Secondary Ignition scope analysis

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Technician
TwoWaves
TwoWaves
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Re: Secondary Ignition scope analysis

Post by Technician » Fri Aug 09, 2019 7:10 pm

Not sure how or why the bits settings between the two scope traces above are between 12 and 16 bits, and the offset at a value of 1.0. In the channel A I only selected wasted spark positive and changed no other settings. I can see now what Iver is saying about the negative voltages. These negative voltages actually don't exist if I use the Mixmaster to record the cylinder ignition voltages. I've used both a manual setup and automotive menu and can see problems in each method used. I'm not sure what I'm up against at the moment, either equipment or car faults, but I know one thing for sure and that is the Fiesta engine starts and runs brilliant and presents no drive-ability problems at all. As far as confidence in diagnostics is concerned at the moment that is nil. Given the loss of communications I get with the scope and freezing up of the scope, and the problems I think I have also had with previous pc's, its not difficult for anyone really to understand why confidence would be low.

At work I bought what I thought was a new pc. While this pc is working I have yet to test it using four channels of the scope when demand is requested from the pc.

This Fiesta suffered from batteries discharging and customer complaints. The aftermarket telling me that silver calcium batteries were not required. Auto-electricians telling me that they had repaired faults in the alternator and that it was now working fine, only to find that later the battery still discharged. I fitted an OEM alternator from Ford myself, and a silver calcium battery myself, and now I can see the charging system works perfectly. The aftermarket told me what they wanted me to believe!

The cylinder head gasket leaked on this Fiesta, a garage said that oil was in the coolant. I was asked to recover this car, and before going for it I advised that I thought the oil cooler would be the cause of the oil in the coolant. Nobody accepted what I said. I recovered the car and asked engineers with over 30 years experience in engine reconditioning if they had the facilities to test oil coolers and they said they had. I took the oil cooler, the transmission cooler and the cylinder head along to the engineers for repairs, testing etc and when I picked up the parts they said the oil coolers were fine and OK.

After rebuilding the engine the cooling system filled with oil again. My colleague thought I had not torqued the cylinder head down sufficiently at 75 degrees, and I said that is Ford's spec and he said he thought I'd misread it. We double checked it and it was correct. I then lost my confidence thinking that 75 degrees was not enough, so I lifted the cylinder head off and inspected the head gasket and found that the clamping loads were not all evenly distributed, however the gasket was not leaking. I purchased another gasket and those instructions that came with it added a further 90 degrees angle torque over and above the 75 degrees.

After rebuilding the engine a second time and flushing out the oil in the coolant I ran the car for another 100 to 150 miles. The cooling system filled up with oil again. I decided to buy an oil cooler from Ford directly. After fitting and running the car again for another 200 miles there is NO oil in the coolant. I rang the engineers and spoke with them nicely and they said to me why is it that ONLY YOU say our testing methods are flawed and no other main dealer we test oil coolers for every come back complaining?

Who then is correct!

I put the OEM oil cooler on and have had no further problems. The engineers said they tested the original oil cooler and found no problems with it, yet the cooling system kept filling up with oil.

Confidence cannot be built or established when everything I am doing is falling apart at the seams because I have no confidence in the trades ability to test or fix anything properly, and any equipment I buy is flawed so the confidence cannot be built in myself either because of equipment failures.

So Iver, please don't answer questions with a question as I have no confidence in either the trade or equipment at this time. I don't mind buying and investing in new equipment to do the job, but what I am buying is not what it says on the tin. I have no confidence now.

Technician
TwoWaves
TwoWaves
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Joined: Thu Apr 24, 2014 8:32 pm

Re: Secondary Ignition scope analysis

Post by Technician » Mon Aug 12, 2019 8:39 pm

I've done some more ignition scope tests this evening. They look a lot better and I think the main problem is how I'm setting up the scope and whether the leads connected to the plug leads are very sensitive and allowing interference?

