Clogged fuel return line symptoms

Proper fuel pressure is vital for engine operation and performance. Low fuel pressure results in a lack of horsepower, stalling, and a slow or no-start condition. A faulty fuel pump or a clogged fuel filter will result in lower than normal fuel pressure at the rail. High fuel pressure results in a rich air fuel ratio, because the increase in pressure forces more fuel through the injectors than required. A rich air fuel ratio causes black exhaust and high emissions HC's. These excessive hydrocarbons overheat and damage the catalytic converter.

A kink in the fuel return line will result in higher than normal fuel pressure at the rail. Test fuel pressure with a fuel pressure gauge. Check the service manual for the proper fuel pressure for the vehicle being tested. Find the fitting; it is typically on the fuel rail. If not, a special fitting from a fuel injection kit will be required.

After properly installing the gauge, secure it and turn the ignition key to the on position; it should indicate fuel pressure. Start the engine; the fuel pressure should remain the same. Snap the throttle and make dr peter hackett wiki it increases.

This an indication of a good fuel pump. Test a vacuum operated fuel pressure regulator's operation by removing the vacuum line while monitoring fuel pressure. The pressure should increase psi. A ruptured fuel pressure diaphragm will leak fuel into this vacuum line. Check with the manufacturer's manual for special procedures. Some fuel pressure regulators are electric and controlled by a control module PCM.

Study Tips Test Format Feedback. Fuel Pressure Proper fuel pressure is vital for engine operation and performance.If we can't tunnel through the Earth, how do we know what's at its center? A lady introduce her husband's name with saying by which can stop or move train what is that name. Give points yo advocate thst biology is linked with physics chemistry mathsmatics geography.

All Rights Reserved. The material on this site can not be reproduced, distributed, transmitted, cached or otherwise used, except with prior written permission of Multiply. Hottest Questions. Previously Viewed. Unanswered Questions. Fuel Filters. Wiki User Fuel lines become clogged in three basic ways: The fuel has something bad happen to it.

Diesel will wax and gel in cold weather. Some additives will melt this but really the only good repair is to warm the entire vehicle until the fuel returns to liquid, drain the fuel and replace with fuel good for the outside air temperature. The fuel is dirty and plugs the filter. Replace the filter, if the contamination was not all caught in the filter already drain and clean the tank Ice, in gasoline Petrol and diesel water can collect and on cold days cause ice blockages.

Methyl Alcohol marketed as methyl hydrate in Canada will clear most small contamination's and problems. Larger problems require warming the entire vehicle and removal of the contaminated fuel. Caution water in diesel fuel can cause engine and injection system failure!! A clogged fuel filter or fuel line will likely make your car sputter as if it is going to stall. Asked in Dodge Dynasty What is the problem with a 93 dodge dynasty that will not stay started? You may have a clogged fuel line or a clogged fuel filter.

A clogged fuel filter can actually cause a fuel pump to fail. This is a much more expensive repair than a filter. Asked in Brakes and Tires Clogged brake line repair? To fix a clogged brake line, first find the clog.

Then, remove the clogged line from the cylinder.The fuel return hose is a fuel system hose that is found on vehicles equipped with carburetors. Aside from providing a path for excess fuel to return to the tank, the fuel return hose also prevents vapor lock and over pressurization from occurring within the carburetor.

Vapor lock occurs when the fuel pressure or temperature rises too high the fuel can begin to vaporize and cause issues. Usually a fuel return hose is made out fuel resistant rubber, not much different from the rest of the hoses on the fuel system.

This leaves it susceptible to the same wear and tear that regular hoses experience, such as drying out and cracking. Usually a bad or failing fuel return hose will display a few symptoms that can alert the driver of an issue. One of the first symptoms of an issue with the fuel return hose is an excessive fuel smell. If there is any sort of issue with the fuel hose, either a leak, or some sort of kink that blocks the flow, it may cause the vehicle to produce an excessively strong fuel odor from the engine.

The odor may be a result of leaking fuel, or of the vaporization of the fuel inside of the carburetor due to vapor lock. A vapor lock induced fuel smell may also be accompanied with performance issues such as misfiresa loss in powerand fuel economy.

clogged fuel return line symptoms

Another symptom of a potential problem with the fuel return hose is carburetor flooding. If the fuel return hose becomes blocked or kinked it may cause the carburetor to flood from excessive fuel or pressure buildup. A flooded carburetor may cause engine stalling and hard starting until it is cleared, or enough fuel has evaporated.

