20 replies to this topic

[Gouldy]

Bear with me here I know the wet spark plugs & coil (dis) pack thing has been covered. (Unlike the top of my engine which is ingress kit-less). But I have a theory which I'm hoping one of our more engineering-ey or mechanic-ey members might be able to support or shoot down.

Can a poor spark be 'blown out' by high intake pressures? This in hinted at in THIS post.

My reason for asking is that my VXT has started misfiring, BUT only when under load and when the turbo is creating boost. This causes the EML to come on and the ecu to cut back to 3 cylinders. If I stop the engine, even for a few seconds and restart the EML is extinguished and it runs normally. Until I put my foot down.

What is baffling me is that there must be a spark when the engine is under little load, but this spark dies when the intake pressure reaches a certain level.

Also does the ecu sense this lack of combustion and shut the cylinder down? Hence, why a restart resets something and lets the cylinder fire again?

I have dried the spark plug wells out and have some new plugs on order. I'm hoping the source of my hypothesised 'poor spark' is a dodgy plug, and the the coil pack is okay!

Any views, corrections, or anyone who is still awake, much appreciated.

[danuk]

I doubt thats that case but it could be. If you have been haveing problems for a while with the engine misfiring due to water ingress or other problem this can damage the dis pack. have you tried new plugs

[ChazUwe]

Faulty AMM?

[Gouldy]

Faulty AMM?

Could be I guess, in that the turbo could draw the air through it too quickly for it to cope when under boost. If the AMM is faulty why would the ECU cut a cylinder (or two)?

Also, having said that there was a little water in one of the spark plug holes, so I was rather hoping it was that!

[paulf-cam]

Yes, a poor spark could be blown out by high cylinder pressures. The higher the pressure in a cylinder, the more difficult it is for a spark to fire. However, it sounds like a faulty DIS pack to me... Get the ingress kit fitted and replace the DIS. Cheers, Paul.

[siztenboots]

Bear with me here I know the wet spark plugs & coil (dis) pack thing has been covered. (Unlike the top of my engine which is ingress kit-less). But I have a theory which I'm hoping one of our more engineering-ey or mechanic-ey members might be able to support or shoot down.

Can a poor spark be 'blown out' by high intake pressures? This in hinted at in THIS post.

Also does the ecu sense this lack of combustion and shut the cylinder down? Hence, why a restart resets something and lets the cylinder fire again?

I have dried the spark plug wells out and have some new plugs on order. I'm hoping the source of my hypothesised 'poor spark' is a dodgy plug, and the the coil pack is okay!

Any views, corrections, or anyone who is still awake, much appreciated.

Changed my original VXL plugs for NGK Iridium ( £30 from TMS ) . Plug 1 ( nearest connector ) HT connector had a greenish mildew like colour as if water had got to the bottom. All the plugs had a brown rust on the insulator just above the 10mm nut. I did not have misfires, or loss of power.

But having changed them to Iridium the engine straight away sounding sweet, had lost the gruff note . I am changing to a plug more suited to the worst trackday condition like last summer .

[Gouldy]

paulf-cam: Cheers for the answer to the original question. Definately feels like that is what was happening. sizetenboots: It was plug 1 in mine that was damp too, but a combination of a rag, some wd40 and a good run at the weekend means it seems to have stopped the misfire totally now. I have some nice new NGK Iridium plugs on my desk as we speak so I'll put them in at some point this week. Still hoping the coil pack doesn't need replacing, it certainly feels okay at the moment. And yes, I guess I should get the ingress kit fitted, but they just look a bit pants to my eye!

[siztenboots]

paulf-cam: Cheers for the answer to the original question. Definately feels like that is what was happening.

sizetenboots: It was plug 1 in mine that was damp too, but a combination of a rag, some wd40 and a good run at the weekend means it seems to have stopped the misfire totally now. I have some nice new NGK Iridium plugs on my desk as we speak so I'll put them in at some point this week.

Still hoping the coil pack doesn't need replacing, it certainly feels okay at the moment. And yes, I guess I should get the ingress kit fitted, but they just look a bit pants to my eye!

You will need a 10mm SP socket, T30 Star drive , and an extension bar to reach down to the plugs ( make sure you securely tape the socket to the extension bar ).

Mine has the ingress kit fitted

Edited by siztenboots, 04 December 2006 - 12:19 PM.

[Rickyk]

I'm just about to pick up a turbo in a few weeks time, and noticed that it did not have an ingress kit. Its a 53 plate and am wandering whether Vauxhall sorted out the problem on later models or whether the ingress kit would be a wise buy as my car will be outside as I have no garage. I've read lots about the kit but am unsure whether or not I will need it. Also if I do where can I get hold of the stainless steel one that was mentioned before in a thread as opposed to the black one? Cheers, Richard

[P11 COV]

I had a misfire problem on and off for quite a while. Spraying the plugs with WD 40 etc cured it but it would always come back. New set of plugs and hey presto the car was like new again. The plugs were looking little rusty and past thier best.

