MAF sensor on a 1.8 CFi (C18NZ) ??

[phalinmegob]

yes please as this something i may have to tackle quite soon on my c18nz lump and i am absolutely useless with cars but cant afford garage costs.

[Envoy CDX]

p.s,...I also took photo's of my Cam Belt check / change procedure.

Would you like me to reproduce this as a "How 2 - Change the Cam Belt on a C18NZ engine."

Regarding the ron plug, I have seen a few variations with the numbers 91 (?), 95 (Unleaded) and 98 (Super unleaded and leaded 4*).

Mine has 95, and 98 on the flip-side.

Great news there, hopefullly that'll sort everything out for you
As for the How2, can never have too many so it will be a welcome addition

As for the ron plug, if you want to try another one just incase, bang your address in a PM and I'll send one down to you

[Robsey]

As for the How2, can never have too many so it will be a welcome addition

It is really straight forward, the tip with linking the 13mm spanner onto the 15mm spanner for the multi-v belt tensioner worked a treat...I still have all the skin on my knuckles!!

I'll gather all my pictures and put up a thread in the next few hours!!

As for the ron plug, if you want to try another one just incase, bang your address in a PM and I'll send one down to you

I'll send you a PM in the next couple of days...no rush, I've only been tatting about with this since November...lol

The fix today is only a short term solution...cleaning everything up of soot etc, is something I have to do every month or so, or else the car won't start...mainly due to the amount of soot on the plugs, shorting out the tips.

[Envoy CDX]

As for the How2, can never have too many so it will be a welcome addition

It is really straight forward, the tip with linking the 13mm spanner onto the 15mm spanner for the multi-v belt tensioner worked a treat...I still have all the skin on my knuckles!!

I'll gather all my pictures and put up a thread in the next few hours!!

As for the ron plug, if you want to try another one just incase, bang your address in a PM and I'll send one down to you

I'll send you a PM in the next couple of days...no rush, I've only been tatting about with this since November...lol

The fix today is only a short term solution...cleaning everything up of soot etc, is something I have to do every month or so, or else the car won't start...mainly due to the amount of soot on the plugs, shorting out the tips.

Handy tips are good to share If it's sooting up, it sounds like overfueling, so I'd look at the lamda - theres a 1.8LS in the breakers if the lamdas there I'll pick it up
I have a RON plug sitting here with your name on it, so as and when

[Robsey]

Handy tips are good to share If it's sooting up, it sounds like overfueling, so I'd look at the lamda - theres a 1.8LS in the breakers if the lamdas there I'll pick it up
I have a RON plug sitting here with your name on it, so as and when

Thanks, that would be great...the reason why I shyed away from the Lambda, is because it was changed for my MOT in November 2008, and I expected it to last more than 18 months...the first one lasted for 13 or so years lol.

Also the AA patrol said that he felt it was the CTS...

The fault code that flashes up, (44) refers to Lambda Sensor - Mixture Lean (weak).

[Envoy CDX]

Handy tips are good to share If it's sooting up, it sounds like overfueling, so I'd look at the lamda - theres a 1.8LS in the breakers if the lamdas there I'll pick it up
I have a RON plug sitting here with your name on it, so as and when

Thanks, that would be great...the reason why I shyed away from the Lambda, is because it was changed for my MOT in November 2008, and I expected it to last more than 18 months...the first one lasted for 13 or so years lol.

Also the AA patrol said that he felt it was the CTS...

The fault code that flashes up, (44) refers to Lambda Sensor - Mixture Lean (weak).

CTS is about £9 on trade, £13 over the counter retail from Vauxhall if you haven't already changed it - it can play funny buggers with the ECU for under and overfueling depending on how it fails.
Sometimes they appear on eBay for £5 (genuine ones too, I stay clear after the aftermarket varient after having 2 fail in a matter of months last year).

[Robsey]

I agree,
I only get original Bosch / Valeo / Delco parts for the cav ignition system, as non oem parts do seem to fail quite quickly.

