John L Posted January 19, 2007 Report Share Posted January 19, 2007 Hi I have just bought a TR5 and so am new to the Forum I have been using an Innovate wide band oxygen sensor on my other carburettor cars and wonder if it will be possible to use this on the TR. Its not running that bad, but I would like to make sure that its correct. Will it be possible to make adjustments to the meter unit to improve the co. I would also like to make sure the injectors are working correctly, I understand that these can weep a bit from the o ring inside, is it easy to dismantle these and change the o ring? I have the pressure test equipment to do it. Your help would be much appreciated. Regards John Quote Link to post Share on other sites
Richard Crawley Posted January 19, 2007 Report Share Posted January 19, 2007 Hi John & welcome to the forum; there is so much stuff about this topic on the forum already, the first thing you should do is to have a good read back through the archive posts. Some if not all of your questions will be answered but come back with any specific questions you may have. If it's running well at the moment, I would advise against twiddling with the M/U until you have a better understanding of what’s going on -- & even then, for the majority, I would advise against it as you will probably only make things worse without a calibration unit or setting up on a rolling road. Quote Link to post Share on other sites
RalphC Posted February 24, 2007 Report Share Posted February 24, 2007 John, I had my mu set up on a rolling road 20k miles ago and now fuel consumption has got pretty bad and its very obviously running richer than it needs. I wasn't that happy with the rolling road setup in the first place so I'm going to have a go adjusting it myself. I've just got the Innovate LM-1 kit and I've made myself some tools to get to the adjusters easily. I haven't got going yet but I'll let you know how I get on if you're interested. Ralph Quote Link to post Share on other sites
Richard Crawley Posted February 24, 2007 Report Share Posted February 24, 2007 (edited) Hi RalphC & welcome to the forum. 20K is very typical for a Lucas PI metering unit to stay on song, what are you down to now; 14-16 MPG or worse? Don’t confuse the Lucas with a modern PI set up, it was designed in the 1950’s (for Maserati I think) & is purely mechanical. There are some bench re-calibrating procedures you can do successfully on the MU datum track that will help bring the unit back in line but it is almost impossible to do a proper job without the proper calibration equipment or a session on a RR. John’s is a pretty old post & it’s disappointing that he didn’t come back for further advice & I reiterate the advice in my initial post to him; I’ve no idea what the ‘Innovate LM-1’ kit is but I wish you the very best of luck with it! Edited February 25, 2007 by Richard Crawley Quote Link to post Share on other sites
John L Posted February 26, 2007 Author Report Share Posted February 26, 2007 I have had some good success with the Inovate, its a wide band CO meter. It will also log up to about 40 mins of driving. I was able to do a little adjustment to the largest nut under the top hat, by screwing it out less than than a quarter of a turn, but this screw will alter the fueling right thru all the range. I also noted that the 2 screws that hold the top hat on, can cause a vacuum leak, so put some silicone on these screws. I havent had time yet to do a complete run and log the details, but it does now run I feel better, it was about 8% at idle, I have now got it to about 3.5%, I didnt take any mileage consumption figures. One other question I do have, I havent found on any document yet the position of the injection pipes onto the MU, can anybody help please. Regards John Quote Link to post Share on other sites
JohnC Posted February 27, 2007 Report Share Posted February 27, 2007 This should help: Lucas Mk II Injection Manual Cheers, John Quote Link to post Share on other sites
heliguy Posted February 28, 2007 Report Share Posted February 28, 2007 As I am an ocean away from a rolling road, I am most interested in how you got along with the 02 sensor for setting up the MU. Has any one had any luck setting one up with the measurements? And when the car is on a rollling road, just exactly what is it that is being set up? Do they adjust for mixture throughout the RPM band? When they are done with the car, is there a print out as to what has happened at what RPM? Thanks in advance for letting me pick your collective brains.... Mitch Quote Link to post Share on other sites
John L Posted March 1, 2007 Author Report Share Posted March 1, 2007 Heliguy The Innovate tool is great I have used it a lot for other carburettor cars, the co sensor fits in the end of the exhaust pipe, and it gives you the co reading at all engine speeds, I have added the rpm kit to it as well. This also allows adding in pot position, temp, and any other things you want to record. You can also drive with it so you can then read the co at all levels, download to a computer and see all the info. www.innovatemotorsports.com I have certainly improved the idle settings, and will work later when the weather is better to do the whole range. It doesnt seem to be that difficult. Hope that helps? Regards John Quote Link to post Share on other sites