I decided to pass the leads through the bonnet hook and let them hang individually to each cylinder. The traces look better.

Two things I've noticed, one was previously pointed out by Iver but I can't answer it, and that is about the negative voltage being pulled down. The other area I have seen is the firing line on cylinder 4 is lower than the remaining three cylinders, where they all show 20 kv. The lower firing line could be the spark plug as I'm advised the spark plugs have never been changed!

Reading through the buffer and being a wasted spark system I'm also thinking that careful understanding of the ignition waveforms must be considered because some points of the traces will be fired negatively, and hence the voltage requirements at the spark plug will be considerably less, and I'm also thinking that when the cylinder is firing in the wasted region, then the burn kv line could show up as a cylinder being lean?

This all a learning curve for me.

Iver
TwoWaves
TwoWaves
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Re: Secondary Ignition scope analysis

Post by Iver » Tue Aug 13, 2019 6:53 am

The aftermarket telling me that silver calcium batteries were not required. Auto-electricians telling me that they had repaired faults in the alternator and that it was now working fine, only to find that later the battery still discharged. I fitted an OEM alternator from Ford myself, and a silver calcium battery myself, and now I can see the charging system works perfectly. The aftermarket told me what they wanted me to believe!
Well that is not true ! I am in the Aftermarket and did not tell you that ?

With your posts it is always about this "Auto Electrician" "Advised" me this and that. Then a "Master Tech" "Advised" me the other.

Not my business where you find these people but generally the information in the post is, at best, questionable ! Every time !

Your Evening Seminars with Snap On are not going to make you anything of use when it comes to basic knowledge and understanding system function. The scope wont make a technician work good.

You have to be a technician to make the scope work !!

There in lies the problem. Premature purchase of scope possibly ! We are still struggling with fitting the right battery first time. It is an indelible blemish on the trade and that rubs off on all of us. That is not right!

Taking Cylinder Heads off twice then find a fault in the Oil Cooler ?? What does that say to your paying customer ? and the motoring public ?

You don't know what you don't know. The basics are very near to non existant, time to focus there first.

speck
TwoWaves
TwoWaves
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Re: Secondary Ignition scope analysis

Post by speck » Tue Aug 13, 2019 8:36 am

Hi technician, I'm looking at your first post (screen 7) you are running at around 800rpm.Your cyl.4 shows
some odd behavior which is a characteristics of pico's secondary leads. The data is not valid anymore when
you see those jumps. There are 10000:1 leads available which are a lot better, but do it sometimes too .
Waste spark system is best checked at idle since you have the advantage to see a spark under no compression.
I hope that helps you a bit
Attachments
Secondary.jpg

Technician
TwoWaves
TwoWaves
Posts: 512
Joined: Thu Apr 24, 2014 8:32 pm

Re: Secondary Ignition scope analysis

Post by Technician » Tue Aug 13, 2019 12:13 pm

Iver wrote:
Tue Aug 13, 2019 6:53 am
The aftermarket telling me that silver calcium batteries were not required. Auto-electricians telling me that they had repaired faults in the alternator and that it was now working fine, only to find that later the battery still discharged. I fitted an OEM alternator from Ford myself, and a silver calcium battery myself, and now I can see the charging system works perfectly. The aftermarket told me what they wanted me to believe!
Well that is not true ! I am in the Aftermarket and did not tell you that ?

With your posts it is always about this "Auto Electrician" "Advised" me this and that. Then a "Master Tech" "Advised" me the other.

Not my business where you find these people but generally the information in the post is, at best, questionable ! Every time !

Your Evening Seminars with Snap On are not going to make you anything of use when it comes to basic knowledge and understanding system function. The scope wont make a technician work good.

You have to be a technician to make the scope work !!

There in lies the problem. Premature purchase of scope possibly ! We are still struggling with fitting the right battery first time. It is an indelible blemish on the trade and that rubs off on all of us. That is not right!

