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reasons for overfueling


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ok. i suspect after a chat with paul that my car is overfueling a tad.

as its a bit hefty on fuel and still feels down on performance, i couldnt get away from a polo gti the other day.

what else could be a cause of it other than a faulty lamda? + sensors etc?

as i'll hopefully be changing that soon(ish).

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Have you maybe got a vacuum leak from your map sensor or FPR?

Do Glanza's have Coolant temperature sensors? That could lead the car to think it's colder than what it is if faulty and lead to overfuelling? Also I'm sure you replaced the thermostat when you fisrt got the car didn't you mate?

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ok. i suspect after a chat with paul that my car is overfueling a tad.

as its a bit hefty on fuel and still feels down on performance, i couldnt get away from a polo gti the other day.

what else could be a cause of it other than a faulty lamda? + sensors etc?

as i'll hopefully be changing that soon(ish).

Mate run a diagnostic check, See if you get the map sensor error code pop up.

Sounds like youre map sensor is up the wall, making it ovverfuel.

Thats obviously if you havent got any leaks in the vacum lines as lobotomoy said.

But it could also be the temp probe sensor.

Best thing to do is to get it to a rolling road bud.They will diagnose the problem

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wheres the map? checked the fpr the other day... seems fine.

and wheres the temp probe sensor? i didnt do the thermostat when i got it mate... never needed to.

just do a normal diagnosic check? bridging the two ports in the diagnostics box?

ive been meaning to get it rolling roaded for months, but just havent had the money or time... maybe i'll organise one, dont know of any round my area!

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lol, map sensor up the wall ;\

you lot make me laugh sometimes ^^/

for overfueling, lets start at the basics. have to checked your thermostat? if you havnt checked it then do that first. this is a notorious problem in starlets for overfueling. even if its been changed, check to see if its ok.

also, what boost are you running and what pressure are you at on the fpr (if it is aftermarket that is). it should be about 30-33psi on idle.

if these are ok, then come back and well have another think.

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His car is pretty much standard Rick -- and I was pretty sure he had changed the thermostat when he bought the car too. So we moved on to other suggestions. If the fpr is ok then there's not too much else apart from leaky injectors or the map sensor surely?

Hey rich, does you temp needle sit fine in the middle once it's warm? Mine dropped when I was driving fast, oddly, and never sat at halfway. That was my signs for a new thermostat.

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im pretty stock at the mo.

no aftermarket fpr, just exhaust system, bov, and smashed out cat running .8 bar

not had the thermostat done yet, as i hadnt noticed it taking ages to come up to temperature.

the needle sits just a tiny bit below half way even when driving at high speed.

ive ran it up checked the bottom hose and its cold and the top hose is hot... left it for a little while longer and the bottom hose is warm, so surely the thermostat is ok?

things to test and check would be great as im loosing patience with it at the moment.

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tyres are checked once a week generally. no extra weight.

its had new:

dizzy

plugs

rotor arm

fuel filter

airfilter

oil & filter

new front discs & pads

checked all the gaskets and pipes off the turbo including vacum lines and there seems to be no boost leak.

my main issue is the performance... i know ive been bitching about it being under power for ages, but i should have surely destroyed that polo gti the other day?

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if your map was fuggered, it would either not be reading enough boost and youd be running lean. or it would be stuck open and youd be overfueling something silly, im talknig 80 miles to a tank silly.

with a smashed cat, youd be popping flames everywhere.

i dont think its injectors because they tent to either stick open or closed. so youd be either mega fueling or no fuel. so i doubt its that. the car would run shit as well.

so unless it is that extreme id look elsewhere.

seriously, change your thermo, itll take you half ano hour and cost 12 quid.

have you reset the ecu? they can work them selves up into a bit of a fuel loving mood sometimes due to the mild learning ability they have. give it a reset, and see what happens then.

appart from the overfueling, is the car running any differently?

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i have reset the ecu only last month.

might have to give the thermo a try.

tempted to save up a bit and take it to dave burwash if the thermostat doesnt work...

i think it was a 2000 reg so about 115bhp polo.

the only way i can describe how it feels is:

it ticks over perfect... at about 800-900rpm and i boot it i get the turbo kick in and theres a gobfull of torque (probably not as much as everyone else) and it pulls but it kinda feels faster than it actually is...

it feels like its running on three but without the poor idling if you know what i mean? it runs out of power just after 6k.

im getting no boost spiking either.

the reason i think its not running right is that ive been in a few other glanzas (and actually driven another one) that were standard and they felt miles faster; more pull, wheel spinning everywhere even in second.

i get wheelspin out of first but not in second and i have 14's.

plus i cant really pull away from my old n/a that well while accelerating im pulling away a tiny bit but no where near as much as i expected.