If the fuel return hose becomes excessively worn or damaged, it may cause fuel leaks. A leaking fuel return hose may produce drips or puddles of fuel underneath the vehicle, as well as a noticeably strong fuel odor.

Fuel hoses play an important role in the operation and performance of the engine, and when they fail, aside from the performance issues, can even become a potential safety hazard. If you suspect that your fuel return hose, or perhaps another fuel hose, may be having an issue have the vehicle inspected by a professional technician, such as one form YourMechanic, to determine if the hose should be replaced. The most popular service booked by readers of this article is Fuel System Inspection.

Our certified mobile mechanics make house calls in over 2, U. Fast, free online quotes for your car repair. Schedule Fuel System Inspection. Service Area. Average rating fromcustomers who received a Fuel System Inspection. Strong fuel odor, engine misfires, and decreasing power One of the first symptoms of an issue with the fuel return hose is an excessive fuel smell.

Carburetor flooding, engine stalling, and hard starting Another symptom of a potential problem with the fuel return hose is carburetor flooding. Home Articles. The statements expressed above are only for informational purposes and should be independently verified.

Please see our terms of service for more details. Related Articles. Related Questions. My BMW i has smoke coming from the left side of the engine You could have a small oil leak or even a coolant leak.

clogged fuel return line symptoms

When the fluid drops on a hot surface, it burns or boils. Coolant and oil leaks are easy to distinguish if you can get where you can smell What does the fuel gauge show? The fuel gauge is located on the instrument panel, and tells you how full your fuel tank is. The gauge has an F Full on one end, and an E Empty on the other.The importance of cleaning clogged fuel injectors cannot be overstated.

But how to tell if your fuel injectors are clogged? Or faulty? Engine trouble is rarely easily identified, but there are symptoms for every issue, symptoms that everyone can learn to notice. Blocked diesel injector symptoms are similar.

However, once again it pays to emphasize the value of prevention.

clogged fuel return line symptoms

Proper maintenance schedule that includes regular use of injector cleaners either liquid additives or manual cleaning kits can go a long way in keeping your vehicles operating smoothly and reducing any repair bills down the road. Meaning, that sooner or later the fuel injectors on your fuel injection engine will get dirty and will get clogged to some extent.

This is especially true for machines that regularly operate for short periods of time like driving short distances in the city, or using farm equipment as multiple engine ignitions and shut offs will exacerbate the clogging. Unless of-course you make sure to maintain your vehicle properly. Though you can always choose to get your hands dirty and deal with the issues yourself, in which case check out this article: Fuel Injector cleaning — how to clean Fuel Injectors?

So any risk to the injector is effectively multiplied by the number of injectors in the engine. That in turn can cause the beginning phases of clogging or leaking to go unnoticed.

It is also worth mentioning that vehicles that use turbocharged engines are at a risk for uncontrolled, engine damaging detonations. It definitely makes sense to be proactive about this to save yourself a lot of money and headache in the long term. Fuel injector problems can be a serious matter. This is not to say that detonation cannot become an issue on other automobiles as well, as it definitely can.

However, for most regular fuel injected engines, detonation is more often caused by using low-octane gasoline.

At this point it is also fair to note, that all of the symptoms mentioned in this article can also refer non-injector related issues. Engines are complex pieces of machinery and there are usually several parts in the system that can produce similar symptoms when failing.

So what you might take for a bad fuel injector sound, can at times refer to bad spark plugs for example. However, the reason why I recommend fuel injector cleaners first, is because of their low cost and ease of use. Or better yet, avoid them in the first place by using cleaners regularly! And to see whether a cleaner has helped your car, try out our handy fuel consumption calculator! Check your mileage and keep track of how it changes. Changing car batteries is something most car owners have to do at one point or another.

An old battery may fail to start the car or run the various electronic accessories like the radio. A wrong type of battery may fail to keep the car powered up or not fit into the battery compartment at all. While it is important to clean the fuel injectors on our vehicles to keep them running smoothly, how exactly can we tell if the injectors need cleaning in the first place?