Taking Cylinder Heads off twice then find a fault in the Oil Cooler ?? What does that say to your paying customer ? and the motoring public ?

You don't know what you don't know. The basics are very near to non existant, time to focus there first.
Actually it might be better if you read the posts properly the first time before words get twisted around. Regarding the oil cooler, if you read the thread properly I said that I thought the oil cooler was the cause of the problem even before I went for the car.Engineers said it had tested OK. Clearly the evidence proved they were wrong. A new OEM oil cooler fitted cure the problem.

Regarding lifting the cylinder head off the block twice, doubt existed once the Ford technical information became questionable. The cylinder head gasket poor clamping load in various areas proved the angle torque provided by Ford was questionable. Another cylinder head gasket manufacturer advised the same torque settings but finished with + 90 degrees. The engine runs OK now, that is the evidence not the text books.

Now as your digging at me let's look at the first reply to the thread. You said that scope traces are not much good at idle, yes I thought about that but asked were they better at say 2500 rpm, you didn't reply. You then went on to say that the ignition traces had problems because they were showing negative values, yet even though I said I don't know why, you still work round answering that question.

The only problem I can see on those scope traces is cylinder 4, that'll be the firing line and burn KV.

You come across on this forum like another member that was banned a while back, makes me wonder?

Technician
TwoWaves
TwoWaves
Posts: 512
Joined: Thu Apr 24, 2014 8:32 pm

Re: Secondary Ignition scope analysis

Post by Technician » Tue Aug 13, 2019 12:17 pm

speck wrote:
Tue Aug 13, 2019 8:36 am
Hi technician, I'm looking at your first post (screen 7) you are running at around 800rpm.Your cyl.4 shows
some odd behavior which is a characteristics of pico's secondary leads. The data is not valid anymore when
you see those jumps. There are 10000:1 leads available which are a lot better, but do it sometimes too .
Waste spark system is best checked at idle since you have the advantage to see a spark under no compression.
I hope that helps you a bit
Thanks Speck, yes your correct and yes I have proven it to be the leads, however I still have a problem on cylinder 4, reference the firing line and the burn KV. I might get chance to look again tonight. Every day is a learning curve for me. :)

Iver
TwoWaves
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Re: Secondary Ignition scope analysis

Post by Iver » Wed Aug 14, 2019 5:34 am

Waste spark system is best checked at idle since you have the advantage to see a spark under no compression.
Really ?? Then why don't we check spark with the spark plug removed ? In atmosphere !!

I have always seen compression lower at higher Rpm then at idle too. Something not adding up here !

Technician
TwoWaves
TwoWaves
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Joined: Thu Apr 24, 2014 8:32 pm

Re: Secondary Ignition scope analysis

Post by Technician » Wed Aug 14, 2019 8:34 am

Iver wrote:
Wed Aug 14, 2019 5:34 am
Waste spark system is best checked at idle since you have the advantage to see a spark under no compression.
Really ?? Then why don't we check spark with the spark plug removed ? In atmosphere !!

I have always seen compression lower at higher Rpm then at idle too. Something not adding up here !
Iver, something wrong here mate, really!

While I will no doubt admit that this side of the trade I have not practiced for over 15 years, it had become a back seat and many professionals will easily see mistakes I now make. I used to have Crypton scopes back in the 1980's/90's, they were not perfect and nowhere near the integrity of today's equipment, but time and experience moves on.

We should try always to see the 'Other side' when we make replies to other peoples view points and understanding, sometimes we need a little guidance and sometimes professionals like yourself need a little guidance, so with that said, and please don't take this the wrong way, but what you wrote above tells me that your experience there originates from your own belief and experiences, but not practical based testing and experiences.

