bad mpg!!!

Site Subscriber Joined: 28 Oct 2005 Posts: 247

ok chaps having afew problems all at once another i noticed the other day was mad mpg its gone from 29.9 to 21.6!!!!

things that i have changed are:
plugs, leads, cambelt+pre tensioners, water pump,

plus cleaned throttle body and ICV (but have another on its way as i have a high idel)

also have a CTS (coolant temp sensor) to pick up tomora too could this be linked to bad mpg????

im thinking lamba sensor could be on the blink but just thought id ask your advice before i go get one

as u can c if not much good with the reno just yet as its all new to me as im use to the rover and honda engines and this is my 1st car away from the rover badge so im just saying sorry for asking so many questions now lol

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

A dodgy CTS could potentially cause bad MPG as well as bad idling.

Site Subscriber Joined: 28 Oct 2005 Posts: 247

ok well all being well should be solved by tomora tea time yay Very Happy

Spammer Joined: 27 Jul 2004 Posts: 5717

as far as i know the trip comp looks like its doing calculations based on the total milage and the total fuel consumption at all times .
so say you are driving and it shows 21 mpg does not necessarily mean you are doing 21 mpg at that second,
i always check the milage i do and compare it with the fuel burnt . and that makes it more reasonable considering i ragged the car ,driven on the motorway etc

i might be wrong

Site Subscriber Joined: 10 Jun 2004 Posts: 2317

Correct schakal, its an average mpg from the time is was reset, not actual.

Site Subscriber Joined: 28 Oct 2005 Posts: 247

ok since i have had the car its done 29.9 mpg then over last couple of days i driven no more or less then normal and its dropped almost 8mpg!!! might no sound much but it is to me

Site Subscriber Joined: 29 Mar 2005 Posts: 731

I noticed on mine that if you are sat with the engine running in traffic it goes down a fair bit.

I made a couple of stops recently and left the keys in the ignition. Came back and the mpg had gone down by 7.4 or summit, with the engine off!

Site Subscriber Joined: 28 Oct 2005 Posts: 247

but mine has dropped from running not when stood still ie last friday it read: 29mpg then checked on monday it read 24mpg then so on till its at 21 now

so im going to replace them CTS and fill up to top reset computer and c how it goes

Site Subscriber Joined: 05 Apr 2004 Posts: 1141

I wouldn't go by the MPG computer so much, see how many miles you get out of a tenner and work it out.

Spammer Joined: 27 Jul 2004 Posts: 5717

i used to get(a few months back)about 300 miles starting with 12 gallons untill the light come on at 1 gallon left
11gallons = 280/300miles thats less than 30mpg but it is due to the route (7miles to work ) and the way i drive .
i have also seen 37mpg on the motorway going down to devon with 4 adults and the boot full of stuff .
there is not much to complain tbh ,now its winter you will end up burning more fuel due to the cold weather as well

1.9 td is your best bet for fuel economy Smile

Site Subscriber Joined: 05 Apr 2004 Posts: 1141

I managed 37MPG when I picked up my valver on the way back, now around town I see 32 usually.

It could be my imagination but I'm sure my MPG has gone down now I've fitted a new CTS

Site Subscriber Joined: 28 Oct 2005 Posts: 247

well fitted my new CTS today fitted it and all i can say is that so far fingers crossed the stalling at juctions has stopped yay no more looking like a learner driver lol

mpg still not gone up so ill give it a few days then have another think about it shoudl get a working ICV tomora will tey that too

happy am i now so cheers all for ya help

Site Subscriber Joined: 28 Oct 2005 Posts: 247

little up date:

no more stalling yes but it still hesitates from 2.5-3.5rpm like its kangerooing then it goes fine after 3.5rpm and this is in any gear and any speed i can be doing 60 in 4 and it will still do it!!

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

TPS could be up the spout then...

Site Subscriber Joined: 28 Oct 2005 Posts: 247

is that the red thing ??? on side of throttle body??? lol

Forum Moderator Joined: 18 Feb 2004 Posts: 7432

Yep, that's the one Laughing

Don't arse about with it unless you've got another one to go on though, it's set in the right position at the factory and you need a multimeter to set up the replacement

Site Subscriber Joined: 28 Oct 2005 Posts: 247

i ent toucking nothing ill get another working throttle body and do it that way Very Happy

Site Subscriber Joined: 28 Oct 2005 Posts: 247

another up-date lol

fitted another ICV and the car has stopped hesitating completlt nut idel is at 1500 rpm when warm and u dont want to no ware it idles when its cold Embarassed

so i think that the idel screw has beem messed with at some time and reading through some of the knowlage base posts it seems that all i got to do is turn the screw one way and idel should change so my question is do i play with the idel when the engine is warm or cold??