5.0 bad fuel economy check list

[<RaBBiT>]

5.0 bad fuel economy check list

hey all i have been having pronlem with my 5.0's fuel eco for almost a year now. im just looking for a list of things that can cause this

i have a vs 5.0 its got a custom tune, 02 sensor replaced to a 4 wire, new rollmaster timming chain. how ever it does had a bad dent in the headers so thinking this is my problem.


anyway i hope u guy's can help me out cheers.

[Vee-ard]

the VS shouldnt take a 4 wire oxy sensor, because two of the wires are redundant? Could be your problem, but im not really a whizz with that stuff, so wait and see what others say.

[pillzor]

what type of milage are you getting ?

[<RaBBiT>]

18.00 per 100km's so last's maybe 3 days

[pillzor]

ouch , is that around town and cold runs?

[<RaBBiT>]

cold warm, blue red lol no matter how far i drive or how long or how short it changes between 17.5 to 18.00

[Vee-ard]

as far as I know, most common causes are oxygen sensor, temp sender unit, and any obvious fuel leaks

[crewsy]

maybe get the tune checked as well... did it get bad just after the tune or?? when did you notice it

[greenfoam]

if it's not doing 9.something on the freeway then it's stuffed. Well something is . O2 sensor/fuel pressure regulator are two common ones but it coudl be alot of things that are half worn out. If I done the tune it should be fine, better than stock

[Vee-ard]

yeah, I'd love to know what those things are on mine too. Just replaced the o2 sensor on mine, but still getting 500kms/60L pure freeway driving. (20kms in to work, 20kms out, all at 110kph). I'd like to push it to 600kms/60L and get the 10L/100kms

[greenfoam]

500 is not too bad for you since more than half your trip each way would be running cold (well cold in the Broome sense of the world probably isn't so bad as Southern Vic :P )

[Vee-ard]

I thought they warmed up sooner than that! thanks for setting me right foamy

[Cobez]

I'm currently getting 17.2L/100kms around town. I don't give a shit about what the cluster says though, it's all about what my fuel gauge says. I could drive 50kms like a nut, then 50kms like a nanna, and it will probably still go up.

I don't care about fuel averages, just about what my fuel gauge says. I barely use half a tank a week, and that's driving to and from work, to the missus house, around with mates, to JC meets etc, and that's with it copping a spray every now and then.

[<RaBBiT>]

its always been bad its had heaps of touch up tunes which is custom. i keep getting told to replace things and it will be sweet hence y i have new timming chain new 02 sensor. would my header play a roll at all?? there is a pic above

[Cobez]

Possibly, but good chance not. Like i said, i don't give mine a hard time, only occasionally, and mine is still 17.2L/100kms around town. I just worry about what the fuel gauge says.

I have a new 02 sensor, new plugs, leads, oil, oil filter, fuel filter, my headers and exhaust are dent free, leak free etc. Mine isn't logging any problems either and i run BP 98RON fuel on a Kalmaker ECU upgrade / dyno tune and i still get 17.2L/100kms.

Your computer / dash calculates your fuel average, so you could drive it hard for say 40 or 50 kms out of 10, then drive it like a grandma for 50kms, and it would still probably go up.

[<RaBBiT>]

i baby it 90% of the time and i use bp unleaded 95octane. and i can tell its using fuel the guage is always going down lol

[dazza410]

I got VS ute 5l auto I only get about 380k/55 litres, thats driving klike a nanna mostly on high way. I get an engine light every so often and i uses even more then, sound like the o2 sensor yer???

Only had for couple of months a blew auto box today any ideas on where to get decent rebuilt tough boxes and /or manual conversion kits. was a pipeline item as I want a strocker at some stage soon ideas, anyone?

Also I have read about engine tunes on the threads who and where and $$$

[crewsy]

just do a good service on it mate. are your spark plug leads old? they can get current jumping between them and the engine light can come on. do spark plugs, rotor button, oil, oil filter, air filter etc all in one go and your engine will love you

[crewsy]

Only had for couple of months a blew auto box today any ideas on where to get decent rebuilt tough boxes and /or manual conversion kits. was a pipeline item as I want a strocker at some stage soon ideas, anyone?

speak to Mal Wood if you want to do a decent manual conversion, especially if you want something reliable for a stroker