Spark Plugs

[CapStick]

Trying to track down a problem on the lads 1.0 corsa
the three pot twelve valve petrol version T Plate

Done all the things bought up by the Diagnostic

New idle air valve
New egr valve
Everything else seems to work fine nothing showing up on Diagnostic

Fuel pump seems to be working ok , fuel side of things looks good.

New cat and manifold so exhaust looks good.

However car starts to slow and revs cutback at about 50 mph moreso up hill

engine light shows when this occurs and goes out if /declutch clutch or drop revs a bit.

If revs kept constant , vehicle pulls uphill fine.

70 thou on clock

Now clutching at straws.

So 1 question
He changed plugs to these four pronged
pre factory set jobs
anyone had any bad experiences using these.

any other info gratefully recieved.

If you saw something similar posted a couple of months ago its still same problem.
BTIA

 

[Mike (2)]

i was going to say
there was a long threads on this a while back!
thought it was sorted!

how about as a test, put the old sparkies back in?

not got a dicky accelerator potentiometer has it?
(if it's the type with one fitted)

mike

 

[malcolm]

Trying to track down a problem on the lads 1.0 corsa
the three pot twelve valve petrol version T Plate

Done all the things bought up by the Diagnostic

New idle air valve
New egr valve
Everything else seems to work fine nothing showing up on Diagnostic

Fuel pump seems to be working ok , fuel side of things looks good.

New cat and manifold so exhaust looks good.

However car starts to slow and revs cutback at about 50 mph moreso up hill

engine light shows when this occurs and goes out if /declutch clutch or drop revs a bit.

If revs kept constant , vehicle pulls uphill fine.

70 thou on clock

Now clutching at straws.

So 1 question
He changed plugs to these four pronged
pre factory set jobs
anyone had any bad experiences using these.

any other info gratefully recieved.

If you saw something similar posted a couple of months ago its still same problem.
BTIA

If the MIL (malfunction indicator lamp) has been flashing, codes should be stored in the ECU. Have you had the codes pulled recently? When was the fuel filter changed? Are you certain there isn't a blockage in the exhaust? The symptoms could be related to a whole mess of problems; those above are the most likely, however there are a number of other possibilities. If you are really struggling, I would suggest finding a Tech who has data streaming capabilities with movie, and taking the car on a run until the problem occurs. With such equipment, it shouldn't be too much of a problem getting to the root cause.

 

[Guest]

New cat and manifold so exhaust looks good.

[3]

However car starts to slow and revs cutback at about 50 mph moreso up hill

[1]

engine light shows when this occurs and goes out if /declutch clutch or drop revs a bit.

If revs kept constant , vehicle pulls uphill fine.
[2]
,snip>

any other info gratefully recieved.

If you saw something similar posted a couple of months ago its still same problem.
BTIA

Various bits snipped on above.
I think I would suggest that you have a blocked exhaust back box. as [1] and [2] suggest. [3] tells me that the exhaust rear of the cat has not been changed.
Dave

 

[Alan (archive)]

It sounds as if you have changed a lot of things but why?

I would normally check it on tech2 first to see what the stored codes are and work from there.

With regards to plugs, buy genuine Vauxhall ones (they are cheap) and there can be no question of incompatibility.

 

[CapStick]

It sounds as if you have changed a lot of things but why?

I would normally check it on tech2 first to see what the stored codes are and work from there.

Thanks to all for their answers thus far.
Where the cat had been changed i found that they had cut off the new plug and just crimped and taped wires to the new cat wires .

These were all loose or falling out, however after sorting this out the problem still persists Cleaned all plugs. they looked a nice light brown Still no joy will try exhaust tommorow

The one constant thing in all this is that
when in tickover
Boot down hard produces a situation where the revs go up in absolute stages. 1k to 2 k then engine hunts for a bit 2k to 3k then hunts again 3k to 4 and so on. If accelerator pressed slowly engine revs go up in a smooth manner. The Canned History of this problem

It was checked on a diagnostic more than once by main dealers some 6 months ago

At various different times they have,
via the diagnostic error codes,
put the problem down to cat,idle air valve and egr valve.

The work was all carried out by dealers in kent.

The problem still persist.

However tried ringing my local (Cornwall) vauxhall dealer today

asked for a price to have it put on a diagnostic
was informed this would be about £30.00 inc vat ( reasonable ) but was then told the following -:

A Diagnostic would only show last error and whatever it showed it may not be that part that is faulty, because a diagnostic will only show in what area to search for the problem.

I then said that according to the manual,
the error values reset at every tenth start
so therefore there should be one in 10 chance of showing the last ten error codes.

No says he,it would only show the last error.

He than said
What people normally do is bring it to us and we will investigate and put it right.

As my son has spent a bloody fortune on this car already and got nowhere with other so called 'Main dealers ' handling the job.