heliguy Posted March 2, 2007 Report Share Posted March 2, 2007 Yes, thanks for the info John. Although my car is still at least a year away from seeing the road, its nice to be able to get this type of info. i know i can have my MU calibrated to "standard" on a test bench, but i think it really needs to be optimized to the car, the type of fuel, the type of driving etc you are going to do. I believe that is why these "rolling road" sessions seem to work out well for most people, but then you need someone who can interpret the data, and adjust the MU accordingly. Keep us informed as to how it works out. cheers, Mitch Quote Link to post Share on other sites
jonlar Posted March 2, 2007 Report Share Posted March 2, 2007 Hi Mitch, to get the best from a PI, the MU needs to be calibrated to the state of tune on the particular car, the relationship between the different cam profiles is what can really make the difference - hence the need for RR. Quote Link to post Share on other sites
jean Posted March 2, 2007 Report Share Posted March 2, 2007 Right Jonlar, the setting on a rolling road also allows the engine to be set under load what is very important. Your engine will have to fight against a giant brake Quote Link to post Share on other sites
heliguy Posted March 3, 2007 Report Share Posted March 3, 2007 It would be nice to know what exactly "they" are doing when it is adjusted on a rolling road. I guess the operator must have a good idea of what to do, or do you get a print out of what HP or fuel flow your MU generated at a particular RPM, and it is now up to you, the owner to take the cap off and make the adjustments? cheers, Mitch Quote Link to post Share on other sites
Richard Crawley Posted March 3, 2007 Report Share Posted March 3, 2007 (edited) It would be nice to know what exactly "they" are doing when it is adjusted on a rolling road. I guess the operator must have a good idea of what to do, or do you get a print out of what HP or fuel flow your MU generated at a particular RPM, and it is now up to you, the owner to take the cap off and make the adjustments? No no no; that's the whole point of putting it on a RR! The operator makes adjustments to the M/U on the fly under various throttle & load conditions. This is something you’re unlikely to be able to successfully achieve by fiddling with the thing on the drive even if you do have an O2 sensor shoved up the exhaust; all this will do is give you readings under off load conditions, not much use really! One of the reasons the PI gained such a bad reputation years ago was that home & even professional mechanics more used to carbs didn’t understand how it worked & it was uneducated ‘fiddling’ that produced 90% of the problems & complaints of heavy fuel consumption! Edited March 3, 2007 by Richard Crawley Quote Link to post Share on other sites
k_raven_smith Posted March 3, 2007 Report Share Posted March 3, 2007 Hi John, We can test and recalibrate your metering unit, and reset back to manufaturers specification, and advise on general condition of the unit. We can also test and repair the rest of the components of the PI system. Katie Quote Link to post Share on other sites
heliguy Posted March 3, 2007 Report Share Posted March 3, 2007 Thanks for the replies gents, but it seems my point is still being missed here. I do understand that fiddling with it is not going to get me to where i want to go, and i do understand that to be set correctly for my car,with my manifold depression, and the type of petrol i use,it needs to be set on a rolling road. I have access to a dyno at one of the schools here ( shop instructor is a member of the local MG club) What i am trying to ascertain is how does the operator adjust the MU? I have the figures and drawings and graphs from the lucas manual, but trying to put that into "real time" , well, im just not grasping it. Sounds like it comes down to the operators experience with adjusting a PI system on a dyno? There must be a few RR operators that are known for their skill in adjusting PI systems? Should i talk to one of these operators so my MU can be adjusted, or would I be happy, just having it set to "factory specs" ( I think I allready know the answer ) The collective wisdom of this forum has helped me immensly allready, I hope you dont think I am trying to re-invent the wheel here, just want to get the best out of my PI system... Thanks again, Mitch Quote Link to post Share on other sites
heliguy Posted March 3, 2007 Report Share Posted March 3, 2007 Alec, That would be great! If you get a chance, could you ask him if it would be allright if I E mailed him with my questions? I will E mail Revingtons as well, and mention this fellows name and see if he would be interested in letting me pick his brain! Thanks so much, Mitch Quote Link to post Share on other sites
