Poor MPG in Mk1 1.4RT Clio

Level 10 User Joined: 04 Nov 2005 Posts: 575

Recently I've been getting pretty poor petrol consumption (over the last couple of months). I've only been getting 70 miles to Â£10 of petrol which works out at about 28mpg. I know for some of you this is OK MPG but I was definately getting better (around 35mpg) not too long ago.

I thought it may have just been me being too heavy with my right foot but since I topped it up with petrol earlier this week I have driven at low revs etc and not pushing it at all but I'm going to get about 75 miles max out of Â£10.

What sort of things could cause the fuel consumption to go down like this - is there anything I can check?

I was speaking to my unlcle (who used to be a mechanic) at the weekend and he said that garages should have something they can stick up the exhaust to check whats coming out and that should give an idea of what the problem might be - should most garages be able to do that and how much is it likely to cost me?

Site Subscriber Joined: 05 Jan 2005 Posts: 569

I find petrol consumption can be in your head a bit.

But anyway, try cleaning/replacing your Coolant Temp Sender.

Level 10 User Joined: 04 Nov 2005 Posts: 575

FincH wrote:

I find petrol consumption can be in your head a bit.

But anyway, try cleaning/replacing your Coolant Temp Sender.

Yeah I know what you mean mate and had wondered if that was the problem but I'm almost certain it's not. I'll be able to tell for sure if I go on a long drive at some point because previously I saw 49MPG out of the car on a long journey. Really I just want to see if there is any way I can check it's fuelling properly.

On another forum someone suggested adjusting the carb mixture but I don't know how I can do that and make sure it's set correctly - would I need something to monitor the fuelling in some way when adjusting?

Site Subscriber Joined: 05 Jan 2005 Posts: 569

I assume your car has SPI and therefore, afaik (could be wrong) you can't manualy adjust the fuelling.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

what car and engine might help!

Site Subscriber Joined: 05 Jan 2005 Posts: 569

It's in the title Chris... Laughing

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

yes i just saw that

CTS i'd go for but a good service might be needed

Site Subscriber Joined: 01 Mar 2004 Posts: 458

the CTS seems to be a cause of many faults, is it easy to give it a good clean?

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

yes but no point if it needs replaced.

Site Subscriber Joined: 01 Mar 2004 Posts: 458

just wondered got a spare one from old engine might clean & swap it over to see if it helps the problems i've had

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

worth a try

Level 10 User Joined: 05 Mar 2005 Posts: 570

On the EJ7 head, which is the CTS? Is it the smaller or larger of the two sensors?

Site Subscriber Joined: 05 Jan 2005 Posts: 569

It's the white one.

Level 10 User Joined: 05 Mar 2005 Posts: 570

light brown of dark brown Rolling Eyes

which one?

Level 10 User Joined: 04 Nov 2005 Posts: 575

Thanks for all the suggestions. I'll give the CTS a clean and see what happens.

One thing I've noticed is that over the last few days when the temperatures have been a bit higher (not freezing at night) I managed to get 45 miles out of Â£5!!! This was with quite a heavy right foot as well.

Would that agree with the idea of it being the CTS?

Site Subscriber Joined: 01 Mar 2004 Posts: 458

just to follow up changed CTS saturday morning and cars been running lovely, also added my new Hill power IK!! fuel economy is noticably better alread, and so far no engine fecking about.
How come such a simple sounding item can cause so many faults?

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

because it controls the entire fuel map.

Level 10 User Joined: 04 Nov 2005 Posts: 575

Just to double check - am I correct in thinking the CTS is the white thing in this photo

I just need to get at it now lol.

EDIT: Sorry about the tiny photo - it came up as huge first of all and I went to change it in my photobucket account and that's what happend.

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

yes thats it

Level 10 User Joined: 05 Mar 2005 Posts: 570

Mine is'nt white, one is a larger brass one and one is a smaller steel?!? one (I guess as it's rusted to crap).

Ideas?

Forum Moderator Joined: 02 Mar 2004 Posts: 19978

the brass/brown one is for the temp gauge.