iani Posted March 10, 2020 Report Share Posted March 10, 2020 17 hours ago, john.r.davies said: Thnak you, Spit2.5! Most informative! But that information says that the max pressure on an E3T, or any of these, is 94psi. When the specified pressure for Lucas Pi is 100psi, is that sufficient? JOhn Gary Bates (TRGB) had me set my Bosch style pump to 95psi when I was running the Lucas injection and it worked just fine. Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 10, 2020 Report Share Posted March 10, 2020 (edited) 2 hours ago, john.r.davies said: Thank you, Peter! However, that page doesn't include a non-Lucas fuel pump. I previously asked KMI is they could replace the one I have, and they cannot, which made me more cautious about the Pierburg. That you at C&B had to go to such trouble to make them fittable increases my caution, and I'm going to try again tio get this one working. And I note Richard's point about "up to 150psi" whihc appears in the spec, without explanation. John Hi John, I am now tripping down memory lane.....All these ideas we mulled over or tried 40 years ago. I recall the main complaint about the Lucas pump assembly being the motor not the pump part. So can you get a suitable power brushless DC motor and attach it to a Lucas geared pump? The other issue with the Lucas pump installation in aTR was the vertical orientation fitment in a confined airless space. The motor armature thrust being taken by the pump gears is a rubbish design. Cool the motor, lay it down, beef it up and you could be on to a winner. There was a car with twin Lucas pumps to try to reduce the load on the motors. The outlet size to the pumps was important or they just screamed. The Bosch pumps required a large fuel flow at the inlet, greater than the standard Lucas which is addressed by additional or larger tank outlets. The Facet priming pump was a good option, which you have adopted. A reservation was main pump demand exceeding Facet supply but you have addressed that too. Pierburg pumps were tried but I do not recall them surpassing the Bosch units. The idea that Bosch was the magic bullet was misplaced as the Bosch system is said to be hyper sensitive to any water ingress in the fuel causing corrosion to any component. Cheers Peter W Edited March 10, 2020 by BlueTR3A-5EKT Quote Link to post Share on other sites
Waldi Posted March 10, 2020 Report Share Posted March 10, 2020 Hi John, the Bosch pump I installed (after my old Bosch xx 996 started leaking from the rubber wire conduit) is 0580.464.126. I selected this on its pump curve and current draw which looks like best suitable from the current range of pumps (but far from ideal, as we all know) . It was also recommended by Ben, who is accasionally on this forum too. Pierburg: there are several Pierburg E3T pumps, the correct most suitable one I think would be 7.21659.70.0 Here is a link (copy past in your browser please if not working I cannot copy a working link: Maybe there is an english version available too? http://www.wilmink.nl/pierburg/Pierburg_brandstofpompen.pdf Regards, Waldi Quote Link to post Share on other sites
roy53 Posted March 10, 2020 Report Share Posted March 10, 2020 Hi John looking at your setup your boot now looks very cluttered . I think 4 filters before the pump is restricting the flow and not helping. [ Plus 1 in the prv ] if it holds the pressure before starting then drops when on demand i think would indicate a restriction on incoming fuel to the pump. Your swirl pot will also be restricted if it is not getting the required supply and its outlet size to small. As you have so much space you could fit a lucas pump lying flat as in PI saloons . Not ment as criticisms just trying to help. ROY Quote Link to post Share on other sites
Waldi Posted March 10, 2020 Report Share Posted March 10, 2020 I prefer to keep things simple (also no offence intended) I have considered the 2nd pump boosting inlet pressure of the Bosch pump too, it will certainly reduce risk of cavitation and I also considered a pre-filter AND post filter. I ended up with just the Bosch pump and a very large but fine suction-side filter. The risk of wear particles from the pump damaging the MU is still there, but my theory is the MU and the injectors all have their own inlet filters selected by the Triumph/Lucas engineers. I think the PRV is less sensitive; time will tell. Again a classic case of each following own ideas. Waldi Quote Link to post Share on other sites