If you had the WPS500x pressure transducer from Pico, and used it for engine testing, and you had the basic training regarding 'volumetric efficiency', then from theory and practical engine testing you would know beyond doubt that;

As cylinder piston speed increases volumetric efficiency reduces. Basically this means that the slower the pistons move the more air induced into the cylinder, thus the compression pressure will be higher with a standard compression gauge at cranking speeds, because, first the gauge has a non-return valve fitted, which artificially creates a bench mark for the second compression stroke to start off from, which is incorrect, and secondly, the cranking speed of the engine is significantly lower than most normal idle speeds of a modern engine.

Now using the WPS500x pressure transducer, If you then rev up the engine from idle speed, the piston speeds increase and the time the cylinder has to fill with air is significantly reduced, but the compression pressures rise and this can be seen on the Pico scope WPS waveform. Therefore a dynamic cylinder compression test will increase the cylinder pressures when speed increases and not therefore reduce.

I hope this brings a little understanding to the subject. Please remember we are all here to learn from each other, and common sense isn't a flower that grows in everyone's garden. :mrgreen:

speck
TwoWaves
TwoWaves
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Re: Secondary Ignition scope analysis

Post by speck » Wed Aug 14, 2019 10:51 am

Iver wrote:
Wed Aug 14, 2019 5:34 am
Waste spark system is best checked at idle since you have the advantage to see a spark under no compression.
Really ?? Then why don't we check spark with the spark plug removed ? In atmosphere !!

I have always seen compression lower at higher Rpm then at idle too. Something not adding up here !
First of all I'm talking about waste spark system. When you see compression and exhaust firing on the screen,
it will tell you about the HT lead and spark plug. Compression KV high (idle) exhaust KV low. Easy to work out if you have a HT lead or spark plug problem. I hope that clarifies some for you, if not fine with me too.
speck
Attachments
waste spark.png

Iver
TwoWaves
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Re: Secondary Ignition scope analysis

Post by Iver » Wed Aug 14, 2019 7:11 pm

If you had the WPS500x pressure transducer from Pico, and used it for engine testing,
Which I have had for years, in fact I had pressure transducers and flow meters long before Pico bought their versions to market.

I have every accessory Pico sell and I need. NVH kit for 3 years, never taken out out of the box but its there.

I also have a valid understanding of when, where and how Air gets into the engine. Keeping on topic here, this is about Secondary measurement and analysis on a car that you report runs perfectly.

It is well documented around the globe that testing anything looking for errors is best achieved by loading and stressing that subject to force the error. For secondary ignition that is not going to be achieved at Idle, 1500 rpm or 2500 rpm. Cannot be achieved at any RPM really.



If you don't know how to stress it then you don't know how to stress it ! So your testing remains flawed in my humble ! Regardless of the fact if it is Wasted Spark or not. That's just a minor, the ignition system makes no difference whatever. We stress them all the same way, the right way.

There is an ideal time to look at secondary, Wasted Spark or not, and your captures are not taking that opportunity.

I think your trying to tell me that as RPM increases then there is less time for for air to get in so less air get in, which we learnt in school back in the 1970's. That is how I know !!

Incidentally
Therefore a dynamic cylinder compression test will increase the cylinder pressures when speed increases and not therefore reduce.
Completely wrong. That statement is only valid if you do the Dynamic Compression Test INCORRECTLY with a conventional analogue gauge.

I have done Running Compression tests starting some 39 years ago and the analogue gauge would show a lower peak compression with a rise in RPM. Perhaps you might be holding yours upside down. I don't now what you do ! Plagiarising perhaps ?
I hope this brings a little understanding to the subject.


Nothing that I didn't know 30 years ago and as above you are wrong about the dynamic compression testing using an analogue gauge
Please remember we are all here to learn from each other,
Yes. but not ignition basics ? This is not Honest John Forum for the ,,,......
and common sense isn't a flower that grows in everyone's garden.
Clearly not !!

Guess it is the quality of the Manure that the common sense flower sits on is a factor. The Foundation ?
Last edited by Iver on Thu Aug 15, 2019 6:28 am, edited 2 times in total.

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