I get paid at the end of the month, will get a CTS then.

[Envoy CDX]

I agree,
I only get original Bosch / Valeo / Delco parts for the cav ignition system, as non oem parts do seem to fail quite quickly.

I get paid at the end of the month, will get a CTS then.

[Robsey]

Well I fitted a new CTS, whilst still parked up at Lookers Vauxhall in Ellesmere Port.
The guy was very helpful, and was suprised that I wanted a CTS.
He said that it was unlikely that they would have one, but he would have a look inthe back anyway.
I was in luck obviously...there was one on the shelf that had been ordered back in January

When driving back, I was still getting the EML every now and again..not checked the code, but I know it will be 44.

The fuel economy was very slightly better, but I still only did about 110 miles on £26 worth of petrol...

Now about 28 mpg, rather than the old 25.6 mpg that I got last week on the motorway to/from Ellesmere Port.

Suppose the next step is to clean and re-seat or replace the Oxy sensor.

[Envoy CDX]

Well I fitted a new CTS, whilst still parked up at Lookers Vauxhall in Ellesmere Port.
The guy was very helpful, and was suprised that I wanted a CTS.
He said that it was unlikely that they would have one, but he would have a look inthe back anyway.
I was in luck obviously...there was one on the shelf that had been ordered back in January

When driving back, I was still getting the EML every now and again..not checked the code, but I know it will be 44.

The fuel economy was very slightly better, but I still only did about 110 miles on £26 worth of petrol...

Now about 28 mpg, rather than the old 25.6 mpg that I got last week on the motorway to/from Ellesmere Port.

Suppose the next step is to clean and re-seat or replace the Oxy sensor.

Well, it's one less thing to consider, and it wasn't a total waste of money the ECU doesn't always update right away though

[Robsey]

Well, it's one less thing to consider, and it wasn't a total waste of money the ECU doesn't always update right away though

I plan to get my little "dremmel" type tool out tomorrow, and clean the outer shoulders of the oxy sensor, I will then fit a wrap-around steel clamp (called a Haden Clamp) around the shoulders, and attach a fresh earth link wire to a grounding point either on the engine or the bodywork.

This will identify if the fault is caused by a corroded thread where the sensor screws into the down-pipe.
The sensor is really tight at the moment, so will only swing on it as a last resort, to remove and / or clean it.

This is a haden clamp.

haden clip.JPG (3.16 KiB) Viewed 703 times

[Envoy CDX]

Well, it's one less thing to consider, and it wasn't a total waste of money the ECU doesn't always update right away though

I plan to get my little "dremmel" type tool out tomorrow, and clean the outer shoulders of the oxy sensor, I will then fit a wrap-around steel clamp (called a Haden Clamp) around the shoulders, and attach a fresh earth link wire to a grounding point either on the engine or the bodywork.

This will identify if the fault is caused by a corroded thread where the sensor screws into the down-pipe.
The sensor is really tight at the moment, so will only swing on it as a last resort, to remove and / or clean it.

This is a haden clamp.

haden clip.JPG

I would look at cleaning it up first before adding extra wires. See if that helps. 20mm spanner you'll need I beleive.

[Robsey]

Yeah it's a really odd sized hexagon on the sensor.

Was thinking I would rule out "excessive" resistance between the sensor body and the down pipe, as this would have the same effect as having a lean mixture.

That is "reduced voltage across the sensor"

Higher resistance = lower voltage across the sensor
Lower voltage = weaker mixture (as perceived by the ECU).

[Envoy CDX]

Yeah it's a really odd sized hexagon on the sensor.

Was thinking I would rule out "excessive" resistance between the sensor body and the down pipe, as this would have the same effect as having a lean mixture.

That is "reduced voltage across the sensor"

Higher resistance = lower voltage across the sensor
Lower voltage = weaker mixture (as perceived by the ECU).

