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I have ongoing problems with the PI system on my TR6. The current fuel system consists of a Bosch pump and a modern diaframe pressure regulator. Earlier this year I found that some of the injectors were leaking, so I replaced them all with a reconditioned set. This appeared to work for a while, but now I can see that at least one of the injectors is spraying continuously even when the engine is not running. My thought was excessive fuel pressure. Is this a likely explanation, or is there something else I should be looking at? Thank you in advance for your help Regards Bruce

I have a 1973 CR with fuel injection and a Lumenition ignition system and K&N air filter. I have noticed that when I am "cruising" at about 50mph or 60 in overdrive i get a slight hesitation/misfire. This is with just a slight pressure on the throttle to hold the speed. If I put my foot down the car pulls like a train with no issues and also accelerates from standstill without any issues. I only run 98 fuel and have filled up quite a few times during the summer but still have the same issue. It has a Bosch pump with the separate paper fuel filter which I have changed. I then changed the spark plugs but still have the same problem. A friend lent me his Magnecor leads, dizzy cap and rotor arm and still the same problem. When I start the car it needs the choke out but I can fully return it after only a mile (it does go fully back). When I came home after a show last weekend (about 60 miles) my wife was in the drive as I turned the car round and she said that it stunk of fuel (running rich?) I have attached photos of the new spark plugs which have now done about 500 miles Any ideas?? kc kc

Good evening wise fórum. Formaly in my 1971 tr6, I could ear petrol coming back from MU INTO the tank , on idle. For No apparent reason it Started to leak along the return pipe to the tank where ruber replaces cooper, even when circlips were set... It looks that I have a strong pressurized fuel return. Try to blow all the way and there is no resistence Petrol cap os original, makes no diference when open Where to look ? Thankyou

Ive always thought my TR6 runs rich with its characteristic exhaust smell and smoke on heavy acceleration. However on my many long runs including to Le Mans I do honestly get good mpg of 30-32. Recently on a spring trip to Devon with the Essex TR group I experienced the same mpg filling up at 225 miles with an indicated 1/4 tank left. I know many TR6 owners wouldn’t dream of letting the tank to such a low level. My Bosch type pump is 15 years old and during one scary experience in France it was still running prior to refilling with 38.5 litres! ( I have witnesses!). Anyway back to my point, under low throttle openings at speed (60-70) the mpg is clearly good but on acceleration the smoke is there and exhaust smell noticeable in the back draught leaving our clothes and hair in need of a clean. I’m happy with engine timing, butterfly set up etc. I’m concluding I need to renew the metering unit as it is 15 years old and 40-50k miles. I’d welcome any thoughts on my experience. I am driving to Malvern from Essex this Friday, so expecting the same issue. Regards Trevor Hughes

