VP Fuel Economy Opinions
Hey guys, Got a VN wagon with VP running gear. When i used to drive it 8-9 months ago i was getting 14-15 l/100kms after i changed my O2 sensor (was getting 18-19 before hand). No shes getting > 28l/100kms.
I pulled out the O2 sensor and was completely covered in black stuff, so cleaned it off but hasn't helped.
Wondering what else can be changed to help fuel economy? I know my O2 sensor has to be changed, but i cant for the life of me figure out why its gone bad so quicky (only done 5,000-10,000 kms). ATM cars getting ~200kms to a tank freeway driving :|
Apparently fuel pressure regulator and some vac lines can be the cause, but i have no idea on how to check these.... Any help is much appreciated
GRA = REAL HP
changed your 02 ? new ones fitted or second hand ? how did you clean the 02 sensor's
I changed it with a brand new one when i changed it a few months back. I cleaned it with a steel brush + air a week ago when i pulled it out to check it.
holy crap thats bad economy 0_o
I thought my VP was awful at 13-14L/100
GRA = REAL HP
ok check your map sensor and fuel pressure reg vacum line either one with a air leak could cause a over rich running , Faulty ECT sensor can give incorrect reading to the ECM and run it in rich mode too , a faulty injector dribbly injector , how well does the engine restart after sitting for say 30 mins ?
Engine starts fine every time. Would you happen to have a diagram of the fuel pressure reg lines? And MAP sensor is in the TB isnt it? I cleaned out the throttle body really well (along with the TPS) a few months back.
How can i check for a faulty / dribbly injector?
GRA = REAL HP
the map sensor vac hose is off the throttle body where it bolts to the manifold pointing directly at the firewall , the fuel pressure reg vacum line is off the inlet manifold neck find the pressure reg and trace the vacum line , to check for dribbly injectors unbolt the fuel rail and lift the injectors just out of the manifold prime the fuel pump aleast twice then run your finger under each nozzle and check for wetness . did you remove the TPS sensor ? is it refitted as it came off
Ill have a look tomorrow since ive got the day off. One thing though, Off the throttle body there are 2 black pipes (one larger than the other) running to a black canister of some sort at the front of the car. These are very loose and can be taken off with my pinky.. Could these have something to do with it?
GRA = REAL HP
those hose's are for the carbon canister and are only ported vacum any way , replace the rubber hose if your worried about air leaks
Ok bit of an update. I was outside today working on the car. Pulled apart the throttle body gave it a good clean, along with the IAC and TPS. The pipe connecting the throttle body to the MAP sensor was pretty buggered on both ends, easily coming off and frayed with cotton wire hanging of it. Cut it back further and re attatched and its nice and solid now.
The black pipe going from the fuel pressure reg to the manifold (just after throttle body) was the same, but was too short for me to just cut and reuse, so i had to buy a replacement.
Had a look at the O2 sensor, completely covered in crap, couldnt even see the fins in it! It also had something loose inside it that was rattling around. Threw it out and put the old one i still had laying around back in (half working is better than not working at all!) so ill have to get that replaced. Throttle body gasket was torn, so i replaced that too. Seems to idle better now. Ill have to wait and see how she goes for petrol.
Havent checked the injectors yet, ran out of time.
anything else i can try?
good stuff
that o2 sensor was totaled by the sounds of that
hey mate i had the exact same problem a few months ago. i ended up trying quite a few different things but in the end what seemed to fix it was new spark plugs and leads. the old spark plugs were absolutely ****ed and i just replaced the leads while i was at it cos they hadnt been replaced in a good 2 years or so. so if your spark plugs and leads are getting pretty old it wouldnt hurt to give them a shot if you got some spare cash hanging around. also im not 100% on this but ive heard from many people that the hose going from the throttle body to the MAP sensor should be kept the same length, im not sure why but yer just what ive heard, maybe someone else reading can shed some light on this? if you just head down to repco or somewhere and take out that hose in the carpark, take it inside and they'll be able to give you a new hose (usually you have to buy it in 1 metre lengths though). just another thought, well hope all goes well mate, good luck
When i say Cut the MAP sensor hose, i mean i cut literally .5cm - 1cm off each side. Just enough to get to some fresh hose
Also, spark plugs were changed ~ 13-14 months ago, so probably due. Leads... God knows when they were changed. I might have to check them with a multimeter.
Hybrids. Cars for fools.
i had fuel economy troubles similar to yours, i changed my o2 sensor and cleaned out my fuel tank and breather lines and i get an easy 400km to the tank doing short trips around town delivery driving and not driving like a granny.
Almost not here!
I'd put a new temp sensor infor the ECU - if the ECU thinks the engine is cold it will dring the petrol in no time.
White 05 V6 VZ Executive - Thrashed Ex Telstra car
and 3 Dangerous non ABS VN's
I have a vn thats driving me nuts .. Lucky to get 300 ks .. but i have replaced 02 sensor (new) coolant temp sender, new leads and plugs, replaced the cluster to a LVL2 cause I rekon LVL1 are crap and the fuel gauge wasnt the best either, oil and filter, fuel and air filter, next is to change the coil pack from the series 1 to the series 2 (seperate coils) and replace all the lines on the tank :S and this thing doesnt blow smoke at all .. it has slightly improved but nothing worth jumping up and down for .. if i get something .. ill let you know
Yeah me too. I had enough so I am changing every thing minus the shell and diff. no joke I am doing it :|
Originally Posted by Vlad01
Dude, So would i if i had another shell .. but i'd prolly buy an "X" series falcon or a "H" series holden .. that way i dont have to worry about stupid computers and TPS and IAC and so on .. :P
Do get me started on carbies!
Hahahahahaha .. they arent as bad as injected POS's but then again!! :P
Posting Permissions
LinkBack URL
About LinkBacks
Reply With Quote