Sensory Perception

[ChimpOnGas]

This is one for Canems users really.

If anyone is suffering engine hesitation issues I recommend replacing the no name pattern part Vauxhall MaP sensor that comes with the Canems installation, and replacing it with a far superior Japanese quality MaP sensor from NTK.







I've been chasing down my frustrating hesitation issue for a long time now which I finally pinned to a poor quality MaP sensor, this was completely resolved by fitting NTK part no 92477 and shows us the importance of fitting good quality engine sensors. With the ECU completely relying on the manifold absolute pressure sensor output signal to establish engine load a quality sensor with good resolution is absolutely essential, and NTK make excellent quality engine sensors.

The market is flooded with poor quality Chinese made Vauxhall MaP sensors so given a proper quality NTK sensor is only £28.72 it's really not worth saving a few pounds on the cost of a Canems installation by fitting poor quality sensors.

https://www.ebay.co.uk/itm/NGK-NTK-MAP-Intake-Mani...

Its also worth noting that MaP sensors do not like getting wet so I would also recommend relocating the sensor, fitting it directly under the screen below the below perforated panel is not a great idea as it gets drowned in wet weather.



Fitting a proper Japanese quality NTK 92477 and relocating it not only completely eliminated the hesitation issue I've been suffering for years, it also delivered marked improvements in idle quality and drivability too. To be honest the difference is so profound I can only assume the no name pattern part MaP sensor supplied with my Canems installation was faulty from new.

I hope this helps other Canems users, the system is fundamentally excellent which is why its so important you don't try to save a few quid by fitting poor quality engine sensors and pattern part idle valves, because as I've discovered to my cost this will only lead to trouble.

[ed_crouch]

+1

False economy. For my last MS install I did allow a couple of no-name parts onto the car, but I had no problems with those at the time. Probably just luck.

This time I am not doing that. VR sensor - Hella. Cam HE sensor - Honeywell. The rest of the T&P sensors are Honeywell PX2 / PX3 srs. Coil packs - NGK.

If you shop around a bit you can have the top quality bits for actually not a huge amount more than the no-name stuff.

[ChimpOnGas]

ed_crouch said:

+1

False economy. For my last MS install I did allow a couple of no-name parts onto the car, but I had no problems with those at the time. Probably just luck.

This time I am not doing that. VR sensor - Hella. Cam HE sensor - Honeywell. The rest of the T&P sensors are Honeywell PX2 / PX3 srs. Coil packs - NGK.

If you shop around a bit you can have the top quality bits for actually not a huge amount more than the no-name stuff.

I really couldn't agree more, the importance of using proper high quality and genuine trusted brand name engine sensors can not be overstessed!

If you are putting together an engine management system and selling it on a commercial basis to the general public I can see why it might be tempting to fit cheaper components as it allows you to offer your kits and istalalations at a more competitive price, if your price point is lower than your competetors you may well indeed enjoy more sales, well in the early days at least.

But this is a false economy, make no mistake fake Chinese Bosch PWM idle valves do not work like the genine article, and cheap engine sensors are equally as bad if not worse.

I've found these components to be of substandard quality, the thing is while they may work well enough for the engine to run acceptably its not until you replace them with proper quality components you realise just what a false economy the cheap stuff is.

An engine management installation is already a complex exercise where many pitfalls await the inexperienced, a good wiring loom and earthing best practice are esential but even if you get this perfect all your good work can be undone in a stroke because you tried to save a few quid on what are absolutely critical components.

Fault finding can then become a very complex process, and of course if the car drives acceptably in the mind of the installer he will be unlikly to ever question his work.

I freely admit I have very high expectations for the way my TVR drives, indeed some may consider me verging on the obsessive compulsive... but I know how good my car could potentially drive on my Canems system so I have tirelessly walked the car step by step to where it is now which I consider to be night and day better than its ever been.

It's all about standards in my opinion, what might be perfectly acceptable to some are for others like me room for significant improvement. After much frustration I decided to do what I've always found in life to be the best approach, I took on the challenge of perfecting my engine management installation myself and the results have been transformational.

In my case it was a process of correcting lots of little things like resolving earth loops others created so understandably failed to find, sorting out my very poor battery terminals/cable connections that should never have been missed, resolving poor earthing issues, removing faulty components such as the cheap no name fake Bosch idle valve and fitting all new decent quality engine sensors.

I now have a manual fast idle extra air system, new battery terminals and cable connections, vastly improved earthing, a genuine Ford crank position sensor (properly gapped!), a new genuine Bosch lambda sensor and of course the excellent new NTK MaP sensor presented here.