Hello all, In the words of Austin Powers, allow myself to introduce, myself: Smooth, handsome and wealthy, with a penchant for exotic cars. Well, that’s quite enough about 007. As for me, I’m a highly mechanically competent privateer with an unhealthy obsession for carbs and extracting every last pony out of vintage cars.* In short, a middle aged man in suburbia, living the dream! I’m currently helping my BIL with the challenges bestowed upon him by his gorgeous TR6 PI running the Lucas Injection system - which I have been learning a lot about of late. Here’s a great read that I’m certain is old hat to the 6-enthusiast. http://www.lucasinjection.com/index.html The car was running beautifully but then began having issues starting and bogging down / fouling plugs / stalling. We identified the MU as the underlying issue which was sent away and rebuilt by an expert. But sadly the garage who fitted it for him haven’t dialled it in on a RR or with a gas analyser. I cannot imagine it’s set up correctly for the car. Frankly I don’t believe they understand it well enough and gave it their best shot. Since getting it back from the garage the car is running very rough, popping through the intake when blipped and slightly reluctant to rev / down on power. Doing the old school test: WOT then turn engine off and into neutral / coast to the side of the road, the plugs look lean to me. I can even smell the leanness - anyone else sad enough to know that smell? So potentially we have two issues of mix and injection timing both being off. If it was on multiple carbs I would say it’s akin to them being out of balance and overly lean. The car is on electronic ignition (no vac) with ROCK SOLID timing which I’ve checked - 17degrees @idle (850-900rpm) and maxing out at 27 @2.5k ish which was only as far as I took it to ensure it was sufficiently advancing. Plugs, leads, coil are all new. Cant recall the plug gaps but they are all even. Vac hose to MU is new, brake booster hose is good and there are no known false air sources / leaks. Butterflies balanced with air-flow meter. We know the car has a stage 3 head (whatever that means) but not sure if the cam is totally stock. So next, I’m going to check the cam profile - using one DTI over the rockers and another I have which confirms TDC through the spark plug hole; it’s a very useful bit of kit. So, now we have the long intro out of the way, please allow me to gain the benefit of your insights / experience: 1. Firstly, does anyone know what the crank damper OD is on these cars? I need to get stick on 360degree marks to be able to properly check the cam profile / LSA / lift / etc with the DTI and a spreadsheet. 2. I read everywhere that the voodoo magic of the MU is not to be touched by mortal hands, otherwise we shall all perish - most horribly!!! So are there any recommended garages in the South East (or even up to the Midlands) whom we trust with good knowledge of dialling in MUs / understand Lucas injection system well? 3. Let’s be controversial - is it really beyond the wit of man to adjust the 3 rings of the MU with an o2 sensor / AFR gauge and get it right? Seriously, I don’t see any magic in the schematics. Except for setting up the correct injection timing, it doesn’t “look” any more involved than setting up triple DCOEs!! Am I missing something? I’d be most grateful for your kind advice / pointers. Thanks in advance, Ali Ps. *My NA Datsun Z on twin 1.75” SUs (with custom needles) is currently doing 245BHP @6.5k and low 13 quarter miles; now tell me “them SUs just won’t flow” ;)! Oh and with two TRs in the family we regularly talk about my Jap-*rap!! So feel free to have a good dig, my skin has been somewhat thickened!

Hi All Getting well on with my resto now and as most things seem to work I’m trying the first engine start in my ownership and for well over a decade, but I can’t get it to fire and so I need a bit of advice. So it’s got a rebuilt engine (by me) as well as new electrics and the pump, starter and ignition all seem to work. All Pi gear was refurbed properly, by Neil F, and is completely standard so that bit should be good. Now after messing around with quite a few niggly issues, ignition and leaks, all of those seem to be sorted and I have a sparking ignition and leak free fuel system. I’ve cranked the engine over for a while (without plugs) and got oil pressure. I won’t say how much as you might all laugh, but if someone can give me an idea of what the gauge might show on just a starter motor crank that would be great. I might then be happy or not as the case may be, lol. I’ve left the Ign on so the pump is running a good while a good to try to prime the system with fuel and get rid of the air, but are there any tricks to whether that has worked or not? So i connected everything up and attempted to start it several times with no joy. I tested for a spark and thats ok but after the jam jar test no fuel at the injectors. So the questions that occur to me are have I left the fuel pump running enough to get enough fuel in the MU to get to the injectors? So can I just leave it pumping on the ignition or do I have to crank it over for ages (how long?) or will that damage the pump? Or after reading some other posts on the forum do I have another issue? One post says if the injector pipes are not pulsing (they aren’t) the plastic dog driver could be broken? Is that correct and how can I tell unless I pull the MU. So a list of stuff I should I check would be fab. Cheers Keith

Hi Had a run on problem with my 1974 PI (owned 34years) last year replaced my Beru Ultra X UX56 with new UX56 plugs bought from the Green Spark Plug company. The prevoius plugs I bought off ebay & suspected they were cheap copies. The problem I had was a slight run on which I had never experienced before. Engine would turn a few times then clonk out. But with the new UX56 plugs the run on was greatley reduced. Still occurs very ocassionaly. The car runs very well with plenty of power & on a motorway runs & returns 30mpg The car has been on a rolling road at Wilshers Garage Peter Baldwin who trained as an apprentice on Triumph PI cars. This was in 2016 Feb Peter recalibrated the metering unit on the rollers & got 180 bhp at 4000rpm The rolling road part of the garage has now closed. But still get a little run on occasionally so guess something still amiss. Only use 98 petrol mainly BP or Shell. Nothing else changed on the car. Electronic points in the distributor since engine rebuild by manvers & covered 50K miles since 2005 Alec