We’re rewarding the question askers & reputations are being recalculated! Read more.

Questions tagged [fuel-system]

Fuel system covers the components of a car responsible for fuel delivery; tanks, pumps, filters, pipes. Questions on carburettors and injection systems have individual tags

Filter by
Sorted by
Tagged with
24
votes
4answers
375k views

Symptoms of Lean or Rich carb settings on a motorcycle

I have a 1981 Yamaha XS650. I recently put in K&N stock replacement filter (ie, they are in the airbox and conform to the size of the original), however they may be leading to a leaner mixture ...
77
votes
10answers
44k views

What are the benefits of premium (high octane) petrol?

Here in the UK it's common for petrol (gas) stations to offer both regular and "premium" unleaded petrol. The premium stuff is (naturally) more expensive, and I've often wondered what the actual ...
61
votes
6answers
268k views

How long does it take for gas to go bad?

Approximately how long does it take for unleaded gasoline in the tank and fuel lines to become unusable in a car that is not being used? What causes this, and what can be done to prevent or remedy ...
28
votes
9answers
118k views

Will higher octane fuel improve gas mileage?

I've heard from some people that high octane fuel will increase gas mileage. Around here, we have the basic unleaded(87), mid-grade(89), and premium(93 or 91). I've been using the basic 87 unleaded ...
12
votes
1answer
74k views

What is seafoam? What does it do? How do you use it?

Mech's seem to get a real rubbery one about Seafoam. Is it just fuel additive, like something similar to Lucas Oil? Do I just pour it into my gas tank as a gas treatment? What will it do/help ...
10
votes
2answers
6k views

Why is the engine on my Royal Enfield Classic 350 shutting down?

After travelling 7-8km on my Royal Enfield Classic 350, the bike acts as if the fuel is finished & the engine shuts down, but it starts again when I pull the accelerator. What could cause this ...
84
votes
11answers
92k views

Does the amount of fuel in the tank matter?

As long as there is some fuel in the tank, does the fuel level matter? In other words, is it advisable to make sure the tank is mostly full most of the time, or is this just silly? In other words, are ...
22
votes
1answer
26k views

LTFT and STFT values are off and don't make sense

Car is a 2015 BMW M5 and it has an aftermarket CAI and a catback (slip on) exhaust. No other performance mods or tunes. About 6-7 months ago, I bought a Kiwi OBD-II reader, simply out of curiosity ...
17
votes
2answers
303k views

What happens if you put the wrong kind of gas in your car?

I (like most people) just use regular unleaded gas in my car and always have. But once I accidentally put in the premium kind, mixing it with the unleaded that was already there, and I thought for ...
17
votes
2answers
6k views

how to optimize fuel consumption by changing the rear differential ratio?

Is it possible to improve the fuel consumption (decrease it) in my van by changing the rear differential ratio? I would like to optimize it for low-speed driving about 40 km/h (25 mph). Is it true ...
11
votes
2answers
1k views

Motorcycle Four Body Carburetor Synchronization Balancing

I would like to adjust four-body carbs by myself, in order to avoid spent money every time. What are the basic rules, tools and secrets of synchronizing multiple carburetor bodies?
15
votes
4answers
12k views

Difference between high octane and low octane?

What is the difference between high octane and low octane fuel? I'm not asking if one is better than the other for my vehicle, specifically, but rather what occurs differently both scientifically and ...
14
votes
6answers
27k views

How to improve fuel economy in high-mileage car?

I'm driving an 2003 Acura TL 3.2 with 177K miles on it. I bought the car with 110K miles on it. It seems to me that the car is not getting the same fuel economy that it did when I acquired it. I ...
11
votes
6answers
30k views

Why does a diesel sound like that?

My car is in the shop for a repair, and they gave me a loaner. It's a Chevy Cruze Diesel. Sitting on the driveway, my wife said, "It sounds like a truck". It does. So what exactly it is about ...
5
votes
2answers
4k views

Lean Fuel Code on V10

I have 1999 V10 Ford chassis on a 2000 Coachman motorhome. Engine starts great when cold, runs great, idles great, no skipping, missing, etc. Problem is that after driving more than 30 minutes or so ...
4
votes
8answers
25k views

When given a choice between octane 89 and 93, which should I choose?

I just recently got a 2005 Volvo S40 with a turbo engine; I want to take good care of it, so naturally, when the instruction manual recommends 91 octane fuel but says it takes a minimum of 87, I have ...
8
votes
3answers
55k views

Are fuel system cleaners (like Gumout) worth using regularly?