Hope it works out for you

[Robsey]

Well I got the 22mm Combination spanner out today, this seemed to fit the O2 (lambda) sensor perfectly, athough there ain't much space to swing such a large spanner.

I took the sensor out to give it a good clean. I'm a bit puzzled though, because when I was shaking out some of the soot from the tip, I could distinctly hear something rattling about inside.

I don't know whether I should hear something or not.

Here is my sensor before cleaning...

o2sens2.jpg (46.1 KiB) Viewed 689 times

I took the car for a spin afterwards, but that darn EML came back on again!!

So before leaving work this evenng I thought that would check my inlet manifold and exhaust manifold again.

One of the torx socket screws, which hold the top of the throttle body onto the lower part, was loose. So I tightened this up.

My attention turned to the exhaust manifold, where I thought that I would check how tight the nuts were.
The bottom nut adjacent to plug No.4 appeared to be quite mobile, so I decided to tighten it, however it did not seem to tighten at all.

I was only using a standard 13mm combi spanner, so was not swinging on it, when......

Oh no, the nut and half of the stud sheared off...aaaaarghhhh!!!

I will now have to drill out and extract the remnants of the stud.

When I got home, I had a look at the stud, and it had a very tiny patch of shiny metal on the edge of the thread...the rest was quite dull, and so the stud must have been partially fractured for some time, until I decided to tighten it today.

stud2hl.JPG (18.88 KiB) Viewed 689 times

[Envoy CDX]

Ouch, might explain a couple of things. hopefully it's a nice easy fix

[Robsey]

If I use an 8mm or 8.5mm drill to do a pilot, I can then get the hole in the centre of the stud.

Then I can drill a small diameter hole for a torx driver to be tapped into...hopefully the splines will bite into the stud remnants and allow me to back the stud out

Someone will say that I should use an Easy-Out, but these are too hard and brittle...they usually snap when you're giving it some umph to get the stud out.

Failing that, it is a matter of drilling the hole and tapping a fresh thread...
I am glad I have been an engineer for 25 yrs. (straight from school, just before the first world war...) lol

Like you say, should be a simple fix....as long as I don't drill too deep.

For better access, I will need to remove my radiator, fan and front grill.

Bit of a pain, but quite do-able.

Any ideas about the rattleing O2 sensor?

Regarding an air leak on the exhaust manifold...would that draw air in and thus weaken the exhaust gas???,
OR
I am sure if anything it would just chuff out through the seam of the gasket, and as such have no effect on the weakness / richness of the mixture.

[Envoy CDX]

If the gasket has had it, then it will probably effect things, however I'd go to vauxhall, buy a new stud and use that as a guide on how far to drill (you'll need the stud anyhow to replace the snapped one).

I' pretty sure the lamda shouldn't rattle, but I've never really had much experience with them so can't say hand on heart.

Since your removing the radiator, it would be a good time for a full coolant flush too

[toptune]

robsey looks like from your o 2 sensor your engine is running rich should be some where about brick red in colour,
a o 2 sensor should not rattle when you shake them,
are you still running soot on plugs 1,2,3?

when i took my o 2 sensor out it was brick red
should not really need to clean the o 2 sensor

[Robsey]

Since your removing the radiator, it would be a good time for a full coolant flush too

I had a split in my top hose at the rear of my cylinder head until I fixed it in November last year.

I think I was continually changing / topping up the coolant for approx 2 months prior to then.
Topping up about 2 litres of fresh mix, every other day

I also changed the water pump in November, and so had a total flush and coolant change then.

If I was being pedantic, I could just take the head off the engine, and then replace ALL the gaskets on reassembly...that would rule out any further gasket leaks.

[toptune]

Sorry that I am dragging my heels on this one...can't even blame the weather..

Just mega-busy either working between Manchester and Ellesmere Port, or simply looking after my (very dependent) wife.

But I am keeping an eye on the ideas so far.

