really poor fuel consumption

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dylan5084
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really poor fuel consumption

Post by dylan5084 »

Ok so Ive just put the car back on the road and been driving a little spirited, but I've managed to use half a tank of fuel in 65 miles!

my idle is really high about 1100 rpm, it randomly drops to 900rpm when it feels like it after A wee drive. But usually at 1100-1300.

I replace the vacuum hose for my fuel pressure regulator valve, could this have raised my fuel line pressure causing higher consumption, it does spit flames when pushed.

What pressure should the fuel lines be at, at idle and on throttle?

I'm sure I had the high Idle at the end of the year last year too.

Could my lambda sensor be causing it?
Mikey637
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Re: really poor fuel consumption

Post by Mikey637 »

If you've just put It back on the road then I'd suggest checking the callipers are free moving
Peter Gidden
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Re: really poor fuel consumption

Post by Peter Gidden »

dylan5084 wrote:Could my lambda sensor be causing it?


Quite possibly. Get a CO test done. If around 5% you need a new sensor.
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

Yea the calipers are fine, do I just book it into any not station n get the emmisions tested for that peter?
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

My mate gave me a fuel pressure regulator with a gauge and I've set the pressure to stock, strangely it's cured my misfire when cold and my idle is now 1000rpm fuel consumption is up slightly but could be better, I've got an mot at the end of May so I'll get the emmisions checked then and if it's up at 5% I'll get the lambda changed. My mate say it still reeks of fuel when I floor it and he's behind me

Must of Been a faulty fpr or something!

Should the idle be at 900 rpm? I'm going to recheck my timing again when I find the light
bobhatton
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Re: really poor fuel consumption

Post by bobhatton »

dylan5084 wrote:My mate gave me a fuel pressure regulator with a gauge and I've set the pressure to stock, strangely it's cured my misfire when cold and my idle is now 1000rpm fuel consumption is up slightly but could be better, I've got an mot at the end of May so I'll get the emmisions checked then and if it's up at 5% I'll get the lambda changed. My mate say it still reeks of fuel when I floor it and he's behind me

Must of Been a faulty fpr or something!

Should the idle be at 900 rpm? I'm going to recheck my timing again when I find the light


Set the timing to 8 deg btdc, you will have less chance of the engine running under the control of the knock sensor then. Also you must run on the highest octane fuel again to stop knock
Designer for turbo set ups on F1 cars, and Nitrous Oxide Systems of the USA in the 80s
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

Usually run it on tescos 99 or shell v power.

How to I go about setting it 8btdc?

I've also got an apexi safc coming for it so, Id want to have Every other thing possible set right before I put it into the tuners
Ryan S
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Re: really poor fuel consumption

Post by Ryan S »

any MOT station will do your emissions for a tenner or so, Better to get on top of all that now before MOT time mate, that way you can still drive the car around :thumleft:
thomp1983
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Re: really poor fuel consumption

Post by thomp1983 »

if your mot's due the end of may then book one for next week, you can put it in a month early, if it fails you still have until the expiry to repair it
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

Is it the markings on the crank pulley that are btdc?
gnzyza
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Re: really poor fuel consumption

Post by gnzyza »

thomp1983 wrote:if your mot's due the end of may then book one for next week, you can put it in a month early, if it fails you still have until the expiry to repair it


I thought if it fails the test before the anniversary then you have no MOT
thomp1983
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Re: really poor fuel consumption

Post by thomp1983 »

Nope a in date mot certificate is a valid mot regardless or at least that's the opinion of every tester ive asked and I've never had any issues with the police and i can't remember the last time i had a car pass first time
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

thomp1983 wrote:Nope a in date mot certificate is a valid mot regardless or at least that's the opinion of every tester ive asked and I've never had any issues with the police and i can't remember the last time i had a car pass first time



Yea this is correct, I done it with my Volvo this year, and double checked with the guy that I could drive it when It had failed
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

right so ive changed the fpr and set the fuel pressure to stock, and it runs sweet now, idling at 900-1000rpm when warm and fuel consumption is better, but ive been told i need a 1:1 fpr, so when i get this, it should be better again. ive still to set the timing to 8btdc
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

I've now fitted a 1:1 Sytec fse valve, I've also tested my lambda sensor as per the bgb, and I recon it's goosed, get 5v at tick over but 0 if I touch the accelerator.


http://www.imoc.co.uk/forums/viewtopic. ... highlight=
griffo20022
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Re: really poor fuel consumption

Post by griffo20022 »

Check your engine coolant temp sensor also! When we first got Jess's MR2 it was horrendous Mpg (about 20) I tested the resistance on the sensor and was reading way too high! A new £10 sensor from eurocarparts and now we're upto around 35mpg. Defo worth checking if it's never been replaced at all :)
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

I changed the ecu temp sensor last year
griffo20022
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Re: really poor fuel consumption

Post by griffo20022 »

Arrr fair play at least that's one thing crossed off the list :)
dylan5084
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Re: really poor fuel consumption

Post by dylan5084 »

So I've fitted the o2 sensor, and the car seems different but when I do the bgb test it's still the same, and next step is change ecu!

Anyone got a spare rev 2 turbo ecu I can try before I buy? Or to just try see if it is that [Brick wall]
LukeSi
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Re: really poor fuel consumption

Post by LukeSi »

Have you tried cleaning the MAF?
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