GP2.5 Posted March 22, 2015 Share Posted March 22, 2015 Hello Josh, Flow will drop off a lot when you run a pump at a higher pressure than it was designed for, So what is the number of the pump you are using? Most pumps are designed for 3-4 bars I run a - quiet -Pierburg E3T pump on My PI . That Pump is designed for a 6.5 bar pressure , the flow is 110 liters at that pressure. So regulating it upp slightly to PI pressiures will still give a graet flow Almost all Bosch pumps that I know off are running on the edge at Lucas PI pressures GP Link to comment Share on other sites More sharing options...
spitfire6 Posted March 22, 2015 Share Posted March 22, 2015 Not sure if you can increase the flow rate of a pump at rated pressure by restricting is outlet. A replacement pump needs to have at least its outlet pressure greater than the PVR? Cheers, Iain. Link to comment Share on other sites More sharing options...
josh18 Posted March 23, 2015 Author Share Posted March 23, 2015 Hi GP, thanks for that. I can't remember the number of my pump but it's rated to about 400hp on a conventional efi engine. The ones I have been recommended is the Bosch b26 205 413, which flows 200l/h at 116 psi. The kicker is they cost at least $700! The bosch 044 is the next best and flows the same but at about 70 psi. These are much more reasonable at about $150. Just for reference the 044 is rated at about 600hp, so much more flow than mine. So on the list is one of these pumps, and quite a few mods to the fuel delivery, particularly before the pump inlet to increase flow and eliminate cavitation, which the pumps are prone to. cheers Link to comment Share on other sites More sharing options...
pomwah Posted March 23, 2015 Share Posted March 23, 2015 Josh, I've got a used fuel pump spare, I was bidding on three pumps on eBay and, I still don't know how it happened, won all three. If you want to try one out shoot me a PM. Link to comment Share on other sites More sharing options...
Nick Jones Posted March 23, 2015 Share Posted March 23, 2015 The Pierburg ET3 looks like a very decent pump. Its a gear pump (like the original PI pump) rather than roller cell like the Bosch ones. Probably not cheap...... can't find a price anywhere. If sticking with a Bosch one, you need to choose one that comes from a large engined K-jetronic equipped car (Big Merc, Audi or similar) as those systems run about 80 psi and going up another 25 psi doesn't knock the flow down that much. None of the "ordinary" EFI pumps will be much good as they are designed for around 45psi so if you make them push against 100psi the flow will drop right off and they'll die young too. Suction conditions are important on any PD pump but especially these roller cell pumps and especially in warmer climes. Nice big line from tank to pump (including tank outlet) and a big strainer rather than a true filter will work wonders. Put an HP filter on the outlet side. Nick Link to comment Share on other sites More sharing options...
spitfire6 Posted March 23, 2015 Share Posted March 23, 2015 Hi EFI HP to Pump rating is meaningless when you are tiring to compare it to a PI system. Most EFI systems run about 50 PSI. PI runs at about twice that. You need a pump that flows more than you need and at a higher pressure than you need. What voltage do you have at the pump while the engine is running? It does make a very big difference. Especially with PD types. IF the volts are below 13 volt a cheap <10GBP voltage booster can be used to bring it up to over 13V and up to 14.7V, that will make a big difference to flow rate and pressure. Cheers, Iain. Link to comment Share on other sites More sharing options...
Triumph-V8 Posted March 24, 2015 Share Posted March 24, 2015 I used an additional wire 2,5qmm from battery direct to pump that is engaged by a relais close to the pump what is driven by the older, original wire. There are two advantages: There is best voltage and the ignition switch gets less load. If the "normal" BOSCH pump does 50 psi why not add another pump in serial connection? So each of them does an increase of 50+ psi what can do happily..... On low load the PI runs properly with less pressure so be sure that missing pressure is really the reason for the problems.... Link to comment Share on other sites More sharing options...
josh18 Posted March 24, 2015 Author Share Posted March 24, 2015 Thanks guys. Nick, the 044 is the second best pump that Bosch make. It is a motorsport spec, does about 70psi @ 200 litres per hour. What you said about good flow to the pump is pretty much what I plan to do, including getting the tank outlet oversized. One other possibility I haven't mentioned is the boost pump I run could be not enough flow for the system and holding up the pump at high demand. I need it now as I run a surge tank, but with the tank mods I can delete it from the system. Spit six, I know efi and lucas don't compare, but the main difference between my pump and the 044 is the flow- 150 vs 200 L/h, both at around 70 psi. As far as I see it in the Lucas set up, if flow is inadequate to fuel demand at high end then pressure will drop, possibly causing the injectors not to fire. If I can increase the flow at the same pressure then I should not have that problem. TV8, cheers for that. I have pretty much the same setup as you mentioned for wiring but need to look it over and make sure all is well. Some bigger wire and bigger relay might be in order, as well as proper soldered connections. First things first though, I have got my fuel pressure gauge mounted, just need to get some fittings to plumb in the sender. Watching what the fuel pressure does throughout the rev range will give me an idea if I am on the right track, but until then its just theories. Cheers for the help guys Josh Heres a pic of the gauge install. The black gauge is to be the fuel pressure and the one to the left is AFR, when I get that wired up. Less important stuff I have moved down near the stick, with space for one more. Link to comment Share on other sites More sharing options...
