Paul Hill Posted March 24 Report Share Posted March 24 (edited) Great video with Ian Tyrrell on YouTube lauding how good the PI system is. Well worth a watch Edited March 25 by Paul Hill Quote Link to post Share on other sites
CharlieBubbles Posted March 25 Report Share Posted March 25 Terrific thanks Paul! (right colour too…) Quote Link to post Share on other sites
Ernest Posted March 25 Report Share Posted March 25 Thanks Paul - lovely and informative video Best Wishes Ernest Quote Link to post Share on other sites
Macleesh Posted March 25 Report Share Posted March 25 Quite enjoyed this apart from when he pulled an injector out whilst the car was running. Personally I think that's a bit ill advised. Quote Link to post Share on other sites
Paul Hill Posted March 25 Author Report Share Posted March 25 I thought that too, but if anyone knows what it’s about it’s him, he is a genius so I will forgive him Quote Link to post Share on other sites
Mk2 Chopper Posted March 26 Report Share Posted March 26 Enjoyable video, thanks for posting it. I've done the exact same adjustment on my metering unit, I had a colortune fitted but it was the sound that gave me the most accurate setting. Gareth Quote Link to post Share on other sites
Macleesh Posted March 26 Report Share Posted March 26 Interested in doing this myself, how do you undo the lock ring? Is a special tool required? Quote Link to post Share on other sites
Mk2 Chopper Posted March 26 Report Share Posted March 26 I seem to remember, just tapping it gently with a screwdriver and hammer will loosen it. Best to mark the position of the cylinders before you do so that at the very least you can put it back where it was. I went through all the others things first that can affect mixture at the MU, namely the vacuum amount. Throttle plates closed and balanced, air filter clean or new, tappets adjusted correctly. I put a gauge on the vacuum take off to measure the amount. Making sure you have no leaks from the hoses, diaphragm etc. Good idea to make sure the ignition side is working well too before finally tweaking the MU. Gareth Quote Link to post Share on other sites
mleadbeater Posted March 26 Report Share Posted March 26 Interesting video, if a little brief on the actual workings and adjustments to the PI unit. I am still struggling with why his car revs cleanly, without bogging, when he blipped the throttle, and surprised that weakening the mixture didn’t introduce bogging. Advice from the forum suggests running rich is the cure for bogging, on my ‘6 the large spring is fully screwed down, yet still it bogs on blipping initial acceleration. Mike Quote Link to post Share on other sites
Mk2 Chopper Posted March 26 Report Share Posted March 26 When I adjusted mine, the colortune wanted a certain setting to get the flame blue, but listening by ear, it didn't sound as good, when I adjusted by sound the colortune was starting to go more orange, but it ran better. So I'm guessing he wasn't far out to begin with, but it made some difference to how the car felt. My problem was being over rich and sooting up the plugs and exhaust. I don't get any noticeable bogging. Maybe have a play with it, mark where you start from and try adjusting things, assuming you've done the other checks first I suggested, plus I forgot to mention I checked the fuel pressure at the MU too. Gareth Quote Link to post Share on other sites
mrehke Posted March 26 Report Share Posted March 26 Neil Ferguson near to Stafford is the man to adjust the MU - he worked for Lucas PI Department and has the Lucas Test Bench equipment for setting the MU and other components...he is also a good bloke! Quote Link to post Share on other sites
michaelfinnis Posted March 26 Report Share Posted March 26 In theory the mu should be set up on the bench, using a flow test rig. The triumph workshop manual actually cautions that the adjustments should not be touched. On the other hand, logically you would think that although the bench rig gives the correct basic settings the mixture would ideally be tweaked to suit each individual engine? Quote Link to post Share on other sites
Paul Hill Posted March 26 Author Report Share Posted March 26 2 hours ago, mrehke said: Neil Ferguson near to Stafford is the man to adjust the MU - he worked for Lucas PI Department and has the Lucas Test Bench equipment for setting the MU and other components...he is also a good bloke! Neil is indeed the man he is only 20mins from me, he did my MU a couple of years ago while I looked on Quote Link to post Share on other sites
