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Omega Help Area => Omega General Help => Topic started by: Essex Pete on 07 December 2009, 13:43:20

Title: Poor MPG on 2.5TD
Post by: Essex Pete on 07 December 2009, 13:43:20
Recently my MPG has been getting less and less.  A few weeks back after passing its MOT i serviced my car.  New filters and oil change, including a full pot of diesel magic in the fuel filter.  Since then i have been getting less and less MPG.  When i got the car i could go nearly 600 miles to a tank, i am now struggling to get 400 miles, which equated to less than 30MPG.

Now i noticed this week that with the cold weather it hasnt been getting up to temperature, so i have a new thermostat on order which will be fitted at the weekend along with a full coolant flush. 

It seems strange to me that it has got so bad since i did the service.  I know the stat wouldnt have been helping, making the car run  on cold run (rich), but is there anything else that could be an issue.

Also, when cold, the engine sometimes hesitates and the eml flashes on.  This only happens when you lift off the throttle.  If you press the throttle again quickly the car will try to throw you through the windscreen.  This seems to happen as i change gear and the revs drop past 2000-1500 rpm.  If i let the revs drop to idle before letting up the clutch it is fine, but if i mistime it, it seems like it is choking the engine.

The eml light doesnt stay on, just flashes, and there are no fault codes stored. 

Sorry for the essay, but i would like to try and fix these issues sooner rather than later, its costing a fortune in diesel
Title: Re: Poor MPG on 2.5TD
Post by: MickAP on 07 December 2009, 14:42:19
Have you checked the obvious like.......diesel leaks around filter seal/collar, leak off pipes and air filter box and connecting hoses/pipes. Have you accidently dislodged a hose/connection whilst doing your service?

Mick
Title: Re: Poor MPG on 2.5TD
Post by: zirk on 07 December 2009, 14:50:37
As Mick says, plus does it feel like the Turbo's doing its job properly, Maf sensor (if its got one) could cause bad Mpg, spongy power.

Other stuff not so obvious, brakes binding, partailly blooked exhaust.

 :-/
Title: Re: Poor MPG on 2.5TD
Post by: Seth on 07 December 2009, 15:41:09
Quote
Have you checked the obvious like.......diesel leaks around filter seal/collar, leak off pipes and air filter box and connecting hoses/pipes. Have you accidently dislodged a hose/connection whilst doing your service?

Mick

Agreed Mick, but before delving further, I'd fill a new fuel filter with Forte and give it an Italian tune-up!

Also, use 'proper' diesel - avoid the supermarket-type juice.
Title: Re: Poor MPG on 2.5TD
Post by: MickAP on 07 December 2009, 16:34:29
Quote
Quote
Have you checked the obvious like.......diesel leaks around filter seal/collar, leak off pipes and air filter box and connecting hoses/pipes. Have you accidently dislodged a hose/connection whilst doing your service?

Mick

Agreed Mick, but before delving further, I'd fill a new fuel filter with Forte and give it an Italian tune-up!

Also, use 'proper' diesel - avoid the supermarket-type juice.

He's done that with diesel magic. :y
Suppose it won't harm doing it again.
Supermarket fuels, .....err I won't touch Sainsburys smokes like hell :-[ but Asda and Tesco ok especially when they give you a voucher worth 5p off per litre :y

Mick
Title: Re: Poor MPG on 2.5TD
Post by: Essex Pete on 07 December 2009, 17:09:47
It seems to still pull really nice.  maybe a bit slower than it used to but not really a noticable difference.  It doesnt seem to smoke any more than in the past.  I havent had a good look around the bay due to the shite weather, but i will get it in the garage at the weekend when i do the stat. 

The EML when cold problem isnt new, it did that before the service, but then stopped doing it for a while during the summer, either that or i didnt notice it.  Im going to check the connections to the temp sensor for the ecu make sure that isnt causing a problem.  I had the egr off not long ago and cleaned it out, all seemed good.

It doesnt smell of diesel in the bay, or anywhere round the car, so i dont think it is leaking.  I had the leakoff pipes replaced earlier this year as one split.  It reeked of diesel then, so i would notice if it was leaking again.