Richard Crawley Posted March 3, 2007 Report Share Posted March 3, 2007 Should i talk to one of these operators so my MU can be adjusted, or would I be happy, just having it set to "factory specs" ( I think I allready know the answer ) Mitch If your engine is factory spec. then you will gain little (if anything) by having anything other than a standard, recon M/U from one of the trusted suppliers. You can tune the engine to a fairly high degree but there will always be consequences, it really depends on what you personally want from the car & then you will need a RR session to set it up properly! My engine has a stage 2 head with Phoenix extractor but runs the standard rear box, original CP cam (which is actually very good), dizzy & ignition settings. I purposely limited the state of tune as I didn’t want a snarling, spitting beast that would attract attention & require specialist tuning but it has given me a very noticeable improvement, can still surprise boom box hot hatches but without sacrificing tractability. The car has not yet been on a RR; the guys that did the work on my engine were able to supply a suitably set up M/U from Prestige just by talking to Malcolm over the phone. The state of tune I have is well recognized & he knew exactly what to changes to make when the unit was set up on the flow rig. No doubt it could be improved by a session on a RR but by how much! Once it starts to go off (between 15-20K), I will probably have a session to bring it back into line. I know the Lucas system inside out & have played with it many times in the past; goof fun if you’re inquisitive, have time to spare & like to sus things out but it’s a bit like playing Russian roulette! Quote Link to post Share on other sites
RalphC Posted March 4, 2007 Report Share Posted March 4, 2007 Mitch, I've fitted the O2 sensor so that it's permanently plumbed into the exhaust and so I'm able to look at the mixture under load conditions and at various speeds. The 'Innovate' data logging module I'm using also allows you (at extra cost) to log rpm, manifold pressure and acceleration and then download about 40minutes worth of data to a PC for analysis. I haven't got the optional extras yet and I may not need them. I've just hooked up a vacuum guage so that I can see MAP at the same time as the O2 in the car. However I must admit it would be good to be able to measure engine acceleration. I'm an engineer by trade so I'm not daunted by the task and I think I sort of understand how the MU works (famous last words). Anyway I enjoy fiddling with things like this. I'll try to work out a procedure for adjusting things in the right order. I want to sucessfully apply it myself before publishing anything. I'm sure there will be some wrinkles to work through and some compromises to be made. As far as I can see the vacuum in the manifold tells the MU how much petrol to squirt in per induction stroke. The amount of air entering the cylinder is only approximately proportional to the manifold pressure so the MU needs to match a more complex relationship between pressure and cylinder charge. So the MU has a few springs that kick in at different pressures to allow you to better match the squirt size with the engine's needs at different loads. They work via a 'datum cam' to vary fuel delivery. The adjusting screws control at what pressure the springs come in and on what part of the cam they operate. As far as I can see there is no provision to modify fuel delivery (in terms of cc per stroke) by rpm. So I guess getting it right at one rpm will mean compromise at another part of the rev range. I'm sure just diving in will result in a bit of a mess and a pit from which I may not emerge so I'll be approaching things quite methodically. Just waiting for some good weather to start road tests now. Ralph Quote Link to post Share on other sites
heliguy Posted March 4, 2007 Report Share Posted March 4, 2007 Richard, you are the first person to tell me that a MU set up on a flow bench will bolt right on to a car and give acceptable performance. This will make life easier for me! I was under the mistaken impression that this was just a starting point, and that a session on a dyno was almost mandatory, hence all my questions about adjustments and how to make them and what results you are looking for whilst on the dyno ( ok, rolling road, but dyno is easier to spell ) But having said that, I am still very interested in how you make out Ralph. I would love to run down to the garage and start fiddling with my spare MU , but instead im going to fix the brakes on my daughters "K" car. Life is just unfair sometimes......... cheers, Mitch Quote Link to post Share on other sites
Richard Crawley Posted March 4, 2007 Report Share Posted March 4, 2007 Mitch I am a little surprised by your comment & wonder just who has been advising you! With an engine in standard or recognised state of tune, a unit calibrated on a flow rig by someone who knows what they are doing will be as good as anything. Setting any car up on a dyno will always give the ultimate performance for any particular engine & they will all be different, even the condition of the engine will make a difference; but why bother haemorrhaging cash & precious time for an improvement of maybe a few % if you can bolt an acceptable unit straight on the car; these are as cheap as chips compared to the modern, electronic stuff & unless you’ve got something special or the M/U is way out, I seriously doubt if you would notice the difference on a road car; they only stay on song for between 15-20K miles before needing attention again anyway! No disrespect intended but I think you may be suffering from an infection of technicalitus. It ain’t rocket science but does need understanding & careful setting up; do you really think BL Triumph put every PI (including all the saloons!) on a dyno before driving them out of the shed! Quote Link to post Share on other sites