I got rid of the way the lluminated element of my LPG switch had been earthed to the same ECU pin than switches from one fuel type to another which was clearly causing my earth loop issue! This was actually a safety issue as the ECU would loop the priming pulse feature with the ignition on pumping the inlet manifold and plenum full of explosive LPG, one day all this pressure actually blew my MaP sensor hose clean off the plenum fitting leaving me with yet another breakdown situation.

Oh and while we are on the subject of wiring I also found my lambda sensor loom had been crushed under two super tight cable ties pinning it to the chassis so causing a number of issues including a further earth loop it would seem... and this in addition to an LPG injector wire I discovered that had been pinched during careless plenum refitting when those very injectors were being mouted!

The crushed lambda sensor loom was a big one, no wonder my AFRs were all over the place, however apparently for some these jumpy air fuel ratios the ECU was trying to work with were perfectly acceptable!

Other lessons have been learned, my Canems installation ran two rad fan relays crudely screwed to my inner wing and I still have the two nasty holes as scars to prove it. The ECU earth circuit was clealy incapable of earth sinking two relays as the contacts of one would chatter killing many relays at my cost before I finally solved the problem myself (and again at my cost) by fitting the excellent and 100% reliable Davies Craig fan controller.

Its been a journey to say the least, and one I had to take ownership of myself as others were clearly failing to get it right despite being given countless chances (and cheques), my discoveries and the many improvements I've implemented have been slowly layered one on top of the oother over the last year to bring the car to where it is now, my TVR is finally delivering the superb results we should all expect from spending our hard earned cash on a stand alone engine management system installation.

I hope the above helps others, I was an early adopter and paid for this dearly, I'm sure much (If not all) of what I've listed above has now been discovered by others, so I'm sure what you get now incorporates all they've learned on their customers time as they slowly perfected their system and installation.

Dave.

[Sardonicus]

OE stuff every time not surprising I am using 4 Motorcraft (OE ford) generation 1 coils on my 2 Megasquirt installs not one of these coils is less than 25 years old because I have never witnessed one failure since production started in the late 80's of these generation 2 are not as robust sadly VR sensor genuine Ford these are new of course and sadly not as reliable IME but available new for a tenner , shame your finding out all this now Dave sort of puts a dampener on your whole Canems experience I'm sure its not right your having to re-evaluate whats fitted and what needs swapping out due to poor quality

Edited by Sardonicus on Tuesday 30th July 12:53

[ChimpOnGas]

Cut corners, pay twice!

That's the lesson here, and ultimately a message to certain proffesionals too.

Maybe I should make up an invoice to cover my consultation fees, this would at least go someway to compensate for my considerable inconvenience and personal costs.

But as always I offer this information freely, not really to support those who made the mistakes in the first place and at my expense, but to share my experiences with the TVR community in the hope it may help others.

Dave.

[pb450]

Interesting thread Dave, thanks for the heads-up.

Quick question, I assume the new MaP sensor is a simple plug and play. Simply replace old with new and off we go? I ask as my Canems system shows the faintest of hesitatins on a simple throttle blip. There's no detectable difference under normal running conditions but for every throttle blip there's a tiny delay before the revs pick up.

[LLantrisant]

the problem is nowadays that you cannot even trust well known brands....as the carton as well as the containment might be a chinese copy.

ever wondered why iridium NGK plugs have such a huge price difference? exactly: the ones are fake , the others not....this said: even the expensive ones could be fake, as the seller might be a "clever" guy.

[ChimpOnGas]

pb450 said:

Interesting thread Dave, thanks for the heads-up.

Quick question, I assume the new MaP sensor is a simple plug and play. Simply replace old with new and off we go? I ask as my Canems system shows the faintest of hesitatins on a simple throttle blip. There's no detectable difference under normal running conditions but for every throttle blip there's a tiny delay before the revs pick up.

The MaP sensor used on a Canems installation is just the super common GM part no 12 569 240, the original GM part is hard to source these days as this sensor was used on Vauxhall Corsas and many other cars from the mid 1990s through to the early 2000s, but there are lots of after market options out there from the cheapest Chinese copies to the far superior sensors offered by the likes of Bosch, Hella & NTK.

At this point we need to understand not all engine sensors are created equal, quality varies considerably and the ubiquitous GM three wire 5v MaP sensor is certainly much copied by our Chinese friends. Of course the Chinese can make great quality automotive products, after all they've been making Russian designed MiG fighter jets under licence for over four decades now and that's not a simple machine.

