High Fuel Conumption: Something Wrong Here??

[jnb1]

Since having my zetec, I put 1 tank of fuel in it on the day of purchase (costing £41), and have driven it reasonably well, with the ocassional bit of hard driving for fun. To cut a long story short, the petrol light has come on today at 240 miles, which to me seems pretty poor, considering I have been reading posts of others getting 300+.

I sent the car back to the garage on the 2nd day of purchase because the ACE fail message came on, but this turned out to be a blip, as the car drove fine and was tested on the diagnostics, and needless to say the error hasn't appeared since. However, could someone pleae shed some light on this, as my MPG here seems really poor, especially since my older car (51 plate Proton Wira 1.5) used to average 280-300 per tank).....

Hope someone can answer this

Josh

[Lloyday]

Zetec engines have got a habit of guzzling fuel. The tolerance for a Mk5 1.25 MPG is anywhere between 25-45mpg so you can see why the garage didn't worry so much about this, Taking into account that its a 1.4 and your driving decently then as long as its between that margin ford won't do anything about it, It seems that even though you have a larger engine, I have a larger tank as it costs £50 (regular unleaded) to fill mine up. Best thing I've done is use Unleaded 99 or tesco "momentum", Even though your getting less fuel for the price your paying. A full tank of momentum will probably take me near 100 miles further than a full tank of regular. But I always fill up by £40 and I always get 300 miles out of a tank of super rather than 240 out of regular. It sees me through the week even when I rag the balls off it, Or if your still sceptical try momentum every 3rd tank you fill up.

Hope this answered some questions for you

[james_60]

My 1974 mg midget 1275 gets 28mpg lol and it has a 32 litre tank

Jamie

[jnb1]

Cheers for the info guys :). One other question. Today I was in Halfords and the bloke looked under my bonnet at the air intake pipe, and said that its interesting that there is only a gap on the left for the cold air to be let in (there is a plastic shroud at the end of the air intake pipe with a gap in the left of it. He stated that if this was his car, he would cut the plastic shroud back a bit, so cold air can enter from the front also.

Now, I was a bit dubious about this, as I'm aware of alternated air flow messing up the MAF sensor etc, but I had a word with a mate of mine, and he said he could see no issues in doing it. So eventually after much indecision, I decided to cut the plastic shroud back, esentially allowing air to enter from the front and not just from the left. I have driven the car 60 miles, and there have been no warnings or loss of power (engine seems a tad nippier and sounds slighter nicer), and the MPG has been great. I'm also picking up my replacement BMC filter fillament to drop into my airbox on monday :)

All I want to know is, Have I done something extremely silly here?

[Lloyday]

Not at all, the air shroud in front of your air filter intake is a simple manual adjustment for the amount of air going into your intake, Take it off, maximising the amount of air going into the intake = a lot more power, providing you don't floor it every chance you get then all is well, you should have noticed that you could slide it backwards and forwards, Probably what was happening was that the ECU didn't detect enough air in the engine and tried to get more in but injected more fuel at the same time meaning a lower MPG, should be fine from now on, I'll try the same on mine and see if it improves it :) might have a good tip on your hands there

[jnb1]

Thanks for putting my mind at rest :). If your going to do it, dont chop the shroud back until its completely level with the air intake hole, as you want a small bit over hanging, then round it off with a file so it looks all nice and neat. I looked into simpy unscrewing the shroud, but since it is actually part of the intake pipe plastic, its not really possible. Only issue with this mod, is that if there WAS a problem, you can't re-attach the shroud as you have chopped it off. However, (touch wood), there are no problems :). The torque increase is quite nice, and I cant wait to drop in my BMC filter on monday to see what it adds!

[Lloyday]

Yeah, I'm lacking a bit of torque in first unless I completely floor it, I'd say the only worry is getting muck and dirt into the air filter, but unless its properly clogged then shouldn't be a problem, just thought that you get some fine mesh and just cover the intake to stop big chunks getting in, How much was the BMC by the way?? and any idea on its performance in comparison to a K&N?