I am very unwilling to let anyone take yet more money.

Is there any other way i can
a- read any errors myself
b - get someone other than a main dealer to give me a 'proper' reading.

(Ps My own old car has a Distributer and points with No Electronic EMS as such HooBloodyRahhhh )

 

[malcolm]

Thanks to all for their answers thus far.
Where the cat had been changed i found that they had cut off the new plug and just crimped and taped wires to the new cat wires .

These were all loose or falling out, however after sorting this out the problem still persists Cleaned all plugs. they looked a nice light brown Still no joy will try exhaust tommorow

The one constant thing in all this is that
when in tickover
Boot down hard produces a situation where the revs go up in absolute stages. 1k to 2 k then engine hunts for a bit 2k to 3k then hunts again 3k to 4 and so on. If accelerator pressed slowly engine revs go up in a smooth manner. The Canned History of this problem

It was checked on a diagnostic more than once by main dealers some 6 months ago

At various different times they have,
via the diagnostic error codes,
put the problem down to cat,idle air valve and egr valve.

The work was all carried out by dealers in kent.

The problem still persist.

However tried ringing my local (Cornwall) vauxhall dealer today

asked for a price to have it put on a diagnostic
was informed this would be about £30.00 inc vat ( reasonable ) but was then told the following -:

A Diagnostic would only show last error and whatever it showed it may not be that part that is faulty, because a diagnostic will only show in what area to search for the problem.

I then said that according to the manual,
the error values reset at every tenth start
so therefore there should be one in 10 chance of showing the last ten error codes.

No says he,it would only show the last error.

He than said
What people normally do is bring it to us and we will investigate and put it right.

As my son has spent a bloody fortune on this car already and got nowhere with other so called 'Main dealers ' handling the job.

I am very unwilling to let anyone take yet more money.

Is there any other way i can
a- read any errors myself
b - get someone other than a main dealer to give me a 'proper' reading.

(Ps My own old car has a Distributer and points with No Electronic EMS as such HooBloodyRahhhh )

I would be interested to know the rate of crosscounts from the oxygen sensor. Usually there are approx. 6 per 10-seconds, that's to say that the sensor should rise and fall passed the 500mv point 6 up and 6 down every 10-seconds. This can be checked with a dc volt meter on the signal wire of the sensor. Poor sensor response WILL cause stepping in the rpm range, but test the sensor before replacing.

 

[malcolm]

Forgot to include that this test should be performed at approx. 2500rpm.

 

[CapStick]

not put
I would be interested to know the rate of crosscounts from the oxygen sensor. Usually there are approx. 6 per 10-seconds, that's to say that the sensor should rise and fall passed the 500mv point 6 up and 6 down every 10-seconds. This can be checked with a dc volt meter on the signal wire of the sensor. Poor sensor response WILL cause stepping in the rpm range, but test the sensor before replacing.

Cheers again

I will sign on and let you know progress late tommorrow night

 

[Alan (archive)]

You have no obligation to let them do any repairs. I think it is still worth getting them to do a Tech2 test and report all trouble codes and then give you a written estimate for the repairs.

This will then give you details of the codes and also the recommended work.

You can then make a decision whether to get them to do the repairs or do them yourself.

 

[Bilko130]

Hi,
Symptoms you describe seem to me, to suggest Mass Air Flow sensor. I have changed literally hundreds of these for the same symptoms as above. Find a mate with a 1.0 ltr or a 1.2ltr 4 cyl. They are the same part numbers I believe. Swap them over and test the car. The Tech 2 test usually does'nt show up this fault and, can throw up some red herrings. E.G. Lambda sensor,and is due to a rich mixture( or so it thinks)due to low flow readings and throttle position sensor readings being to high for MAF values. Hope this helps Bilko130 (Ex Vx Tech)

 

[CapStick]

Hi,
Symptoms you describe seem to me, to suggest Mass Air Flow sensor. I have changed literally hundreds of these for the same symptoms as above. Find a mate with a 1.0 ltr or a 1.2ltr 4 cyl. They are the same part numbers I believe. Swap them over and test the car. The Tech 2 test usually does'nt show up this fault and, can throw up some red herrings. E.G. Lambda sensor,and is due to a rich mixture( or so it thinks)due to low flow readings and throttle position sensor readings being to high for MAF values. Hope this helps Bilko130 (Ex Vx Tech)

Following some instructions received
I removed MAF plug
(Mass Air Flow sensor)

Immediate improvement in drive.
No pull back when pulling up hill etc.etc.
still a bit poor in low pulling away
otherwise 1000 percent improved ( Must Be The MAF)

so you along with another op do appear to be correct Bilko

Only problem now is
1
where do i get a cheap one they are priced at
wait for it
£234.00 +vat ( for a piece of what ?)