The trouble comes when engine management installers decide its a clever idea to buy critical components like idle valves and engine sensors on price only, eBay is a wonderful place to buy everything and anything but its just a buying platform so we shouldn't make eBay the criminal here as there are many good sellers and genuine products being sold on eBay. But it's powerful search tools can also lead you to unscrupulous sellers when you try to find the cheapest parts you can, this is where things go very wrong as people will often end up with very poor quality fake Bosch idle valves and similarly poor quality engine sensors.

Make no mistake these are sophisticated components, a smaller independent Chinese producer may me able to copy something so it looks identical but they seldom get the product performing exactly as an original part does because they just don't understand the finer complexities of its construction or know how to test it correctly.

Now we need to accept that all the big trusted automotive component makers such as Bosch and Hella have manufacturing plants in China, so in my opinion its less about where something is made and all about how well those powerful giants in the world of automotive components control the quality of their products. For example Hella are a trusted German brand but their version of GM part no 12 569 240 is made in China, I wouldn't think twice about buying this Chinese made Hella brand sensor because I know the Germans will be making 100% sure the quality of it is first rate.

Its the same with Bosch as their version GM part no 12 569 240 is made in Brazil, but I can tell you from personal experience having visited Brazil over 10 times their production quality can be world class, especially when again it's all quality controlled by the Germans who absolutely must protect the reputation of their brand by running to the very highest production standards. My NTK sensor wasn't actually made in Japan, it was made in Spain, but I know the Japanese are (even more than the Germans) fastidious when it comes to quality, that's why spark plugs from their sister company NGK are so unbelievably reliable.

NGK completely changed the way we thought about spark plugs in the 1970's, back then spark plugs often failed in just a few thousand miles or were faulty straight out of the box, the Japanese changed all that over night and while we were all still calling their cars JapCrap they were actually quietly busy showing the world how it was done. The Japanese helped bring down the British motor industry by simply making a far far better product and we made it easy for them because the truth is we were making utter junk in the 70's, we no longer call Japanese cars JapCrap we hold them up as the most reliable cars in the world because that's what they are.

I only use genuine NGK plugs purchased from Euro Car Parts and their cheaper but equally reputable sister company Car Parts For Less, and I only ever buy my wife Japanese cars because I know they're by far the most reliable, the Japanese obsession for quality and detail has been embedded in their society for hundreds if not thousands of years. The Japanese also have social shame mechanisms that ensures failure is not an option, I always say I want a car where if the designer gets it wrong he is required to jump on his own sword, that sharpens your mind I can tell you! This is why I chose a Japanese quality genuine NTK MaP sensor from a trusted seller and I'm glad I did, it may be made in Spain but I know the Japanese only accept one standard, PERFECTION!

I did my due diligence checks and my NTK MaP sensor is definitely a 100% genuine NTK item, no question at all!

https://www.ngkntk.com/uk/products/mapmaf-sensors/

My original MaP sensor on the other hand as supplied with my Canems installation was unmarked and of unknown origin, it was also proven to be the the reason my car suffered a minor but still very annoying hesitation issue for many years. Don't get me wrong the car generally drove well enough on this no name sensor and the car may have been considered acceptable to some including the installers themselves, but once I swapped it for the NTK sensor the car was transformed, the new Japanese quality MaP sensor was clearly in a different league.

These things can be difficult to pin down, the sensor delivers and interpretation of vacuum from 15kPa to 103kPa over a range of just 0-5v, and you just can't see a failing MaP sensor using the Canems software because things are happening way too fast, this is where you need an automotive oscilloscope, which in the world of engine management is probably the most useful diagnostic tool you can have. Only an oscilloscope will help you truly evaluate the resolution quality of your sensors, and only an oscilloscope will help you pinpoint a sensor fault that can cause issues such as my hesitation.

I don't want to repeat myself but its also worth noting that MaP sensors do not like getting wet so I would also recommend relocating the MaP sensor on any Canems installation if it looks like mine below, fitting it directly under the windscreen below the perforated panel is a terrible idea as its only ever going to get drowned during wet weather just like the wiper motor park switch does in fact!.



Not only is the MaP sensor subject to rain coming down the screen it's actually splashed with water when the wipers are on their down stroke, worse still if we take a look at a Chimaera bonnet design its not hard to see how when the car is moving at speed in the rain a certain amount of rain water gets channelled and blown down the rear most off side bonnet vent which is then aimed directly at the MaP sensor.



The three wires that connect the ECU to the MaP sensor may have a silicone gasketed 'Superseal' connector, these are good connectors if you buy quality ones but they are more light shower proof than submersible waterproof and I'm here to tell you a 'Superseal' connector is not a complete solution here.

