Forum Home
PC World Chat
 
Thread ID: 122814 2012-01-14 04:13:00 How to measure fuel flow rate The Error Guy (14052) PC World Chat
Post ID Timestamp Content User
1254038 2012-01-14 04:13:00 I was wondering how I could measure the rate of fuel consumption, namely on my cars but I also had a few other applications for it If I ended up buying a physical flow meter of some type.

Is it possible to read this information off the ECU? I'm guessing yes but it will probably require an proper OBD system that would be pretty darned expensive. I looked around a bit and found a lot of irrelevant info and some rather expensive lab quality flow meters. Fuel type is petrol although if there is one that does diesel too that would be nice (but not really necessary)

Cheers
The Error Guy (14052)
1254039 2012-01-14 04:37:00 I have read in car forums where off road car racers (in USA) "remap" their ECU's for fuel improvement. Some use laptops and software to input variables, but not sure how they would (or could) actually measure consumption.

There are apple mobile apps that supposedly measure consumption.
kahawai chaser (3545)
1254040 2012-01-14 05:22:00 "remapping" is pretty much re flashing the ECU, the electronic equivalent of tuning. To do this properly you need a cable that interfaces with the ECU and fully understand the ECU, usually people can't actually DIY tune the vehicle. It requires you to purchase the tuned files from a tuner/garage.

I was wondering because sometimes my car seems to chew through fuel where it is usually economical (flat motorway driving). Wanted to see how my driving affects consumption and see if there are any spikes in fuel consumption. Sometimes is lacks power but I doubt thats a fuel (flow) issue, got to do a service soon. Been away/busy so I haven't performed much maintenance other than fluids checks.
The Error Guy (14052)
1254041 2012-01-14 05:43:00 There is no fuel flow measurement in most cars that I can think of (Not sure about more moden stuff, say post 2005). The system is simply pressurized and there is a pressure relief value is the only thing monitoring that pressure and afaik that is mechanical rather than electronic.

I can think of a few cars that change fuel flow rates, Toyota Soarer is the one that springs to mind, IIRC it has an ECU for fuel control alone, stupid over complex system.

The measurement tool the old man has has a special banjo bolt that goes onto the fuel rail and measures it from there.

And remapping is quite complex, it's usually easier to go aftermarket ecu.
Alex B (15479)
1254042 2012-01-14 07:32:00 Some of the newer models have fuel flow done, comes up on a dinky little display somewhere on the dash.

No point getting an ECU for my car, its a 1.4 ltr so no point throwing money at it. Its wasted investment. Might do some work on the mitsu later on. Just gotta get funds and getting running nicely... its a 3.5 ltr so ill probably need a mortgage to actually drive it Took a peek under the valve cover and its all sludged up. Lots of thick oil build up in the vacuum lines that run through there too. Probably going to end up stripping the whole lot down and cleaning it out. Yuck.
The Error Guy (14052)
1254043 2012-01-14 07:44:00 Fuel flow (as in PSI) or KM/L?

I'm not sure why your average punter would ever want to know the fuel flow, it's not relevant information except for diagnostic purpose.
Alex B (15479)
1254044 2012-01-14 08:26:00 Flow as in L/PM, I thought PSI would be fuel press and KM/L would be consumption rate The Error Guy (14052)
1254045 2012-01-14 08:32:00 My guess is they use MAP sensor and some preset known values for that info. Alex B (15479)
1254046 2012-01-14 09:20:00 If you have an indicator in L/KM, you will very smartly find yourself driving without a roof rack, with air con off, and tires well inflated. It will happily tell you just how much those new spark plugs are saving you too. Gentler acceleration also shows up well. R2x1 (4628)
1254047 2012-01-14 09:28:00 Maybe start with a multimeter to do resistance tests for fuel injectors, sensors, cam sensor, coil, fuel pump, MAF, auxiliary air control, air regulator, throttle, leads, etc. Need specs though. kahawai chaser (3545)
1 2