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I am trying to get my car through the French "Controle Technique" and the only failure point at the moment is, unsurprisingly, the emissions check.

The car has been sitting around in the UK for the last 3 years, which I would guess is a contributing factor. I have replaced the fuel with nice fresh 98 RON fuel and intend to put around 500 miles on the clock before retesting. I have just fitted a new metering unit which should also improve matters.

The question is - are there any additives that I can use or any other tips to improving emissions? 

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New plugs, make sure your points are set correctly and timing is spot on, new air filter, route the rocker cover breather down to the chassis and blank the intake pipe where it went in the plenum, fresh fuel and finally just before you take it for test give it an Italian service.;)

Stuart.

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6 hours ago, rwest said:

Thanks Stuart. I've got most of those covered (filter/plugs/timing), but I like the idea for the breather pipe!

Make sure that you won't get caught on this during a physical engine inspection. I run a few cars this way , and it's a great idea to keep the engine feeding on cold air and petrol, but it's totally illegal to bypass  the PCV system for on road cars in Australia.

Also check your enriching lever on the MU is releasing fully.

 

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Hello
each new (old) metering distributor must be set individually on the running machine. Then the emission test is no problem!

greetings
Ralf

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11 hours ago, Mike C said:

Make sure that you won't get caught on this during a physical engine inspection. I run a few cars this way , and it's a great idea to keep the engine feeding on cold air and petrol, but it's totally illegal to bypass  the PCV system for on road cars in Australia.

Also check your enriching lever on the MU is releasing fully.

 

Run it into a catch then ?

Stuart.

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27 minutes ago, stuart said:

Run it into a catch then ?

Stuart.

If there was a physical inspection by the French  you'd have to convince them a catch can or snorkel  was as originally fitted .  Fair chance the inspector couldn't tell the difference between a TR4 and a TR6. 

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22 hours ago, rwest said:

I am trying to get my car through the French "Controle Technique" and the only failure point at the moment is, unsurprisingly, the emissions check.

The car has been sitting around in the UK for the last 3 years, which I would guess is a contributing factor. I have replaced the fuel with nice fresh 98 RON fuel and intend to put around 500 miles on the clock before retesting. I have just fitted a new metering unit which should also improve matters.

The question is - are there any additives that I can use or any other tips to improving emissions? 

Hi, I think you will have your work cut out, when I had mine (1973 PI CR model) tested last year, it also failed miserably on emissions. Elclem fiddled with the timing at his workshop and when we got to the CT station it still failed, luckily our tester was very co-operative and after an hour of fiddle fiddle fiddle, the emissions computer went GREEN and we quickly saved the data, at least when your car finally passes you do not have to worry about it for another 5 years

 

IF MY CAR HAD BEEN 6 MONTHS OLDER IT WOULDN'T HAVE NEEDED AN EMISSIONS TEST

The other big problem with a French CT is finding a chassis number on the car - dont try looking -- they do not exist!!

kc

Edited by kcsun
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3 minutes ago, kcsun said:

The other big problem with a French CT is finding a chassis number on the car - dont try looking -- they do not exist!!

kc

Unless its a Malines built car as they have it on the right hand inner lower suspension bracket box, stamped on top of the rear one.

Stuart.

897865263_MarksTR5086.thumb.jpg.76d4822277a4376f47ffb0d298198f62.jpg

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10 minutes ago, kcsun said:

Thanks Stuart, i will have a look

kc

Its only on Malines built ones, UK built dont have that.

Stuart.

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Now there's a funny counter intuitive thing about the Lucas Pi system , 'cause it relies on manifold vacuum it will tend to run slightly leaner with a not so clean air filter (not blocked, but just not brand new), so it may be worth putting the old filter back for the emissions test and see if that gets a marginal system through.

Cheers Rob 

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I think it should be around 4.5. It is achievable also a leaking exhaust can affect the reading.

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In the US, emissions are tested for HC and CO. My 76 always had issues. After a lot of trial n error, I learned that the HC would spike if there was lean misfire, especially at idle. That means the best spark you can generate and at the proper time. I eventually put in a EDIS system as that had huge spark. As for CO, I added a lot of oxygen in the form of alcohol additive.  The brand in the states is called HEET, comes in a yellow bottle. I added a lot of that to a tank with about 2 gallons in it. Passed emissions and then filled it up to dilute the alcohol. IDK if the PI systems could tolerate that. And last but not least, set the idle at 1000 rpm and set the valves a little loose. Passed every time after that.

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What emmisions regs are they testing to?

Trying to get a PI through tests that were more stringent than those applied in early 1970s UK may be tricky.