heliguy Posted March 5, 2007 Report Share Posted March 5, 2007 Richard, There has been so much mentioned about rolling roads throughout the archives, i just assumed that a PI car had to spend some time on the dyno to get it to perform decently. I think i will have my "good" MU looked at by Prestige, i have heard lots of good things about them, and be satisfied in the knowledge that the car will at least perform to "spec". You may have a point about the technicalitus ( my wife has another name for it ) But i like to know how things work, and how to make them work better. And yes, your right it is not rocket science, i have stripped and re-assembled a couple of these units now, and they are pretty basic compared to alot of fuel metering devices these days. Thanks for clearing up a few things in my mind for me........ cheers, Mitch Quote Link to post Share on other sites
JohnC Posted March 5, 2007 Report Share Posted March 5, 2007 Hi Ralph, I've also got an EGO sensor plumbed into the exhaust, but it's only a lowly narrow band one picked up at modest cost from a scrappie. Home made LED mixture meter and a vacuum gauge in a little pod plugged into the ashtray on top of the dash. Useful to check whether I've got the max fuel right, and to see whether idle is vaguely lean enough, but not as useful at part throttle openings as I imagine a wideband sensor is. How much did yours set you back? Cheers, John Quote Link to post Share on other sites
RalphC Posted April 10, 2007 Report Share Posted April 10, 2007 John Sorry my response is a little delayed. I've finally got my o2 'innovate' data logging system fully installed and working and have adjusted the MU. I must say I'm so pleased with the results. This is an excellent tool. I found that my 6 was running very rich at virtually all load conditions however it leaned out badly at wide open throttle and high rpm. Exactly the opposite of what you want. I could have been at risk of damaging the engine if I had taken no action. I monitor O2, rpm and manifold pressure and I now have a full map of fuelling under all load/speed conditions. It certainly allows you to understand what is going on. I'm also able to compare before and after acceleration profiles. I've managed to get air fuel ratios to sensible values (13.5 to 14.5 AFR) for cruise. It was running very rich at 10.5 so I guess I'm using 30% less fuel (still got to do a consumption check). I've also got full throttle set up better and have gained significant performance above 3500 rpm (where it leaned out previously). I've got lots of data, maps and graphs if anyone is interested. My engine is somewhat non-standard so I'm not sure how representative my experience is. With this monitoring kit it is reasonably easy to adjust the MU. Basically I just turned on the data logger and drove for 10 - 15 minutes making sure I used full rev range and a variety of crusing speeds. Then back at base the software produces maps and graphs to show you what happened. Adjust a little and repeat. I did have to make up some special tools to turn the adjuster rings on top of the MU and I had a lot of difficulty getting them to turn at all (they had been badly overtightened by someone). I'm still tweaking a little to improve things but my MU was so far out that getting it 90% set was easy. There's a screw hidden undernesth the unit that sets fuel at full throttle. Non of the other adjusters influence this. The main adjuster is the middle ring on the top of the MU which will adjust the mixture accross the whole cruise/light acceleration range. The outer adjuster will effect when the full throttle fueling kicks in however you have to consider turning this also raises the mid adjuster. The air bleed can be used to fine tune the lower rpm and light throttle fueling. The centre adjuster on top of the MU controls how lean things get on the overrun. I've still got to set this one. I'm happy to chat to anyone thinking of making adjustments. I think I have a reasonable understanding of how the metering works. What I'm not so clued up on is what air fuel ratios these engines need. I know the 'chemical' ideal is 14.7 but each engine has different requirements (presumably due to combustion chamber design, cam, exhaust etc). I'd welcome any tips from the more experienced tuners regarding this. Mixture does vary across the rpm range at full throttle so it's impossible with the PI to set ip up perfectly. Mine does run leaner at high rpm than mid range so I have to run richer than I would like at 3000rpm to get good safe power delivery at 5500. Ralph Quote Link to post Share on other sites
Andy Moltu Posted April 11, 2007 Report Share Posted April 11, 2007 Ralph has pinpointed the inherent weakness of the Lucas mechanical injection system - particularly with a tuned engine there is often (always?) a compromise between safe fueling at the very top end and running a little rich in the 3000-4000rpm range on wide throttle openings. Quote Link to post Share on other sites
tim_trinda Posted April 11, 2007 Report Share Posted April 11, 2007 I've got lots of data, maps and graphs if anyone is interested. Hi Ralph Just sent you a PM ====== Tim Quote Link to post Share on other sites
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.