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If the diagnostic came back clear, I'd check youre thermostat first.

Sorry to VTRick , i thought rich had allready replaced one.My mistake.

That could well be why its overfuelling, so replace that and see how it feels then.

But tbh rich, i wouldnt worry just by comparing youre V to others you have driven, they may have different condition engines etc.

So many variables that make an engine of the same type feel completely different.

I'd suggest getting the thermostat replaced, and if its no different, take a trip to youre nearest rollers to have the fuelling checked.

It could just be that youre getting used to the power it produces.

when i bought mine bog standard , it felt amazingly quick, but after a few days it soon faded away :lol:

Standard starlets wont pull very much higher up than 6k any way bud.The ct9's run out of puff and become superheated hair dryers :rolleyes:

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I only bypassed my LO boost solenoid for 2 weeks and the car felt like a different animal but I got wheelspin all the time and fuel cut a few times so I changed it back after which the car just felt shit and slow, especially in 1st and 2nd!! Made me feel like there was something wrong, but there wasn't.

I just found to get any go out my Glanza I'd have to give it loads of revs from 1st gear all the way, say I was in 3rd and just put my foot down, it would take ages to get anywhere.

Best option would be to take it to a rolling road to check the fuelling, or if there's anyone in the area with a wideband AF gauge, it wouldn't take long to set up and would belay any fears you've got.

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2000 polo gti's aint slow in any case and there 125hp standard. if it sounded rather grunty then its got an induction kit which they respond well to (132hp my mates one)

anyway back to your car, check fr any leaks at the bottom of the cat after it was gutted as this makes your car uber slow (i found that out the hard way) and makes it sound rough.

also if u aren't running any other mods, i'd bypass the LO boost solenoid :rolleyes:

i think mines is overfueling aswell tho lol, after my glanza's bn allowed to 'stretch its legs' i get a nice big wiff o optimax lol, not too bothered about it cause it means that my pistons aint gonna turn into jelly lol

hope this helps !!!

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ok guys, i had my spark plugs out today to see if there was any problems with the new plugs... it turns out that number 2 lead was covered in what appeared to be rust residue? pic below:

DSC00086.jpg

the plug outa number 2 was covered in crap all in the washer and all down the thread too??

DSC00080.jpg

DSC00081.jpg

the others seem to be ok... just thought i'd post pics of how the plugs looked.

i drenched the lead stems in maintenance spray (de watering fluid) and she did seem to idle a bit better... and when revved up it sounded alot less 'missfirey' is all i can describe it as... definitely felt alot more resonsive to drive too.

DSC00085.jpg

DSC00083.jpg

DSC00082.jpg

DSC00078.jpg

the only other thing i noticed was that around the bottom of the ceramic part of the plugs (just above the hex) there seemed to be burn marks? only about 4mm long going up towards the top, but they went all the way round! + number 2's were far worse. i meant to get a photo but didnt get time.

could this be another side to the problem? is it likely that the leads are shot? and can you get a new set for less than £50? as toyta quoted me £70

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no mate you misunderstand... the ceramic stem was burnt! i.e the bit that the lead clips over!

no didnt bother with the gaps.

but ive gotta admit now she feels much more lively. pulls hard and clean now... only thing im noticing now is that it feels like at higher revs its holding back (feels a bit like when you get near to fuel cut) but im only at .75-.8 bar.

im assuming that its because the leads are buggered.

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no mate you misunderstand... the ceramic stem was burnt! i.e the bit that the lead clips over!

no didnt bother with the gaps.

but ive gotta admit now she feels much more lively. pulls hard and clean now... only thing im noticing now is that it feels like at higher revs its holding back (feels a bit like when you get near to fuel cut) but im only at .75-.8 bar.

im assuming that its because the leads are buggered.

Oh righty.Sorry yeah i misread Rich :p

If the leads are damaged, then yeah, it may feel a bit shite at higher rpms.Youre not going to be getting enough current through the lead to create the sparks bud.

Whack some newones on and she should be fine.

Glad its feeling better finally though bud

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