Occasionally i have filled up at saisburys, but since it has been playing up i have run 3 tanks through it, one esso, one shell and one sainsburys.  All have yielded less than 450 miles to a tank
Title: Re: Poor MPG on 2.5TD
Post by: damage consultant on 07 December 2009, 20:20:01
Your not alone with this fault :-[ my tractor (auto) does exactly the same you lift foot off gas eml light flashes.
I'm also getting around the low 400miles per tank
I had codes 34 injector timing out of range and 64 fuel quantity out off range. I got codes cleared 2 months ago now there back with avengence.
Ive tried whynes fuel treatment had injectors & pump out and tested changed air & fuel filter every 14 days checked the timing the lists endless would be here all night wrighting.
I'm almost totaly bald with frustration not even my local garage will look at it every time they see me coming they s**t a brick and hide. :( :(.
Title: Re: Poor MPG on 2.5TD
Post by: Turk on 07 December 2009, 22:19:06
I get a quick flash of the EML on throttle lift off when cold and have done for months, but I'm getting around 41mpg general town and A roads and around 48mpg if sat at just below 70mph on a run.
Title: Re: Poor MPG on 2.5TD
Post by: Andy H on 07 December 2009, 22:46:41
Quote
Your not alone with this fault :-[ my tractor (auto) does exactly the same you lift foot off gas eml light flashes.
I'm also getting around the low 400miles per tank
I had codes 34 injector timing out of range and 64 fuel quantity out off range. I got codes cleared 2 months ago now there back with avengence.
Ive tried whynes fuel treatment had injectors & pump out and tested changed air & fuel filter every 14 days checked the timing the lists endless would be here all night wrighting.
I'm almost totaly bald with frustration not even my local garage will look at it every time they see me coming they s**t a brick and hide. :( :(.
Is the injector pump driven by the cam chain on the traktor? Could the cam chain have jumped a sprocket and put the injector timing out?
Title: Re: Poor MPG on 2.5TD
Post by: damage consultant on 08 December 2009, 08:07:09
I had a problem some time ago when it shredded the cotter on the fuel pump and the nut fell off so engine stopped. mcallister fuel injection got it going but its never been the same we had a big barney bassicly I called him a usless a-hole that couldn't fix a puncture. yes its chain driven weve had all the front end off( belts and fan) and all the marks line up the only thing left it to replace the chain thats not a job for me.
the chain can be changed without taking the front end off engine to bits specialist job though.
Title: Re: Poor MPG on 2.5TD
Post by: Andy H on 08 December 2009, 09:47:48
I don't know if the sprocket is on a plain shaft or a tapered shaft.

It might be that the cotter has sheared again and the taper is holding the sprocket on but out of alignment (or the keyways and cotter might be damaged and permitting sufficient misalignment to put the timing out).
Title: Re: Poor MPG on 2.5TD
Post by: Seth on 08 December 2009, 16:05:41
Quote
Quote
Your not alone with this fault :-[ my tractor (auto) does exactly the same you lift foot off gas eml light flashes.
I'm also getting around the low 400miles per tank
I had codes 34 injector timing out of range and 64 fuel quantity out off range. I got codes cleared 2 months ago now there back with avengence.
Ive tried whynes fuel treatment had injectors & pump out and tested changed air & fuel filter every 14 days checked the timing the lists endless would be here all night wrighting.
I'm almost totaly bald with frustration not even my local garage will look at it every time they see me coming they s**t a brick and hide. :( :(.
Is the injector pump driven by the cam chain on the traktor? Could the cam chain have jumped a sprocket and put the injector timing out?
There's two chains:
One connects the crankshaft to the pump, the other connects the pump to the camshaft.
Title: Re: Poor MPG on 2.5TD
Post by: damage consultant on 08 December 2009, 18:31:01
As far as i'm aware it a tapered shaft as you say the keyway could be damaged think its time to look on flea-bay for a new pump. :-/
Title: Re: Poor MPG on 2.5TD
Post by: Seth on 08 December 2009, 18:49:37
Quote
As far as i'm aware it a tapered shaft as you say the keyway could be damaged think its time to look on flea-bay for a new pump. :-/

I'll very soon have my previous '98 TD Estate up for sale.
Had a brand-new pump and no.4 injector last year, and it's chipped too!
Title: Re: Poor MPG on 2.5TD
Post by: damage consultant on 08 December 2009, 19:02:34
D.I.V.O.R.C.E was mentioned by my wife if I buy another car ;D ;D
Title: Re: Poor MPG on 2.5TD
Post by: Dodger on 08 December 2009, 20:25:26
Quote
D.I.V.O.R.C.E was mentioned by my wife if I buy another car ;D ;D

So you're desperately looking then!!  ;D ;D ;D
Title: Re: Poor MPG on 2.5TD
Post by: Essex Pete on 09 December 2009, 12:53:14
OK something new for today, it didnt want to start this morning.  Just turned over for ages.  I did 3 or 4 cycles of the glow plugs and still it struggled.  So at the weekend i will also be checking the lifter pump in the tank to make sure that is still connected.  What else do i need to check over? 
Title: Re: Poor MPG on 2.5TD
Post by: MickAP on 09 December 2009, 14:50:56
Re your latest problem, try a squirt of easi start into the air intake, take the hose off the filter box and squirt down the pipe. If it starts and runs ok then maybe this problem on cold start could be glow plugs, who knows, need testing.