Are fuel system cleaners (like Gumout) worth using regularly?
16
votes
5answers
79k views

Can I use lower octane fuel at high elevation?

Here in Colorado, gas stations sell "regular" gasoline which is rated at 85 octane ((M+R)/2). In most of the rest of the US, 87 octane is the lowest grade available. (As noted previously, higher ...
16
votes
13answers
253k views

Is the ECON button just a placebo?

I recently bought a Honda Civic that had this in the car: I have no idea what it does, and how it's supposed to help. Even Honda's website is ambiguous, just using a lot of fuzzy words to describe ...
10
votes
3answers
4k views

Cleaning fuel injectors?

I took my car (2006 Honda Civic) to firestone to get an oil change and they told me I should get the fuel injectors cleaned. I was in an Advanced Discount Auto Parts store the other day and I noticed ...
2
votes
0answers
2k views

Fuel Consumption and other Fuel related data from basic OBD-II parameters [duplicate]

I want to know how can i obtain the values of Fuel Consumption, Fuel Economy and other fuel related information from basic OBD-II parameters like Vehicle Speed, RPM, TPS etc. I have noticed that not ...
6
votes
0answers
216 views

1993 Merc 300SE always stalling soon after startup, fuel pressure tests > 50psi

From the moment car starts to the moment engine stalls, which is about 40 - 60 seconds, fuel pressure is always above 50 psi. Can I safely conclude stalling is not caused by fuel system problems? I ...
5
votes
1answer
248 views

Do I have a fuel pressure or injector problem, or am I just chasing ghosts?

I just did a fuel volume test on my 98 Mazda 626 2L GF. According Tim Giles book Automotive Service: Each injector is energized for 15 seconds... Variations of more than 5 ml calls for replacement ...
5
votes
1answer
3k views

Can I use ethanol instead of petrol in my car?

I have a 2001 Ford Focus (EU/UK spec) and I'm planning a road trip to Europe. My research shows that they serve up something called E85 at their petrol pumps in addition to petrol and diesel. I've ...
3
votes
1answer
859 views

Do fuel pressure regulators allow some fuel to flow even when not turned on?

I'm completely rewriting this question since I really wasn't clear before. When discussing a fuel system with a return line and a vacuum operated fuel pressure regulator such as this: Where it says "...
2
votes
2answers
51 views

Fueling vehicle issues

Every time I go to pump gas in 2009 ford mustang. Almost every gallon that pokes in to tank makes the nozzle trigger pop back like if it was full. It is annoying to hold it and still pops back out. ...
1
vote
2answers
1k views

OBD-II Fuel type and level of Monofuel Cars

I'm making an application like Torque and i have some issues with commands of Fuel Type and Fuel level with cars that use only one type of fuel like, Only Diesel or only gasoline. With car Bifuel ...
6
votes
4answers
3k views

Does the tachometer provide any indication of fuel usage?

So, I'm driving along on the highway with the A/C blasting when I notice the price of gas. It makes me think, "what can I do to increase my fuel efficiency?" Some of the tips I've heard have included ...
5
votes
3answers
59k views

What would cause a car to lose power a few seconds after starting, then run normally?

I start my 2003 Honda Civic each morning and drive to work. A few hundred feet down the road, the engine will sometimes behave as though it is running out of gas and lose power momentarily. It doesn'...
24
votes
5answers
140k views

Why should the fuel petcock valve be turned to “Off” position when not using the vehicle?

It’s mentioned in the user manual of my motorbike, that when not using the vehicle, I should turn the petrol tap (the one that has three positions “On”, “Off” and “Reserve”) to “Off” position. I don’t ...
8
votes
5answers
29k views

Doing my own fuel induction service - how to, and how difficult?

I was recommended to get a fuel induction service for a 2002 V4 Camry, and am considering doing it MYSELF. The reasons for considering this are: My car idles a bit rough, especially when the AC is on....
8
votes
5answers
72k views

What happens when you run out of fuel?

My question is specific to diesel or gasoline (petrol) engines. Many people told me that it is very bad to run out of diesel since it can damage the engine and it's difficult to re-engage it ...
7
votes
3answers
63k views

Why does my gas not fill all the way?

Same as the title. I have filled twice, different stations, both fill to just over 3/4 and stop. I am not sure if this is the gauge or something with whatever magic tells the pump to stop. Is there ...
7
votes
2answers
23k views

What are all the different types of fluid in a car and a short summary of their use?