If it is just CO they are meauring you could, once you have excluded manifold air leaks that can cause rich running, simply screw the mixture rings to weaken off (having marked them so you can put them back exactly as they were once the test is over)

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3 hours ago, Andy Moltu said:

What emmisions regs are they testing to?

Trying to get a PI through tests that were more stringent than those applied in early 1970s UK may be tricky.

If it is just CO they are meauring you could, once you have excluded manifold air leaks that can cause rich running, simply screw the mixture rings to weaken off (having marked them so you can put them back exactly as they were once the test is over)

Hi Andy, yes I'm fairly sure it is the CO that they're failing me on.

I've just fitted a new KMI refurbished MU to the car, and I'll be putting a few miles on it before I get it retested. That in itself felt like heart surgery to me, so not sure how I'm going to feel about fiddling with the mixture rings. I have the Lucas Red & Green books - but I'll be honest and say that they don't make me feel very much more comfortable. Do you know of any articles that would help an amateur like myself?

Having spent 25 years with Enginuity around to fix things like this for me seems like a distant memory now that I'm living in the South of France, however I do realise that there is a great bunch of people online that are happy to give advice.

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Under the plastic dome there are 3 threaded rings- mark a line down with tippex or paint so you know where they started. Loosen the lower lock ring and screw out half a turn and see if that is enought to weaken it sufficiently Don't forget to put the screws that hold the cap on back in or you will lose vacuum and run very rich. (The cap itself is not important to the fuction of the metering unit)  Then tighten up the lock ring. Once you have passed the test put it all back to where it was. The Lucas PI is a compromise and most times achieving modern emission levels will impact the performanc in real use. You don't drive a 6 at tickover.

It might be worth a call to KMI first as removing the cap will lekely affect the warranty but a friendly ear might work avoid that in the unlikely event that the unit fails in the near future.

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On 3/27/2021 at 10:05 AM, Mike C said:

Make sure that you won't get caught on this during a physical engine inspection. I run a few cars this way , and it's a great idea to keep the engine feeding on cold air and petrol, but it's totally illegal to bypass  the PCV system for on road cars in Australia.

Is the oil breather a PCV for legislative purposes? Mine has only a flame trap in it, which isn't capable of maintaining a positive pressure in the crankcase relative to the plenum. BTW I'm not arguing that the breather doesn't reduce emissions, just asking if it actually qualifies as a PCV...

On 3/27/2021 at 5:18 PM, Schnippel said:

each new (old) metering distributor must be set individually on the running machine. Then the emission test is no problem!

Best advice you'll ever get about the PI ! The PI system may be a compromise, but it's a precise compromise :D. No two of our engines are the same after 50yrs of life, abuse and TLC. You can get close with a reconditioned PI set up to factory specs, but that's suited to an engine out of the factory. Investment in setting up on a rolling road (or building your own calibration rig and installing AFR kit) delivers many smiles. At a cost, sadly.

On 3/28/2021 at 9:33 AM, CK's TR6 said:

As for CO, I added a lot of oxygen in the form of alcohol additive.

Would Toluene (methylbenzene) work as well? It's not an oxygen booster, but it is an octane booster and helps the engine burn more efficiently. It's cheap as well, as it's a paint thinner. Be careful with it though as it's carcinogenic and generally nasty (it is a component of petrol BTW). But a small amount (10%) added to get through the test might be worth trying.

On 3/30/2021 at 8:10 PM, Andy Moltu said:

Loosen the lower lock ring and screw out half a turn and see if that is enought to weaken it sufficiently

If the test is for emissions at idle, then A2 screw is the one to go for. Get the engine warm, and running at idle. Screw out A2 until idle speed maxes, and you have the most efficient mixture. Obviously this will be trial and error, as there may be a vacuum leak when the A2 locking ring is loose, but it's pretty easy. But as Andy says, Tippex beforehand!

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Hi John and Andy

Thanks for your advice - I may be coming back for more info/hand holding later.

My latest problem is that the petrol pump has just decided to lunch itself as well, so now I'm waiting for a replacement from the UK before I can do anything else. This is a warning of what happens when you don't drive a car for 3 years, the petrol additives slowly eat away at the insides of your car :( So far - burst MU diaphragm (replace entire MU), petrol & oil seals on MU drive shaft were brittle and leaking, one of the injector hoses decided to snap, and now the petrol pump. I'll be replacing the petrol filter at the same time. To be fair, the last time I replaced them was about 15 years ago.

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deterioration while standing might be the ethanol oxidising. There are fuel addtives to combat that, widely used for over-wintering lawnmowers.

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re toluene. I doubt it would make a difference as an engine at tick-over is nowhere near detonation, and RON is immaterial.

Another trick might be to lower the fuel pressure at the prv.

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