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Metering unit expectations


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Hi Peter,

Thanks for the video - very clear. You're looking at it unassembled, and that's the problem. If you assemble the MU to the CU you will find the spring pushes the rotor towards the distributor, against the thrust plate. You can push it the other way, but it returns under spring pressure when you stop pushing. So the end float is taken up by the spring. In practice, there's nothing to exert that force (away from the distributor). From your video, the ports appear aligned when the rotor is in the position the spring will hold it in. I can't see any harm in putting in a shim, but nor can I see the need.

Cheers,

John 

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2 hours ago, peter wilson said:

One last quandrary - normally the various official Triumph publications state MU timing to be opening up  with a full hole being allowable. Eg this is from  the Fault Cards.

image.png.8c41c356cbb7bbd0ee6e2100e6cc2cbb.png

 

My latest installation gave me completely open hole (cyl 6) at TDC which I had been taking as allowable (Above bottom left situation). Now in the latest info the blue book there is conflicting information.

Petrol Injection System Fault Diagnosis.  image.png.2737597cbdaf850375d73dba09d23106.png

 

Which document would you trust on this??  Cheers Peter

I've always followed the Brown Book, which shows acceptable sleeve port sector openings at the top (towards the block). Even the sleeve port almost covering the rotor port is OK as long as the opening sector is at the top.

With regard to No.2 not bleeding, you obviously would have checked the injector line is not blocked? Maybe remove the line and blow CA in the direction of flow in case somethings wedging closed  with the fuel flow.

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On 9/23/2020 at 9:42 PM, peter wilson said:

Hello Matt, I am also in AKL/Whangarei NZ with a TR6 with MU problems so may be able to help. Firstly are you in the NZ TR Register as the Technical chap Ken is absolutely brilliant at helping and very experienced (with around 6 TRs of his own to maintain), so can I suggest you contact him for help locally. secondly and after Kens help with my two MU's active plus spare, I believe that these should be setup by the OH facility which perforce must have a test bench for that task, and after this the unit should only require installation, timing to the engine and no other adjustments should be needed. This assumes an engine pulling good vacuum which mine wasn't.  As you found with the screws leaking (mine did likewise) these cars a a bugger if the vacuum is not there as they go to full rich and quickly wet plugs - lose ignition and its all over really. I have a permanently installed vacuum gauge now, and after head overhaul with new valves guides rockers shaft etc I now have good vacuum close to 9in Hg. The other problem area in my experience is the 6 butterflies and multiple linkages making it very hard to set up. I am looking to install an improved mechanism in due course.  Let me know prmwilsonatgmaildotcom if I can help locally.  Cheers Peter   JohnC thanks very much for the link to Peter Bower - I now have someone to send my MUs. Great.

 

PS does anyone out there know how much end float you should have on the rotating sleeve of the MU - un installed and push/pull on the drive end - I am getting quite a few mm yet cannot see how this is normally controlled. Ok normally the metering end is pushing back but that doesn't seem a satisfactory result. Thanks in advance Gents.

Thanks Peter, absolutely a member of the AKL crowd & agreed, it seems this vacuum issue will be the one (hopefully...)

Butterflies and throttle linkage should be ok as I've changed the CR sytem (that was worn) to a Racetorations underslung version with rose joint adjusters

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Many thanks JohnC, MikeC and Matttnz. I finally can get my head around the spring force being applied to the moving end stop and then into the pressurised fuel and so able to transfer force across to the sleeve and cause it to travel to reduce the end float to effectively zero.  The problem I had was how the sleeve would stay "loaded" like this when the fuel requirement was reduced to less than maximum - in which case the  variable end stop would be withdrawn partially and initially I thought that would give the sleeve a chance to move but I suppose there is always enough spring force to keep it correctly in place. Nevertheless it seems a strange way of controlling end float but I suppose there must be a reason for that design "feature".  BTW I have had a message from Bowerpower overnight to the effect that they are no longer working with Lucas PI units - sadly.  Best facility for an exchange MU in the UK would be??  Thanks again Gents - happy motoring.  Regards Peter

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Hello MikeC, Thanks I will move my MU timing one tooth on the basis of this. The fuel line is new and also is transparent so no blockage problem. I run the car again today with the No2 injector line disconnected completely and there is zero fuel delivery. Yet it has a brand new Banjo Bolt having cost 78$ plus GST... So tomorrow the MU comes out again..Mutter mutter..  

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I have a Brown Bible, instead of a Blue Book, but maybe it is as authoritative.     It has TWO separate instruction pages:

Page 1/ "Up to engine CP 77609E"  the hole should be in any position up to and including full view through the port -

Page 2/ "From Engine No.CR1E" "Turn ... until a full rotor hole is visble through No.6 outlet.    Continue to turn until the rotor hole just disappears from view, then rotate the gear one extra tooth"  -

So it depends on what you have and what you want.