A fluid is defined as anything that flows, hence for our purposes a gas or a liquid. I know that there is fuel, engine oil, engine coolant and brake fluid. Also air is normally taken in through a ...
5
votes
1answer
635 views

How to calculate fuel consumption and CO2 emission on flex fuel cars using OBDII data?

Here is the thing: I'm trying to estimate the fuel consumption of cars using OBDII data. It's quite simple if we can treat each fuel and its stoichiometric air fuel ratio separately, but when it turns ...
5
votes
2answers
217 views

Intermittent stall at idle

I have a 98 Saturn sw2 with a recent problem. Two times now it has stalled while idling and when it doesn't stall it floats near 500 rpms (Usually 750 - 950). The first time, it would start and just ...
4
votes
1answer
1k views

Do injectors leak or injector seals leak?

Car: Audi S5 2008 I have a problem in my car where sometimes my car will be hard to start after driven for a while. Normally if I floor it close to where I stop the car, it's harder to start. When I ...
3
votes
4answers
12k views

Slow acceleration, high fuel consumption after spark plug change

I have a 2000 Ford Ranger 4.0 L V6 4x4 model. I recently was having some problems with the truck idling too low when cold and I decided to change the spark plugs. I put in 4 out of the 6 new plugs and ...
1
vote
2answers
758 views

Calculating fuel flow rate through obd || sensor not supporting 015E and 0110 commands

I have been working on a project where i want to calulate fuel flow rate using data from the obd2 sensor. The car on which i was testing didn't support the pid 015E which is for fuel flow rate. Then i ...
16
votes
6answers
44k views

How to properly dispose of old fuel?

I have some old 2 stroke mixed gas I need to get rid of. This could also apply to old fuel removed from a sitting car or any vehicle for that matter. What is the proper way to dispose of this? Are ...
10
votes
3answers
33k views

How do I safely siphon gas from a tank?

Our 2003 Windstar was recently totaled in an accident (everybody's ok). This happened the day after we filled the tank. Before we hand over the car to the insurance, we'd like to get the fuel out of ...
9
votes
1answer
283 views

Lada Niva 1700 Carburetor Model

The compression is good and does not burn excessive oil .Fuel consumption has dropped from 8 kilometers per liter to 5.7 kilometers per liter.Same driving cycle same location. What should I look for?
9
votes
1answer
2k views

What is the yellow precipitate in my outboard's carburetor?

I've got a 2008 Tohatsu 9.8 HP four stroke outboard. My low speed jet keeps getting fouled and on several occasions, I've found yellow almost crystalline "growths" for lack of a better word inside ...
9
votes
3answers
3k views

What are the causes of fluctuating intake manifold vacuum

I have a 2005 Honda CBR600 F4i which suffers from occasional hesitation at low rpm when accelerating. I also get occasional fault codes from the ECU indicating a vacuum leak. Today I connected a ...
8
votes
1answer
4k views

What is the “Activated Carbon Cannister”?

Why do I have an "Activated Carbon Cannister" in my unleaded/petrol car? What is it's purpose? How does it work? Do I need to do anything to maintain it? I would like a general answer, but my car ...
8
votes
2answers
3k views

How to know how much fuel is left when the light turns on

In general, where can one find information about the quantity of fuel that is left in the vehicle's tank when the warning light turns on? More specifically, in a Suzuki Swift GLX (auto) 2010 model?
7
votes
2answers
825 views

Are there any modern diesel engines that require electricity to continue running?

I was reading this question about an owner checking the alternator by disconnecting the battery, which is an easy way to validate on a gasoline engine. The single answer assumes that the OP is ...
7
votes
1answer
1k views

Vespa PX 150 Fuel and Carbon issue

I am using Vespa PX 150.It is using Contact Point system. The issue is it is consuming fuel more than average and the plug is full of carbon after approx 50 Km.The engine not start unless I clean the ...
7
votes
1answer
2k views

2009 Hyundai Sante Fe - gas smell in cabin after replacing fuel sending unit. has been repaired 4x's now

Fuel sending unit replaced. Since then it has gas smell in car. It has been redone by mechanics four times now but still has a gas smell when the gas level is in the first quarter of the tank. Cap ...
7
votes
1answer
12k views

Why is there a hissing noise when I open my petrol cap?

When I fill up with fuel, there is often a loud hissing noise, as if you are opening a bottle of fizzy drink or something whenever I unscrew the petrol cap. It also seems like there are vapours ...