can expect at least 2000 hours of use without any hassle. Needless to say, taking care of it properly will further extend its lifespan.

Final Thoughts

Vanguard EFI engines are the best creation of Briggs & Stratton, and if your mower comes with one, you should be pretty happy. They offer excellent performance, and their efficient fuel consumption means less upkeep cost for you.

However, once they start acting up, it can get pretty frustrating for the user. And if you neglect the problem and don’t tackle it the first chance you get, there’s a good chance that it will turn into an expensive repair bill before you know it.

I hope my in-depth guideline of the different vanguard EFI problems and their fixes could help you get the most out of your lawnmower. Good luck!