John

Edited by john.r.davies
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""BTW I have had a message from Bowerpower overnight to the effect that they are no longer working with Lucas PI units"- for me that is bad news, I had a lot of trouble getting my PI equipment serviced in Australia before I came across Peter Bower. And a TR6 with a malfunctioning PI system is a dog of a car, far worse that an out of tune carburetted car. 

I'm interested in the recommendations you receive for current UK Lucas specialists.

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1 hour ago, peter wilson said:

BTW I have had a message from Bowerpower overnight to the effect that they are no longer working with Lucas PI units

That's disappointing and surprising. I was talking to Peter Bower only a month ago about getting him to do some work on my PI unit.

BTW if you need any seals, o-rings, diaphragms etc for the PI, David Clark sells them. Really! I bought a set a fortnight ago.

John

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58 minutes ago, JohnC said:

 

That's disappointing and surprising. I was talking to Peter Bower only a month ago about getting him to do some work on my PI unit.

BTW if you need any seals, o-rings, diaphragms etc for the PI, David Clark sells them. Really! I bought a set a fortnight ago.

John

Thanks John. I've had o rings and diaphragms, supposedly of Viton, airfreighted to me from overseas  at great cost in the past and they've lasted less than an hour on Australian high octane unleaded. One of the things I liked about Peter was that he had his own components made of quality material. I hope he keeps working on TR's but I've added David to my suppliers list-thanks.   

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Hi guys - just for completeness here is the reply I got from Bowerpower so it seems fairly definitive. I was very alarmed to read your post MikeC re new orings etc failing with Australian fuel as I have orings here that have done very little time and seem to be failing. These things are so expensive to buy you would expect you are buying quality.. Thanks for your alternative supplier thanks JohnC. Cheers Peter.

 

Hello Peter,

Thank you for your message.

I’m hearing all your saying with the troubles / setbacks you’ve had with your cars. Unfortunately  we can’t help you. Our business

Has gone in another direction with what we restore.

All I know of is a man in the UK who restores these Triumphs components.

Sorry I can’t offer any further help. All the best with your endeavours.

Kind Regards,

Fleur Rogers

Business Director | Fuel Systems Technician

                               

ABN: 47 264 243 771           

A: 6/280 New Line Road Dural. NSW. 2158

T: (02) 9651 5509 | E: admin@bowerpower.com.au

W: bowerpower.com.au

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1 hour ago, peter wilson said:

 

Hi guys - just for completeness here is the reply I got from Bowerpower so it seems fairly definitive. I was very alarmed to read your post MikeC re new orings etc failing with Australian fuel as I have orings here that have done very little time and seem to be failing. These things are so expensive to buy you would expect you are buying quality.. Thanks for your alternative supplier thanks JohnC. Cheers Peter.

 

Hello Peter,

Thank you for your message.

I’m hearing all your saying with the troubles / setbacks you’ve had with your cars. Unfortunately  we can’t help you. Our business

Has gone in another direction with what we restore.

All I know of is a man in the UK who restores these Triumphs components.

Sorry I can’t offer any further help. All the best with your endeavours.

Kind Regards,

Fleur Rogers

Business Director | Fuel Systems Technician

                               

ABN: 47 264 243 771           

A: 6/280 New Line Road Dural. NSW. 2158

T: (02) 9651 5509 | E: admin@bowerpower.com.au

W: bowerpower.com.au

Thanks for the info Peter. I now source Viton  o-rings from an industrial bearing supplier in Australia- I use CBC (who I believe are Saeco Wilson in NZ). The diaphragms are more of a concern, the major TR suppliers don't seem to be able to differentiate between nitrile and Viton, and on our fuel the life of many nitrile components is measured in single digit hours. I understand David Clark supplied parts to Bowerpower, so hopefully  I have those components covered. Now I just need to find someone with a Lucas test & calibration rig-and that knows how to use it.