My hesitation became much worse in wet weather, so absolutely no question whatsoever the sensor desperately needs relocating to a place where its dry but is also not cooked by the exhaust manifolds, it most certainly should not be in a place where it will get wet when it rains as shown above

[pb450]

ChimpOnGas said:

it most certainly should not be in a place where it will get wet when it rains as shown above

Could a little aluminium 'roof' be made and bolted above it to keep the majority of rain water from landing on it? Not an attempt to waterproof the component, just an effort to deflect direct rainwater. Clearly this location has some benefits and ticks the 'not cooked by the zorst manifolds' box. Just a thought...

[ChimpOnGas]

pb450 said:

Could a little aluminium 'roof' be made and bolted above it to keep the majority of rain water from landing on it? Not an attempt to waterproof the component, just an effort to deflect direct rainwater. Clearly this location has some benefits and ticks the 'not cooked by the zorst manifolds' box. Just a thought...

To be fair the best place for it would be in the warm and dry but away from all sources of heat and vibration, to my mind thats at the ECU like the integrated MaP sensor you get with many after market ECUs.

But if that fails you're in for some ECU surgery so I kind of like the good old Vauxhall Corsa MaP sensor, relocating it under the dash is my current thinking but you do also need to get to the thing if it fails so that might be a pain if your dash is still bolted down.

I'm still in new sensor experimentation mode, and as I didn't want to mess with the existing wiring until the new sensor was a proven fix for my annoying hesitation this limited my placement choice, so as a temporary measure I fixed it to my throttle mechanism bracket which gets it out of the wet and is easy to get to, and without the thing getting any more cooked that it was in its original place.

This seems to be working well but I feel a nice warm cosy location under the dash would still be a better solution, of course like this the vacuum hose needs to run through the bulkhead and the wiring needs extending but that's not a big job.

I've already bought the correct connector to complete the wiring element properly, but the main thing for me right now is the new NTK MaP sensor is already delivering an absolutely outstanding improvement right where it is!

Its important to point out I was an early Canems adopter so the installers choice of sensor brand may well have changed by now, and for sure over the last few years they will have learned what are good reliable components and what is total junk.

Talking of junk I really hope they've stopped using these dreadful Chinese waterproof fuse holders.



I've had two breakdowns now as a direct result of these dreadful things

[Classic Chim]

It’s not just the Canems users though is it!
Mines out in this rain with no cover for days and mines just got wet by opening the bonnet to look
Being a later car I have no wiper mechanism there, might be the stainless mesh but water doesn’t drip on mine and parked the wiper blade directs water well away. Rain water is forced backwards while moving.

I’ve washed my car a 1000 times and possibly 20 times since Mbe, it rarely gets wet but is tucked back and nicely seated rather than some nasty piece of bent alloy what looks like self cutting tech screwed on and placed directly under the edge of the mesh,,,, where it will get wet.

Maybe all Mbe users should ask for a re call to address this issue Dave so kindly illuminates,
I’m sure Dom has got it all wrong.

Faff over nothing and a bit of cutting and carving could have saved your sensor by just removing that shed made lump of alloy and the damn thing mounted flush on the fire wall well behind the line of water fall,,,,,,,
I can’t believe with all your mechanical skills Dave you ever let that sensor sit like that directly under the line of water let alone for years,,,,,, if it’s been getting so wet why has it taken you so long to identify this issue then kindly remind us that anyone else with a sensor there is risking hesitation or whatever you seem to think is going to go wrong based on that poor add on your car....



Here’s mine, ITS NOT A PROBLEM FOLKS and if it was I’d have plagued Dom and Jason the mapper and install tech at Powers I can tell.
Gladly for Dom it’s not an actual thing this issue Dave so kindly tells us of, so according to this insightful thread every Mbe and probably Canems Ecu install has an inherent problem that needs to be addressed as in the sensor is in the wrong place and doomed to fail unless it’s moved as per Dave’s helpful tip.
If he’d just moved his and got rid of the nasty bracket that actually moves the sensor directly in line with falling water which is brainless and needed attention from day 1 then he wouldn’t be on here now suggesting half the Tvr world have to change their practice.

Very insightful thread

Edited by Classic Chim on Tuesday 30th July 21:52

Just look where the stepper motor wiring sits,,,,,, mines removed and blanked off but see my point!
Hilarious

Edited by Classic Chim on Tuesday 30th July 21:55

PS sack the ham fisted mechanic that’s ruined your mesh too, name and Shame please Dave, that sucker ain’t going near my car

Only playing,,,,,,, people’s businesses are in question hmmmm

Edited by Classic Chim on Tuesday 30th July 22:02

Edited by Classic Chim on Tuesday 30th July 22:31