john.r.davies Posted March 10, 2020 Author Report Share Posted March 10, 2020 Again, thanks to all! Roy, that is an old pic, and the filter before the Facet has gone. It WAS a restriction, as despite being about half thr szie of a beer can, the actual filter inside was only as big as my little finger! So there are two filters before the main pump, one in the Facet, fairly coarse, and the blue-red one, recommended by my original supplier, who also supplied the post-pump, very fine filter. But a filter in the PRV?? I think not. And I mounted it all on the cross tunnel, so that I could fit a false floor to the boot for touring. The floor sits on those raised posts that double as tank fasteners (there are four in total) an has a rear lip so that luggage rest on neither the tank, it's hoses or the equipment. Another addition is a 'cigar-lighter' socket, so that I can slide a laptop under the floor and charge it as I go! Waldi, I don't consider that the Facet "boosts" inlet pressure to the Bosch. It's a lifter pump to keep the swirl pot full, in the face of cornering surge in the tank. As the pot is higher on the bulk head than the pump, it does provide a small hydostatic pressure to the input. But my thinking on this fault has changed. The initial adequate pressure, followed by a rapid fall, now to zero (!) implies that it is the PRV that is at fault, and that the bypass is sticking open under pressure, so that ALL the output from the pump is directed back into the tank. Further investigation has found a copious flow that way, but if the main hose is disconnected from the M/u, that flow is similarly copious. The present PRV is a Malpassi unit, and dismantling it found a floppy looking diaphragm, so I've ordered a replacement. Let you know progress. John Quote Link to post Share on other sites
Waldi Posted March 10, 2020 Report Share Posted March 10, 2020 Aha John, that could well be it. Was the diaphragm attacked by the fuel (ethanol) or “floppy” because of another issue? Waldi Quote Link to post Share on other sites
john.r.davies Posted March 10, 2020 Author Report Share Posted March 10, 2020 No idea, Waldi! It wasn't even very floppy - I don;t knowe what ot should look like! The replacement will be here in a couple of days; I'll know then. I suppose that the diaphragm design of the Malpassi is a disadvantage in this alcohol fuel age. The OE spring loaded design would not suffer from ethanol degradation. John Quote Link to post Share on other sites
Waldi Posted March 10, 2020 Report Share Posted March 10, 2020 You could ask confirmation. I would be surprised if it was not John. Waldi Quote Link to post Share on other sites
Mike C Posted March 10, 2020 Report Share Posted March 10, 2020 On 3/10/2020 at 4:08 AM, john.r.davies said: Thnak you, Spit2.5! Most informative! But that information says that the max pressure on an E3T, or any of these, is 94psi. When the specified pressure for Lucas Pi is 100psi, is that sufficient? JOhn If you can get a Viton diaphragm. I installed a nitrile diaphragm from one of the major suppliers in the MU and stale modern mix 98 octane fuel destroyed it within hours. Same rapid fall off in performance as you experienced. My PRV is the old OE brass style and I'm happy with it. And I've found since Stabil solves the stale fuel problem- but I would never use anything other than Viton for the PI elastomers. Quote Link to post Share on other sites
john.r.davies Posted March 12, 2020 Author Report Share Posted March 12, 2020 New diaphragm arrived. Here's the disassembled valve: Left to right: Valve body, valve diaphragms - below, centre OE part, above TWO alternatives! - spacer, bottom collet, spring, top collet, valve cover, with gasket (new gasket above) Here's a close-up of the OE diaphragm, and the new ones. You can see what I meant about 'floppy', especially in comparison. The OE D'gm has three layers of rubber, while the two replacements have two layers. And they have different central fixtures, that engage with the spring and hold the valve itself that returns fuel to the tank. In the pic, you can see that the two new ones have a top (left, to spring collet) and bottom (right, to valve face) fixtures that match the original. But their other sides are each different, in particular the bottom valve on the left d'gm was significantly narrower. I therefore used the new diaphragm on the right, although the backing washer behind the valve was much narrower. Result? F-all. Still get a brief rise to 100psi+, rapidly sinking to zero. Back to the Fuel pump? John Quote Link to post Share on other sites
ntc Posted March 12, 2020 Report Share Posted March 12, 2020 Yep And I did see your swirl pot you have a short memory John , remember me helping you with your tank venting a long time ago ? Quote Link to post Share on other sites
Waldi Posted March 12, 2020 Report Share Posted March 12, 2020 John, regardless of the pump issue that may still have, that membrane is attacked by the fuel. Put some fuel on NBR and you will see the same. It swallows and get’s softer. Wat is the new material made off? Be carefull, it could have different layers, like one Viton and the other nbr. Waldi Quote Link to post Share on other sites
john.r.davies Posted March 12, 2020 Author Report Share Posted March 12, 2020 On memory, I plead age! I think I may go back to the OE PRV! John Quote Link to post Share on other sites
john.r.davies Posted March 13, 2020 Author Report Share Posted March 13, 2020 Further investigations. Clamp the PRV return - no effect. Strip the pre-main pump lines - all clear, no obstruction, pre-pump filter clean. Lifter pump delivers a good flow to the Swirl pot, judged by the return flow from that. Tried to re-circulate a fuel jug full of fuel, with added injector cleaner. Flow from main pump very poor, and I notice that the pump is now "groaning". Odd, nasty noise. I think it has to be the main pump! Quote Link to post Share on other sites