DRD Posted March 27 Report Share Posted March 27 21 hours ago, Mk2 Chopper said: When I adjusted mine, the colortune wanted a certain setting to get the flame blue, but listening by ear, it didn't sound as good, when I adjusted by sound the colortune was starting to go more orange, but it ran better. So I'm guessing he wasn't far out to begin with, but it made some difference to how the car felt. My problem was being over rich and sooting up the plugs and exhaust. I don't get any noticeable bogging. Maybe have a play with it, mark where you start from and try adjusting things, assuming you've done the other checks first I suggested, plus I forgot to mention I checked the fuel pressure at the MU too. Gareth Using a Colourtune will result in a mixture that is too weak - it needs to be between 12-13:1. Quote Link to post Share on other sites
Tim D. Posted March 28 Report Share Posted March 28 I played around with my MU a fair bit when I ran PI. I did the work with an air fuel ratio meter connected recording data while driving a standard circuit with different driving conditions. My advice is definitely get rhe MU baselines by someone like Neil first. This gets you 90% of the way, in some cases, depending on the state of the engine, all the way there. Then depending on your skill and whether you have and Afr you can do the last 10% yourself. I got kine to a state where bogging was non-existent but I was also not running as rich as the standard setup making it less smelly and more fuel efficient. But it was a very careful process to get there. Regarding colour tune. I think it may have been said before, but it seems a yellow tinge is good for modern fuels. But in the end it will only tell you about mixture at idle of course. Tim Quote Link to post Share on other sites
Andy Moltu Posted March 28 Report Share Posted March 28 On 3/25/2024 at 5:50 PM, Macleesh said: Quite enjoyed this apart from when he pulled an injector out whilst the car was running. Personally I think that's a bit ill advised. It’s safe enough if done with care. Needs a spark or a flame to ignite the petrol so carefully removing it and pointing at a jam jar, or simply aiming it at the injector port so any fuel sprayed goes where it would have gone anyway will have negligible risks attached. Quote Link to post Share on other sites
Keith66 Posted March 28 Report Share Posted March 28 On 3/26/2024 at 3:49 PM, mrehke said: Neil Ferguson near to Stafford is the man to adjust the MU - he worked for Lucas PI Department and has the Lucas Test Bench equipment for setting the MU and other components...he is also a good bloke! Neil is indeed the Pi man and i'm lucky being about half hour away As said he worked as a Lucas engineer for 20 years or so before it all went under and purchased lots of the test equpment they used. He refurbs all of the Pi gear and supplies many of the parts suppliers and as others have said is very helpful, though he can occasionaly be hard to get hold of, so patience. No connection other than he refurbed all my Pi gear to a great standard and it was running well until my fuel tank rust issue blocked the filter and caused havock. Cheers Keith Quote Link to post Share on other sites
J.C. Posted March 28 Report Share Posted March 28 Neil Ferguson refurbished and calibrated my MU and it have been really pleased with the work. Amazing workshop if you get the chance to see it and a really nice bloke too, would not hesitate to use him again. Quote Link to post Share on other sites
astontr6 Posted April 1 Report Share Posted April 1 On 3/28/2024 at 10:53 AM, Andy Moltu said: It’s safe enough if done with care. Needs a spark or a flame to ignite the petrol so carefully removing it and pointing at a jam jar, or simply aiming it at the injector port so any fuel sprayed goes where it would have gone anyway will have negligible risks attached. +1 Bruce Quote Link to post Share on other sites
Neil Ferguson Posted April 2 Report Share Posted April 2 Regarding my workshop I've actually had a bit of a tidy up and can fit cars in again (wife can't believe I've done it) Quote Link to post Share on other sites
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