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Cleaned (ultrasonic bath with valve open) and refitted my previous banjo bolt as the new 78$ bolt would not pass fuel at all (like me at 67).  Now I get flow and bled the injector but there is still a regular air bubble that appears at the MU banjo connection and works its way along the tube (mine are transparent which has proved a bonus so far). Any ideas where air could find its way to just that cylinder. If the (new) injector feed pipe was somehow not sealing on the barb of the banjo surely that would leak fuel which it isn't rather than draw in air. And if it is coming from the MU why only that cylinder... Baffling..   My only real thought is to swap with my spare MU but the metering section is set up for race work and thus too much fuel for this car -- so would have to mix the two up and a bit reluctant to do that.  For sure I will send one or even both away for exchange but unsure which specialist to opt for. Obviously they will be going back to the old country!  Any suggestions appreciated, thanks. Cheers Peter  

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Hello JohnC, Yes those diaphragms are brutally expensive and then to have them fail is bad news. I have just had to fit one and will be "interested" to see how that lasts, as it came from a mainstream Triumph specialist in Auckland and I presume originally from Moss or Rimmers.  I do go to Saeco for seals and o-rings and having had a new seal for the pedestal leak with just a few hours, the girl there suggested that I should be using a high pressure seal and sure enough that has held up well so far. RSM015024007HNC which is a 15 x 24 x 7 high pressure oil seal. Just FYI. Cheers Peter

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1 hour ago, peter wilson said:

Cleaned (ultrasonic bath with valve open) and refitted my previous banjo bolt as the new 78$ bolt would not pass fuel at all (like me at 67).  Now I get flow and bled the injector but there is still a regular air bubble that appears at the MU banjo connection and works its way along the tube (mine are transparent which has proved a bonus so far). Any ideas where air could find its way to just that cylinder. If the (new) injector feed pipe was somehow not sealing on the barb of the banjo surely that would leak fuel which it isn't rather than draw in air. And if it is coming from the MU why only that cylinder... Baffling..   My only real thought is to swap with my spare MU but the metering section is set up for race work and thus too much fuel for this car -- so would have to mix the two up and a bit reluctant to do that.  For sure I will send one or even both away for exchange but unsure which specialist to opt for. Obviously they will be going back to the old country!  Any suggestions appreciated, thanks. Cheers Peter  

As I see it the injection system is under a reasonable  pressure from the pump to the injector, unless some component goes under negative pressure due to a fault , air can't get in. If the car's in a position to run, try a high load run to try and clear out  any residual trapped air .

Do you fit your nylon injector lines cold? It's harder but Lucas have recommended it over the years for their PI TR and saloon engines.

I'd contact David Clarke  to see if you can get a Viton diaphragm.  Last one I got from the brothers was definitely nitrile. It swelled up with our fuel and leaked around the shaft  while I had lunch. Pity the airfreight doubled its cost plus the effort in getting the MU out, replacing  the diaphragm then reinstalling it. Peter Bower had a source of Viton diaphragms- that's one of the reasons I subsequently  bundled up the MU & injectors and told him to fix the lot.  

  

Edited by Mike C
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21 hours ago, Mike C said:

""BTW I have had a message from Bowerpower overnight to the effect that they are no longer working with Lucas PI units"- for me that is bad news, I had a lot of trouble getting my PI equipment serviced in Australia before I came across Peter Bower. And a TR6 with a malfunctioning PI system is a dog of a car, far worse that an out of tune carburetted car. 

I'm interested in the recommendations you receive for current UK Lucas specialists.

Hi Mike,

For me one of the key original Lucas specialists is KMI. They started in business about 40 years ago re-conning Lucas and Bosch PI parts and were the originators of Bosch  pump conversions. Some members of their staff worked for Lucas CAV where a lot of the Lucas PI was made. They also supply a Sprint calibrated M/U for Newman PH2 cam or SAH type 357 cam or BLs' S2 cam. This was part of SAHs' conversion to increase the 125 DIN TRs' back to a genuine 150bhp.

Bruce. 

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43 minutes ago, astontr6 said:

Hi Mike,

For me one of the key original Lucas specialists is KMI. They started in business about 40 years ago re-conning Lucas and Bosch PI parts and were the originators of Bosch  pump conversions. Some members of their staff worked for Lucas CAV where a lot of the Lucas PI was made. They also supply a Sprint calibrated M/U for Newman PH2 cam or SAH type 357 cam or BLs' S2 cam. This was part of SAHs' conversion to increase the 125 DIN TRs' back to a genuine 150bhp.

Bruce. 

Thanks Bruce. KMI were on my list before I found Bowerpower in Australia. If Peter Bower has exited the TR6 market I'll be looking at them. Looking at their website I'd accept they're pretty good technically, do you have any experience with how they perform in terms of time?

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1 hour ago, Mike C said:

As I see it the injection system is under a reasonable  pressure from the pump to the injector, unless some component goes under negative pressure due to a fault , air can't get in.

As the system cools down after a run I believe you get the negative pressure. In my job I've found out the hard way about uni-directional leaks - liquid can't get out but air gets in. I believe this is why I have to crank for a time before fuel gets through. (I too have pre-ethanol seals in parts of my PI system.)