Mike C Posted March 13, 2020 Report Share Posted March 13, 2020 What pressure are you getting with the PRV return clamped and the engine not running- should be close to the shut off head specified by Bosch for your pump. Quote Link to post Share on other sites
Waldi Posted March 13, 2020 Report Share Posted March 13, 2020 42 minutes ago, Mike C said: What pressure are you getting with the PRV return clamped and the engine not running- should be close to the shut off head specified by Bosch for your pump. Good idea, as long as the prv allows some fuel to pass. To measure real shut-off head better to measure directly at pump discharge. This then rules out any prv influence and would be a strong indicator for pump condition. Current draw is another simple thing to measure, see if it matches the curve at zero flow (which is shut at off head). Run John, run! Waldi Quote Link to post Share on other sites
john.r.davies Posted March 14, 2020 Author Report Share Posted March 14, 2020 Bypass clamped or not, zero pressure. Quote Link to post Share on other sites
Waldi Posted March 14, 2020 Report Share Posted March 14, 2020 That’s not good. Have you checked that you have 12 V at the +ve and 0 V at the -ve connection on the pump while running? If that’s ok too, time to remove the pump. Last thing could be air on suction side. You don’t need much to completely loose performance. Think af a submerged pond pump that’s just started, it first needs to purge out the “mist” the rotor makes from air/water. A bench test can rule that out. Waldi Quote Link to post Share on other sites
BlueTR3A-5EKT Posted March 14, 2020 Report Share Posted March 14, 2020 On 3/12/2020 at 2:19 PM, john.r.davies said: New diaphragm arrived. Here's the disassembled valve: Left to right: Valve body, valve diaphragms - below, centre OE part, above TWO alternatives! - spacer, bottom collet, spring, top collet, valve cover, with gasket (new gasket above) Here's a close-up of the OE diaphragm, and the new ones. You can see what I meant about 'floppy', especially in comparison. The OE D'gm has three layers of rubber, while the two replacements have two layers. And they have different central fixtures, that engage with the spring and hold the valve itself that returns fuel to the tank. In the pic, you can see that the two new ones have a top (left, to spring collet) and bottom (right, to valve face) fixtures that match the original. But their other sides are each different, in particular the bottom valve on the left d'gm was significantly narrower. I therefore used the new diaphragm on the right, although the backing washer behind the valve was much narrower. Result? F-all. Still get a brief rise to 100psi+, rapidly sinking to zero. Back to the Fuel pump? John Coo that lower diaphragm rubber looks just like the one I recently removed as 'suspect not working' from my mechanical TR3 fuel pump. Cheers Peter W Quote Link to post Share on other sites
Mike C Posted March 14, 2020 Report Share Posted March 14, 2020 4 hours ago, john.r.davies said: Bypass clamped or not, zero pressure. If the Bosch pump is getting fuel from the Facet pump /swirl tank and still not generating any head then it looks like it's time to replace the Bosch - but you need to find out what caused the failure to prevent it happening again. Quote Link to post Share on other sites
john.r.davies Posted March 14, 2020 Author Report Share Posted March 14, 2020 That is my greatest concern, MIke C! This happened once before, after a winter lay-over, but this time I put fuel stabiliser in, circulated the fuel and then drained the tank in Autumn. Pumps shouldn't be consumeable items! John Quote Link to post Share on other sites
JohnC Posted March 15, 2020 Report Share Posted March 15, 2020 Hi John, That initial high pressure, followed by a big fall, does suggest to me an inlet problem. If it's not too much of a pain, why not try taking a (new) hose direct from the fuel tank outlet to the pump? That would tell you if there's any blockage you need to look for in the stuff you've by-passed. I once found a tiny piece of plastic bag blocking the pump inlet filter that way. I know you're an old hand at this, but sometimes the obvious...isn't. JC Quote Link to post Share on other sites
roy53 Posted March 16, 2020 Report Share Posted March 16, 2020 Another vote for the inlet being the issue then John . Could be caused by the tank venting . I would do as above but take of the filler cap in case of vacuum or rig up a supply direct to the pump from say a funnel. If that dosen't work then it's the pump or power to it. ROY Quote Link to post Share on other sites
astontr6 Posted March 16, 2020 Report Share Posted March 16, 2020 On 3/10/2020 at 7:04 PM, Waldi said: Aha John, that could well be it. Was the diaphragm attacked by the fuel (ethanol) or “floppy” because of another issue? Waldi Hi All! That diaphragm shows a classic case of blistering which is caused by a reaction with petrol, but it may not have been caused by the ethanol content. When people specify Viton it must be the type B and not the A type which does not withstand any type of petrol as there are plenty of other nasties in petrol to attack Viton. I have used the original Lucas type for 47 years without any trouble! Bruce. Quote Link to post Share on other sites
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