Must admit, I was unaware that the Ron plug could fail...
Yet another one to check through

My list so far

1) Air leaks into induction and exhaust sytem - done...nothing found
1b) Replace split exhaust back box - done...no change
2) MAP sensor on bulk-head - done...slight change in symptoms
3) Check for fuelling problem - starvation etc - done...better starting after replacing corroded fuel pipe
3b) Tried replacement injector - done - no change

4) Check timing ...timing belt and marks - to do
5) Check Coolant Temp sensor as advised by AA guy - to do
6) O2 Sensor due to 44 EML code - O2 sensor lean mixture - to do
7) RON plug ...try donor plug - to do

Honest, I will report back...when I get chance to do them

6) how can it be lean when the o 2 sensor is black and sooty?
have you tried changing the ron plug or is the ecu faulty
have you checked for any other fault codes on the ecu?
is the rest of the exhaust system gas tight? i know you broke a exhaust stud but apart from that,
is the vacuum pipe that goes from inlet manifold to map sensor ok?
is the air filter clean?

[Envoy CDX]

Since your removing the radiator, it would be a good time for a full coolant flush too

I had a split in my top hose at the rear of my cylinder head until I fixed it in November last year.

I think I was continually changing / topping up the coolant for approx 2 months prior to then.
Topping up about 2 litres of fresh mix, every other day

I also changed the water pump in November, and so had a total flush and coolant change then.

If I was being pedantic, I could just take the head off the engine, and then replace ALL the gaskets on reassembly...that would rule out any further gasket leaks.

Be pedantic do the job Gary style - it's what I did last weekend Head off, new gaskets, cleaned the lifters, replace the followers, cam and thrust pads. New timing belt.

[toptune]

As for the How2, can never have too many so it will be a welcome addition

It is really straight forward, the tip with linking the 13mm spanner onto the 15mm spanner for the multi-v belt tensioner worked a treat...I still have all the skin on my knuckles!!

I'll gather all my pictures and put up a thread in the next few hours!!

As for the ron plug, if you want to try another one just incase, bang your address in a PM and I'll send one down to you

I'll send you a PM in the next couple of days...no rush, I've only been tatting about with this since November...lol

The fix today is only a short term solution...cleaning everything up of soot etc, is something I have to do every month or so, or else the car won't start...mainly due to the amount of soot on the plugs, shorting out the tips.

soot on plugs, o 2 sensor,inside exhaust headers means the engine is running rich, this can knacker the cat converter
should not need to clean the plugs every month,
plug colour should be dark grey/light tan/ brick red and russet brown at the max = dark grey leaner/russet brown richer and black and sooty to rich

[Robsey]

Running rich has been the problem all along...

All four plugs get heavily sooted up to the point that eventually the plugs cannot pass a spark.

I get an EML flash code 44 = Lambda Sensor - Mixture Weak.
No other codes.
However the exhaust smells "Rich".

I have changed / replaced: -
The MAP sensor,
CTS (Colant Temp Sensor)
Spark Plugs (two-electrode type)
Thermostat
Exhaust back box
Gauze filter in the cam-cover

Checked: -
Timing belt / timing
HT Leads
Coil LT Connections
Checked all vacuum hoses
Visually checked gaskets for leaks, and sprayed plus gas and listened for change in engine note.

Cleaned: -
Dizzy Cap and Rotor
Lambda sensor - very black - thick coating of soot.
Breather pipes

Note - engine is very high mileage, but doesn't smoke (216,460 miles)

All I haven't done is completely replace the head gasket set, and to clean / blank-off the EGR valve.

[toptune]

is it still on the original ecu?
had three ecu's go down on my car first time chucked out black smoke had a job to drive it back,
can not remember what happened the second time but 3rd time kept getting code 35 so changed all sensors still got same fault code then changed ecu and no more code,
then had running rich on plugs 1/2/3 but number 4 ok and o 2 sensor brick red changed ron plug no more problems yet