Problems in Perv land already!!

[londondan86]

Well this is my first post in the wrong fuel section!

The cabby I bought the other day has developed a few issues....

When accelerating it jerks and struggles almost like a massive flat spot unless you are foot hard down when it goes like stink. At first I thought I was running out of juice but just filled up half a tank and its still doing it. It idles completely fine and smooth.

My thoughts are possibly the tps or just in need of a good full service, or running low on juice has dragged crap through causing restriction on part throttle.

I'm a complete perv noob so feel free to ask questions that may come to a resolution sooner.

2.0 16v xsi engine on 77k btw

Many thanks!!

[ginge191]

Scrap it, fit an XUD. Done.

[John1.4]

lambda sensor sounds like, as it adjusts fuelling and is disregarded at WOT

[jammapic]

Lambda or TPS mate

[londondan86]

Scrap it, fit an XUD. Done.

Lol, good constructive advice there chap!!!!

lambda sensor sounds like, as it adjusts fuelling and is disregarded at WOT

Righto, cheers matey. I'll get one from the factors tomorrow and go from there I suppose. What does "WOT" stand for chap?

[samass]

Check fuel filter too

[Scott]

Scrap it, fit an XUD. Done.

Lol, good constructive advice there chap!!!!

lambda sensor sounds like, as it adjusts fuelling and is disregarded at WOT

Righto, cheers matey. I'll get one from the factors tomorrow and go from there I suppose. What does "WOT" stand for chap?

Wide open throttle

[londondan86]

Check fuel filter too

I think I'll be giving it a full service at the weekend anyway so thats on the list, cheers matey

Wide open throttle

The throttle is only wide open when I have my foot buried on the noise pedal isnt it? Or are you winding me up? lol Baring in mind the last petrol I worked on was a carbed 1.4 clio!!!

On a side note, what spark plugs do people recommend, as cheap as poss but will last as long as poss!!!!

---

Bloody hell lamda sensors are £60-70 on ebay!! Down the breakers instead I think!!

[jammapic]

Used ones are normally knackered boss.

Get a Bosch one, get it fitted, clean the throttle pot and it'll be right

The ecu doesn't read lambda when you've got your foot hard in the sharpie, it reads throttle position at 100% and fuels accordingly.

JP

[Niall]

Used ones are normally knackered boss.

Get a Bosch one, get it fitted, clean the throttle pot and it'll be right

The ecu doesn't read lambda when you've got your foot hard in the sharpie, it reads throttle position at 100% and fuels accordingly.

JP

Pretty much this

Also, that whole thing about sucking crap through is a myth just FYI. The pump takes the fuel from the bottom of the tank regardless of how much fuel is in there.

[londondan86]

Righto, new one it is then. Just seems like an expensive punt on a car that only cost 500 quid! Is there anyway of testing the o2 sensor before I take the plunge?

@Nial I see what you mean about the tank but surely any crap which is at the bottom will just sit there undisturbed when the tank has plenty of fuel then when the tank gets low it drags it through, a bit like pebbles on a beach when the tied goes out if you see what I mean!!

[Niall]

Yeah you can test the lambda. There is a guide to sensor testing in the guides section. Its a bit of a difficult one to test though because you need to put the sensor through its whole range to see if it can go through its whole range or not!

Doesnt work like that mate. DOnt forget, a 306 doesnt have a baffled tank so the fuel is constantly being mixed up. Unless something actually sticks to the bottom of the tank (in which case it wont get sucked up), it will get pulled into the strainer in the tank and if it makes it through that, it will get picked up by the fuel filter.

[Toms306]

You can test it with a multimeter. You'll need the correct figures from autodata though. Lambda faults usually bring on the EML though, I had one fail on 2 of the 1.4s!

[Niall]

You can test it with a multimeter. You'll need the correct figures from autodata though. Lambda faults usually bring on the EML though, I had one fail on 2 of the 1.4s!

It rarely brings on the EML. Only in extreme cases.
the majority of petrol cars of that era have a range of 0.4v - 0.8v but some (including the gti6) have a different range. 6 range is 0.2v-0.8v iirc

[Toms306]

Mine must've been extreme then. It wasn't the sensor itself that failed though, it was the heater element in the sensor, both times, both silver top 1.4 TUs.

[Niall]

yeah my old gti was running like a sack of shit before i replaced the sensor and that didnt even bring up a silent code although when i checked the output, the voltage was static regardless of what i did with the throttle lol

[Toms306]

Ah ok, fair enough then! Must depend on how they fail I guess.

Was useful I was at college at the time, just used their Snap-On Solus and it brought up the code 'O2 sensor heater fault' straight away lol. Checked the continuity with a multimeter to prove it afterwards.

[londondan86]

Well I may just get one to go with the service at the weekend. Any plug recommendations? Should I bother with HT leads?

Also I'm planning to wash the engine down as the previous owner got it stuck in a field with her horses meaning there's mud all up the back of the engine. Any tips and no nos? I'm guessing cover everything electrical and leave engine running for a start

[Toms306]

I've jet washed loads of engines without problems so far lol, both petrol and diesel, just as you say really, avoid the intake, get it hot and keep running and just avoid directly spraying electrical plugs. Way I look at it is it all gets wet when you splash through puddles anyway lol.

[adamm306]

why do people say leave the engine running? surely spraying cold water on a hot block would cause warping/cracking damange? ive always sprayed engines with engine degreaser then pressure washed it off cold and repeat if nessarcary

[Toms306]

Keep it hot means the water evaporates rather than working its way down into plugs or rusting things etc.

Again, I'll use the puddle scenario....puddles are cold when they splash all over the block and does no harm lol.

[adamm306]

puddles arent pressurised and sprayed directly at a hot engine block

[Toms306]

Depends how fast you hit them tbh, they're pressured enough to rip arch liners out.

Blocks are pretty thick/solid anyway, I've never heard of anyone damaging one with a jetwash.

[adamm306]

Depends how fast you hit them tbh, they're pressured enough to rip arch liners out.

Blocks are pretty thick/solid anyway, I've never heard of anyone damaging one with a jetwash.

heh fair enough but you always hear horror stories with things like this so i never risk it knowing my luck id end up cracking a block!

[Toms306]

Good point, but you're risking water getting into the electrics or rusting bolts by doing it cold. Would worry about it either way lol.

[adamm306]

not much eleccy on a XUD though

and besides id rather have a rusty bolt or two than a fubar'd engine (extreme scenario lol)