I can definitely understand that for a non-mechanics savvy individual, it can be quite the task to try to analyze and diagnose the health of an engine. While liquid fuel injector cleaners are often hyped as cheap and easy to use solutions for injector clogging issues, many consumers are still skeptical. It does indeed beg the question: can you solve engine troubles with the help of a 10 dollar product?

clogged fuel return line symptoms

Great article. I have a Dodge Ram Hemi 5. Have been having all of the symptoms above and engine light has been on. Took it in for a diagnostic and found evap leak with code for LDP pump so changed that out. Then we got a code for Lean code — replaced Intake Manifold gasket. Still have the same symptoms as above.

I know you mention it can be other things besides the fuel injectors so just curious what else it may be.So, Testing the fuel pressure regulator is a simple task that requires some minor equipment; and a short amount of time. Spend the money and get a good Fuel Pressure Testing Gauge.

Average fuel pressure can be anywhere from 45 psi to 55 psi. Most problems with fuel pressure are due to the pressure being too low. Fuel pressure that is too high can cause the engine to run too rich. Common causes of high fuel pressure include a bad fuel regulator or a clogged return line.

Consequently, You will need to perform two different tests to identify the reason for excessive fuel pressure:. Too high of pressure may result in over fueling of the engine. As a result, This can lead to a rough running engine; poor fuel mileage, and black smoke coming from the exhaust.

If your regulator is going bad, your car could display several different symptoms. Remove a spark plug and examine the end of it.

If it is sooty, it could be a sign of a bad fuel pressure regulator. If you find a plug in this condition, check the rest of them. A sooty spark plug could just mean the engine is burning oil at that head.

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If you end up replacing your fuel pressure regulatoryou might also want to replace your plugs. You can try simply cleaning them and putting them back, but if your engine still runs poorly, get new ones. Speaking of poor engine performance; if you are idling the engine and it is not running smoothly; change your oil filter and check your pressure regulator to repair bad fuel pressure. Another sign that your engine is suffering the effects of a bad regulator; is if you have trouble starting the car.

It will fail to turn over a few times before it actually starts. Having black smoke coming out of your tailpipe is a sure sign there is something wrong with your regulator. The normal color of any smoke coming out of the exhaust should be white or gray; not black, so if you see the latter, there is definitely something wrong. If you do, it could be a symptom of a bad fuel pressure regulatorwhich has allowed gasoline to leak into the oil system.

If not repaired quickly it will cause the oil to lose its lubricating properties.


As a result, damaging engine bearings.By gen4maximaMarch 10, in General Technical. Maybe the fuel line got crimped by bottoming out on something. Either way, gonna have to remove it Is this a car that sat without running for years? Maybe old gas dried out in the tank?

I had a plugged hard line on my "sat for 5 years in a field ". I sprayed carb cleaner in both ends of the line and let it soak for awhile, then hit it with compressed air.

Symptoms of Bad or Failing Fuel Injection Lines

I just kept doing this over and over maybe a dozen times until no more brown gunk came out. You may use most of a can of carb cleaner, but that stuff is pretty cheap. If you do have brown gunk in your line, I'm not sure you will be able to get any sort of wire or rod through it. Dried up gas is similar to hardened glue.

You need to dissolve it. I think acetone would work too, but spray carb cleaner is way more convenient. You should stick a couple of feet of rubber line on each end of your hard line if you do this, so you don't blow brown gunk onto your car. Just to update this, old gas had gelled ijn the fuel line. On awhich is the fuel line? The line on the SIDE of the tank, or from the top? The side is working supplying gas to the engine.

The top line is plugged. A manuel indicates the top line for vapors going to the seperator. Not a good thought!! I took it off and heated it Unblocked it Dont do it when its connected to the gas tank though Not a good idea believe me! You can post now and register later. If you have an account, sign in now to post with your account.

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Note: Your post will require moderator approval before it will be visible. Paste as plain text instead. Only 75 emoji are allowed. Display as a link instead.Posted on September 17, Tow your vehicle to a mechanic if you need to find out for sure. However, you should be able to narrow down the cause of your problem. Here are signs of a faulty or clogged fuel line, although the problem could exist throughout your fuelling system:. If you see smoke in your engine compartment, it is dangerous!

Faulty fuel lines can cause fuel to spray or leak out, and fuel that comes into contact with a heat source may ignite. Smoke could be the result of a faulty fuel line. Do not leave your vehicle running if it is smoking. Stop, shut off your engine, and walk away from the vehicle. A sputtering engine will likely damage itself. Brands Lines - To - Go View all brands. Site Information. Smoking Engine If you see smoke in your engine compartment, it is dangerous!

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