2
Is there a way to test the existing one ( lot of money wasted if i'm wrong)

3
Is it possible to repair the one i have If not why not.

 

[Alan (archive)]

Capstick's diagnosis was sensible and logical and appears to be the correct one. The question is, why have you paid for so many other parts as part of a trial and error replacement process?

Diagnosis beats experimenting every time.

 

[CapStick]

Capstick's diagnosis was sensible and logical and appears to be the correct one. The question is, why have you paid for so many other parts as part of a trial and error replacement process?

Diagnosis beats experimenting every time.

Well alan
The rest of the thread did say, that following diagnosis by main dealer (Vauxhall)

on there advice, all the parts were on various different occassions, fitted and charged for by them.

Another poster pointed out that the Diagnostic does not show a MAF error

So that was why all the other parts were fitted.
In other words the main dealer tossers only saught to line their pockets.

But i swear to god they will rue the day that i came into possesion of a car whose parts are priced using what can only be described as legalised fraud.

Before i am finished i will be making my own electronic parts rather than pay their Exhorbitant prices.

I shall post an explanation later on how to get a MAF Sensor for at least £115.00 cheaper than main dealer.

 

[Bilko130]

Capstick's diagnosis was sensible and logical and appears to be the correct one. The question is, why have you paid for so many other parts as part of a trial and error replacement process?

Diagnosis beats experimenting every time.

Alan,
I Disagree. As you are "Vx Involved" you must agree there are times when you simply must change a component because, you suspect this to be the problem. Even Vx tech info are advocates of this approach. And, with a case no. will pay for R+I x2 I personally, only found this fault by subsitution and then, thorough diagnosis as to why. I wonder how many Lambda sensors have been changed (to no avail) to try and rectify this fault? Regards Bilko130

P.S. How are things in the Vx world?

 

[CapStick]

"Alan" wrote:

Alan,
I Disagree. As you are "Vx Involved" you must agree there are times when you simply must change a component because, you suspect this to be the problem. Even Vx tech info are advocates of this approach. And, with a case no. will pay for R+I x2 I personally, only found this fault by subsitution and then, thorough diagnosis as to why. I wonder how many Lambda sensors have been changed (to no avail) to try and rectify this fault? Regards Bilko130

P.S. How are things in the Vx world?

Mass Air Flow Sensor from main dealer (Maynes Garage RedRuth) was £264+vat When ringing local Mill Auto Supplies( Edmunds Walker As Was) they initially said it was a Main Dealer part. However i took the part into them and showed them the Bosch Part No One phonecall later by them to their Bosch Supplier. Mass Air Flow Sensor From Mill Auto = £165.00+Vat This is a saving of roughly £115.00 once vat is added to both prices I then tried this at a local AutoSpark Place Cornish Electro Diesel ( CED ) they were £160+VAT another £5.00 + vat Saving

But the best was that after some ringing round
I found a second hand spare.
from a breaker
for the Princely Sum Of
£10.00 + VAT ( I dont yet if it works will let all know Tommorow) If It Does You Should be able to see my grin in the Outer Hebrides. Thanks to all for their Advice So Far.

 

[Alan (archive)]

Well done on finding the s/hand unit. I hope it works. I hadn't realised the pricing anomaly with the Bosch part. I will take this up with vauxhall.

 

[steveb]

Well done on finding the s/hand unit. I hope it works. I hadn't realised the pricing anomaly with the Bosch part. I will take this up with vauxhall.

try them on lambda sensors too, while you are at it

 

[CapStick]

"Alan" lifted the trapdoor, peered around

try them on lambda sensors too, while you are at it

Did you see me Grin

No where in any manual i have read does it say clean the MAF as a part of servicing or troubleshooting for that matter Haynes fails again

So if you find your car acting up something rotten and your getting nowhere with it try unplugging the MAF and running the car. if you see a marked impriovement in performance then clean The Maf

The new (second hand part) has transformed the car to what it was six months ago. I believe because of the failure of the MAF its had New EGR valve ,New Air Inlet Valve and New Plugs.

It may also have been responsible for having to have a new Cat because of failed emissions test. (not sure on this one)

I have since discovered that all i really had to do was very carefully spray clean the MAF with carb cleaner and i would not have needed the new (second hand) part either.

Before i asked on the Ngs i knew very little about Engine Management Systems. Their affect on the performance of an engine, should the peripherals of the system break down or become clogged etc .

I am through these NGs a lot wiser now and i thank all here.

I have made sure to finish off this thread so it makes it intact to the Archives for the future use of some other budding Amateur Mechanic.

I would also add this link that was so useful and explanatory It just goes to show that it doesn't necessarily have to be the same model of car just to get an answer to what you are looking for. How to clean your MAF http://www.fordscorpio.co.uk/cleanmaf.htm

Finally special thanks to TIM for advising removal of MAF to test this for fault in first place.