[jnb1]

Only problem I can see with adding mesh to the intake is that you would have to be cautious as to what you use for material. To be honest, has the air is pulled up through your front grill anyway, I wouldn't be concerned. You also have your air filter as a second line of defence. The BMC filter in my experience gives you slightly better throttle response than the K&N, although you would be hard pushed to notice most of the time. However, the BMC doesn't need oiling unlike the K&N, although this means that you will need to hoover your filter a bit more often, possibly every 10k miles, perhaps less.

When you cut the shroud off, just leave a small bit overhanging so its not cut completely level, this just makes it look a bit neater if you then file it off and smooth the corners. Just use a fine toothed hacksaw and go slow, you should be fine :). The BMC filter was £43 btw.

[jnb1]

For reference, here are some photos: before and after. The before photo is from google.

[Lloyday]

I can see what you mean by keeping it neat, If that's a sound muffler in your intake then taking that out will give a little boost too, I didn't realise you had to oil the K&N, BMC sounds like hassle free maintenance which I like, I'll post a picture of mine once I get round to doing it. Wait 'til my days off

[jnb1]

One aspect I'm slightly unsure of. If you look into my air intake, you can see two bits of plastic which from triangles at the sides. What are they?

[james_60]

Inside the airbox there is another baffle which is fully removable

Remove that as well and you will notice better throttle responce

Jamie

[jnb1]

@Jamie: Where abouts is this baffle? I will be dropping in my BMC filter tomorrow morning, so I might as well do it whilst I'm in there. Only thing that concerns me, is that if I remove the baffle in the airbox and allow too much air in, is the MAF going to play up?

[james_60]

Take the two pieces apart as if you are going to change the air filter.

I will draw a small picture

next post will be the picture. imagine the air filter box with its top removed (or bottom)

The baffle is like a up and down up and down baffle it quietens the air and loses you power

By keeping the factory box it will have enough hot/cold air.

Jamie

[jnb1]

Cheers for the info Jamie. Can I simply remove it with a screwdriver, or will I have to cut it out?

[james_60]

screwdriver will work but mind your hands

What kind of image files will this forum allow !!!

[Lloyday]

Yeah that was the thing I was talking about, as long as your ECU isn't overworked then you won't get any Errors, it simply slides out, after unbolting like 2 bolts at the front, no need to cut it out, well as far as I know.

[Lloyday]

So many simple modifications, for such a big impression on the power.

[james_60]

dont you take all the credit lloyd !!

Jamie

[Lloyday]

James, draw a picture then upload to www.tinypic.com, then post the URL link here.

[james_60]

Having thought about it you are not talking about the same baffle

Jamie

[jnb1]

@Jamie: I think its .jpg and .png.

@Lloyday: I'm just hoping I can find the screws to loosen for the baffle! :P. If you remove the front baffle also, it should add a bit extra! Also, what classes as "overworking" your ECU? I don't want my ECU to screw up every time I put power on......

In regards to getting the plastic engine cover off, I assume its a 10 mil spanner I need?

EDIT: should I remove the airbox baffle if I have already removed the one at the intake then? I'm just concerned about MAF errors....

[Lloyday]

The baffle you can see in the air intake on the picture?, I can't remember how to take one out so don't quote me on that, It'd take a lot to fry the ECU and actually thinking about it, it wouldn't matter. Ignore that as you don't have turbo's or anything like that, Intercoolers, Induction kits etc.

@josh I think a ratchet and socket would be better for the engine cover, make sure its tight once your done too but don't over do it. As for your baffle, you took off the shroud, the baffle is the bit inside the air intake itself, if you get MAF errors put it back, no worries. If no worries then that's a win too

[james_60]

grrr can i email it to you jnb

[jnb1]

I've already removed the baffle at the front of the air intake pipe, and so far so good. As long as my MAF sensor doesn't go and cry, I'll remove the baffle from inside the airbox too. However, I heard somewhere that de-baffling your airbox actually hurts performace, although I can't find any dyno's to prove this.....

@Jamie@ Sure :)