Cheers, Richard

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All this talk about green, blue, brown or whatever books is unneccessary. There is a printing mistake in the Workshop manuel Section 19.35.01 It shows the rotor positions. Unfortunately the bit shown as black is in reality white and the parts shown as white are in reality black. QED

Next time when you look down the holes and read the instruction this will make sense.

Otherwise said a waxing moon is correct. Not a waning moon.

Don't forget a car will still run!!!!!! even with a metering unit 180° out of place.

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2 hours ago, Mike C said:

Thanks Bruce. KMI were on my list before I found Bowerpower in Australia. If Peter Bower has exited the TR6 market I'll be looking at them. Looking at their website I'd accept they're pretty good technically, do you have any experience with how they perform in terms of time?

Hi Mike,

I am using their Sprint M/U, 6 of their re-con injectors and one of their new PRVs' which is the same design as the original Lucas one. These were all installed 4 years ago when my engine was rebuilt after 44 years of use. The O rings were starting to break up, I suspect that they were nitrile compound as they had lasted 30 years from when my system was last refurbished! My 1980s' Bosch pump was still going strong and was supplied by them as I was one of their original customers for their conversion.

Bruce. 

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1 hour ago, astontr6 said:

Hi Mike,

I am using their Sprint M/U, 6 of their re-con injectors and one of their new PRVs' which is the same design as the original Lucas one. These were all installed 4 years ago when my engine was rebuilt after 44 years of use. The O rings were starting to break up, I suspect that they were nitrile compound as they had lasted 30 years from when my system was last refurbished! My 1980s' Bosch pump was still going strong and was supplied by them as I was one of their original customers for their conversion.

Bruce. 

Hi Bruce, 

You were obviously happy with their service- the work was completed on time? One of my fears is sending my MU off somewhere to be refurbished and it just disappears for months with no response from the repairer.

I have noticed past concerns on the forum  about this happening with some UK specialist Lucas  repair shops.

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1 hour ago, Mike C said:

Hi Bruce, 

You were obviously happy with their service- the work was completed on time? One of my fears is sending my MU off somewhere to be refurbished and it just disappears for months with no response from the repairer.

I have noticed past concerns on the forum  about this happening with some UK specialist Lucas  repair shops.

I do not know what system Steve would use in your case and how he ships for Export, I would hope he uses DHL or Fedex as they have full traceability. If the company you work for has an account with either? Find out if you can use their account number? As this can save you a lot of money! I will give him a bell on Monday for you. I know that his M/Us' are done on an exchange basis along with his injectors and sometimes PRVs'. He may want your M/U before he ships? But he prefers to supply new PRVs' because of the problem with harmonic hammering. He refused to supply me with a re-con PRV and I had to buy a new one, because he knew that I was using a Bosch pump?  I have had no trouble with any of the parts he has supplied me.

Bruce.

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7 hours ago, astontr6 said:

I do not know what system Steve would use in your case and how he ships for Export, I would hope he uses DHL or Fedex as they have full traceability. If the company you work for has an account with either? Find out if you can use their account number? As this can save you a lot of money! I will give him a bell on Monday for you. I know that his M/Us' are done on an exchange basis along with his injectors and sometimes PRVs'. He may want your M/U before he ships? But he prefers to supply new PRVs' because of the problem with harmonic hammering. He refused to supply me with a re-con PRV and I had to buy a new one, because he knew that I was using a Bosch pump?  I have had no trouble with any of the parts he has supplied me.

Bruce.

Thanks Bruce. With  the local Lucas TR expert gone I'll need the name of another competent repair shop. A TR6 with a malfunctioning PI system is not worth owning .

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Many thanks everyone - lots of good info. MikeC I did fit the new fuel lines cold , with a block of teak made up exactly as Triumph specify. However the comment from you Spit_2.5PI makes me think perhaps I do have a one way air in no fuel escaping leak. Cant explain why but perhaps as you say there is a momentary negative pressure pulse - fluid flow is a funny business for the unwary as I used to find trying to get water reticulated around a rural property. Sometimes downhill isnt enough. So will make another fuel line to No 2 and exchange that and refit / test. Cheers all.

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6 hours ago, peter wilson said:

Many thanks everyone - lots of good info. MikeC I did fit the new fuel lines cold , with a block of teak made up exactly as Triumph specify. However the comment from you Spit_2.5PI makes me think perhaps I do have a one way air in no fuel escaping leak. Cant explain why but perhaps as you say there is a momentary negative pressure pulse - fluid flow is a funny business for the unwary as I used to find trying to get water reticulated around a rural property. Sometimes downhill isnt enough. So will make another fuel line to No 2 and exchange that and refit / test. Cheers all.

Maybe test the  injector line fitted to the MU but not fitted to the  injector. If there's nothing on the end I can't see how you would get a negative pressure in the line at the kind of flows we're looking at.

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