[Thorney]

Paul is spot on, we normally advise smaller gap higher temp plugs for stage 2 cars as the higher boost can effectively blow out the spark, sounds like this is whats happening. You need a 0.8mm gap Iridium NGK plug, they cost about £25 for a set.

[Guy182]

http://www.sparkplugs.co.uk


Iridium plug, vx220 turbo

NGK--BKR5EIX 5.50 each 22.00 for set of 4

--------------------------------------------------------------------------------
Subtotal 22.00
Delivery 1.76
Tax VAT 4.16

--------------------------------------------------------------------------------

TOTAL 27.92

[Gouldy]

http://www.sparkplugs.co.uk


Iridium plug, vx220 turbo

NGK--BKR5EIX 5.50 each 22.00 for set of 4

--------------------------------------------------------------------------------
Subtotal 22.00
Delivery 1.76
Tax VAT 4.16

--------------------------------------------------------------------------------

TOTAL 27.92

That's where I got mine from, just haven't fitted them yet. Except I bought bkr6eix with a .8mm gap as recommended in a number of posts on here.

Good service from that site though. Ordered them at about 3 pm on Friday, they were delivered Saturday!

Edited by Gouldy, 04 December 2006 - 09:53 PM.

[Rickyk]

OK, but no one answered my post on the ingress kit

just about to pick up a turbo in a few weeks time, and noticed that it did not have an ingress kit. Its a 53 plate and am wandering whether Vauxhall sorted out the problem on later models or whether the ingress kit would be a wise buy as my car will be outside as I have no garage.
I've read lots about the kit but am unsure whether or not I will need it

hope someone can help, cheers, richard

[Guy182]

whats the ingress kit actually look like?? dont know if ive got one or not.

[Gouldy]

whats the ingress kit actually look like??

dont know if ive got one or not.

The vauxhall ingress kit is a piece of black painted metal which fits onto the underside of the VXT engine cover and covers the top of the engine. It looks a bit like the stainless steel one made by a member for their NA at the bottom of this thread:

Clicky

In answer to your question RickyK, in my experience you should get one. I've had my 53 plate VXT for 3 years, up until 2 months ago it was garaged and I never had a problem, now that it lives outside the rain seems to be getting in. Also, they only cost about 15 quid apparently from your friendly local parts dept.

HTH.



(Edited to change material ingress kit is made from - apparently it's metal not plastic).

Edited by Gouldy, 04 December 2006 - 10:21 PM.

[Guy182]

http://www.sparkplugs.co.uk


Iridium plug, vx220 turbo

NGK--BKR5EIX 5.50 each 22.00 for set of 4

--------------------------------------------------------------------------------
Subtotal 22.00
Delivery 1.76
Tax VAT 4.16

--------------------------------------------------------------------------------

TOTAL 27.92

That's where I got mine from, just haven't fitted them yet. Except I bought bkr6eix with a .8mm gap as recommended in a number of posts on here.

Good service from that site though. Ordered them at about 3 pm on Friday, they were delivered Saturday!

sorry my bad, the 5's i posted were standard replacements.. the 6 you mention are the grade cooler like thorney suggested in his post up there ^^

yeah they are good service and cheapest place i found when ive ordered from them in the past!

[Jive]

You should buy the ingress kit if its going to be parked outside a lot, water getting into the wells also caused mine to drop to 3 cylinders on a couple of occasions. Its only £15 or so, so you have no excuse not to.

The ingress kit is usually a black plate bolted to the underside of the boot which shields the top of the engine from the rain, its roughly the size of the top of the engine and the reason some people don't like it is because they cant read Turbo when they look through the grill into the engine bay anymore.

I'm confused with the spark-plugs Thorney, should we be using the NGK--BKR5EIX Gouldy pointed out or are NGK--BKR6EIX the ones with the smaller gaps that we should be buying if we have a stage 2? If its neither of the above can you let me know.

Bit off topic i know but have you done a fuel test with Vmax yet? i know you did with the optimax and tesco 99ron, just wondered how the stack up today?

Edit: ok my spark plug query was answered while posting myself

Edited by Jive, 04 December 2006 - 10:22 PM.

[Rickyk]

You should buy the ingress kit if its going to be parked outside a lot, water getting into the wells also caused mine to drop to 3 cylinders on a couple of occasions. Its only £15 or so, so you have no excuse not to.

The ingress kit is usually a black plate bolted to the underside of the boot which shields the top of the engine from the rain, its roughly the size of the top of the engine and the reason some people don't like it is because they cant read Turbo when they look through the grill into the engine bay anymore.

I'm confused with the spark-plugs Thorney, should we be using the NGK--BKR5EIX Gouldy pointed out or are NGK--BKR6EIX the ones with the smaller gaps that we should be buying if we have a stage 2? If its neither of the above can you let me know.

Bit off topic i know but have you done a fuel test with Vmax yet? i know you did with the optimax and tesco 99ron, just wondered how the stack up today?

Edit: ok my spark plug query was answered while posting myself

was it?

ok my spark plug query was answered while posting myself

and the answer is?

[Jive]

Guy182 confirmed that as a standard replacement NGK--BKR5EIX should be used While NGK--BKR6EIX should be used for stage 2 cars.