BTW easi start not recommended for using on a regular basis, just to get you going.
Title: Re: Poor MPG on 2.5TD
Post by: davo on 09 December 2009, 15:25:29
hi guys, first post, hope i can be some help, i had bother starting my 2.5td, and found the fuel lift pump gauze in the tank, all but blocked with shite,,worth lifting out the pump, cleaning the gauze, and putting an airline through the pump itself, i did that and instant starting,,,i also modified the setup slightly by cutting another hole in the side of the  plastic pump housing, and fitting another piece of gauze as a strainer, so far so good, as for the idle and cutout problem, i have exactly the same fault, it throws up the fault code pointing to the middle injector (timing one) i replaced it with a new one, but same problem, tried crank sensor, still same, chipped the ecu, still same,,all pipes are tight, wiring harness around the sensors all ok, sorta give up,  :-/
Title: Re: Poor MPG on 2.5TD
Post by: damage consultant on 09 December 2009, 20:43:53
AHH easy start is like heroin for diesel engines >:(.
Pete before you go taking the tank pump to bits drop the fuel filter and see if there's diesel in it you don't need to take it completely out and see if its got any fuel in it won't lift the last 1/2inch off fuel.
try topping it up and crack all the injectors then turn over if you get fuel pissing out stop and tighten the nuts the engine should start then tank pump is blocked.
If your only getting lots off white smoke the glow plugs are goosed I tend to use boiling water poured over manifold or a small plumbers blowtorch to heat manifold it only takes a small amount of hot air to get it to fire.
try putting a earth lead to the ecu direct from the battery and also engine to battery.
could have dirty injectors
check all the fuses both in the car and engine bay.
Try bridging out the fuel pump relay or replace it.
If none of the above works the main fuel pump is dead.
Title: Re: Poor MPG on 2.5TD
Post by: Omegatoy on 09 December 2009, 21:24:55
HANG ON GUYS!!!
go back to basics first, you mention that it started right after you did the service? then look at the fuel heater on the filter, bet its slightly loose and letting air in, cure?
remove filter then tighten heater collar where the filter screws up to (it will turn if you move it by hand) only needs to be hand tight then replace filter and try,
now if you know what your doing you dont need to remove the filter but if you havent done it before then you should remove it to see what happenswhen you do a quick job that doesnt work!! once you see it you will never make the same mistake again!!
this is assuming of course that this is the fault!! :y
but it hasnt been mentioned in any of the above post so far! so thought it worth a try
Title: Re: Poor MPG on 2.5TD
Post by: Essex Pete on 09 December 2009, 22:06:30
Ok something new.  The car broke down on the way home tonight.  No fuel getting to the filter.  I guess that points firmly at the lifter pump.  I will be pulling it out tomorrow for a looksie.  Tried bleeding the injectors and filter, but there was nothing being pumped up from the tank.  When ignition is turned on there is no sound from the pump, so either it has completely died from trying to suck agaist a blockage perhaps, or there is an electrical issue.  All will be revealed tomorrow
Title: Re: Poor MPG on 2.5TD
Post by: Essex Pete on 09 December 2009, 22:08:40
Quote
HANG ON GUYS!!!
go back to basics first, you mention that it started right after you did the service? then look at the fuel heater on the filter, bet its slightly loose and letting air in, cure?
remove filter then tighten heater collar where the filter screws up to (it will turn if you move it by hand) only needs to be hand tight then replace filter and try,
now if you know what your doing you dont need to remove the filter but if you havent done it before then you should remove it to see what happenswhen you do a quick job that doesnt work!! once you see it you will never make the same mistake again!!
this is assuming of course that this is the fault!! :y
but it hasnt been mentioned in any of the above post so far! so thought it worth a try

When i changed the filter this collar was very loose and was only a couple of threads from falling off with the filter.  I made sure this was well tight before i fitted the new filter
Title: Re: Poor MPG on 2.5TD
Post by: Seth on 09 December 2009, 22:13:12
Great minds think alike OT!
Just by tightening the fuel heater collar to the filter case cured no end of ills on mine.
Gotta be worth a try.
Title: Re: Poor MPG on 2.5TD
Post by: Essex Pete on 09 December 2009, 22:13:46
Quote
try topping it up and crack all the injectors then turn over if you get fuel pissing out stop and tighten the nuts the engine should start

Thanks for taking the time to write all this!


Firstly me and the AA guy tried this tonight.  the small amount of fuel in the filter is getting to the injectors once bled, but there is no supply to the filter from the tank, so the car starts but only for a second or so

Quote

check all the fuses both in the car and engine bay.
Try bridging out the fuel pump relay or replace it.
If none of the above works the main fuel pump is dead.

I will be doing this tomorrow to see if it is an electrical issue, or whether the pump is dead

Title: Re: Poor MPG on 2.5TD
Post by: Essex Pete on 09 December 2009, 22:16:29
With regards to the problem of cutting when lifting off when cold, i was thinking ill check the coolant sensor and wiring to check that is all ok.  i cant see why it would be anything else as it only does it when cold.  If another sensor was playing up it would be all the time
Title: Re: Poor MPG on 2.5TD
Post by: davo on 11 December 2009, 09:12:42
keep me posted, be keen to find out what the resolution  :-/was ,,,,