GP2.5 Posted March 24, 2015 Share Posted March 24, 2015 Hello all, As Nick say it,s a gear pump, and it is quiet. It has a huge 16 mm inlet so a step-up adeptor is needed on the intake side, guess that the pre-pump 16 mm fuel hose reduces cavity. Still a larger outlet from the tank would be the best. To my best knowledge the Pierburg was used on Ferrari 400i with K- jetronic, at the time mine was cheaper than a Bosch 044. You will find it at YOUREX a very well supplied swedish supplier of all sorts of fuel pumps,fans, generators starters etc. Before the Pierburg I was running a Lucas pump with a Facet pre pump, that worked just perfect untill the Lucas pump started to fail. I love the Lucas PI, I would never change to ECU injection Gunner Link to comment Share on other sites More sharing options...
josh18 Posted March 25, 2015 Author Share Posted March 25, 2015 Thanks guys i will look into the peirburg,it sounds reallh good! i had a breakthrough tonight im very happy to say, telling me im heading in the right direction. i plumbed up my PRV return into the top of my surge tank as i originally had it. Its very similar to how early tr6s were done I am told. I did this because i think the boost pump couldn't fill the pot quick enough for the HP pump, and especially under braking fuel was sloshing forward and the pump would suck air in. Now I have the boost and the prv return filling the pot, with return to tank from there. So, now i have no air sucking under braking but also much cleaner running up high! This tells me the boost pump is a major hold up in the system. the reason i went away from this in the first place is that the pump was making strange noises at low revs, when most of the flow was going back to tank, lifting a head of fuel from the pot to the tank. I thought i had stuffed the pump. After further reading i found that it could be the return line resonating, which made sense as it sounds like worn pipes in a house. Now my setup is slightly different, where less fuel has to be lifted to return to tank. I have also added a filter to the return line which i have been told helps any air in the line go back into solution- it is clear and you can see it working. anyway this is much btter than before, and if the pump does wear out because of it, which i dont think it will, i have a spare on board. I'll keep you guys posted. cheers Link to comment Share on other sites More sharing options...
Mike.Luis Posted March 25, 2015 Share Posted March 25, 2015 Hi Josh, will be interesting to see what the pressure gauge is showing at high revs. I just finished the plumping of my Bosch pump arrangement and am also using a tubular manifold similar to yours. As far as I know, the pump is coming from an Audi 2.3L Turbo from the 90th, which probably is not up to the job for a Lucas metering. I aslo don't know the part no. of this pump. Anyway, we will see in the next few weeks hopefully. The pump has a large inlet side of 16mm and I connected everything from tank to pump with a dash 10 hose (ID 14,7 mm). The tank is stainless steel with integrated swirl pot and the tank outlet is 12 mm ID, which is at the moment the bottleneck. The outlet ID can be increased to approx. 14 mm if needed. I use a 4 mm/2 wire and relay for the pump. Attached are some pics of the installation. Cheers, Mike Link to comment Share on other sites More sharing options...
josh18 Posted March 26, 2015 Author Share Posted March 26, 2015 Hi Mike, I was just looking at you photos- that manifold looks great! Did you make it yourself? Your tank plumbing looks very similar to what I plan to do with mine. Im keen to see how it goes too! Link to comment Share on other sites More sharing options...
toofast2race Posted March 28, 2015 Share Posted March 28, 2015 Hello Josh, Flow will drop off a lot when you run a pump at a higher pressure than it was designed for, So what is the number of the pump you are using? Most pumps are designed for 3-4 bars I run a - quiet -Pierburg E3T pump on My PI . That Pump is designed for a 6.5 bar pressure , the flow is 110 liters at that pressure. So regulating it upp slightly to PI pressiures will still give a graet flow Almost all Bosch pumps that I know off are running on the edge at Lucas PI pressures GP Found this on Pierburg pumps - certainly very informative with pump curves http://download.ms-motor-service.com/ximages/pg_pi_0034_en_web.pdf Link to comment Share on other sites More sharing options...
GP2.5 Posted March 28, 2015 Share Posted March 28, 2015 Hello Hot Shoe! Yes very informative indeed, I made my "pick" from that info. You have the skills! Should I fit a TR5 exhaust manifold with a very decent downpipe to my PI My69 or should I go for the 6-3-1 from Mr Witor? Are we talking about more or less than 5 Hp improvement. Love to listen to your white PI on the rollers, Best Regards Gunner Link to comment Share on other sites More sharing options...
toofast2race Posted March 29, 2015 Share Posted March 29, 2015 TR5 twin downpipe is a lot cheaper if you have one - They seem to give great torque with no real downside - I would try it before spending the 450 quid if you have one handy as the current Witor 6-3-1 is a compromise and needs modification even as it is sold - ie a bigger out let to the collector Link to comment Share on other sites More sharing options...
GP2.5 Posted March 29, 2015 Share Posted March 29, 2015 Thanks, - I know that I am off topic - My downpipe is 2X40 mm ID, Y-pipe outlet is 21/8 OD - ie a true 2" inch pipe. I "guess" that it should be at least 21/4" But still this is what I got. Cheers Gunner Link to comment Share on other sites More sharing options...
josh18 Posted April 16, 2015 Author Share Posted April 16, 2015 Hey guys. I think I am much closer to solving my issues, by taking my fuel pump plumbing setup back to square one and doing it like it should have been done. I had the pipes from the tank to the bosch pump upsized to 1/2" ID and have now omitted the boost pump and surge tank completely. I had thought this might be a compromise and I would get surging round corners, but upon taking out the fuel float to have a look inside the tank, realize that my tank has baffles or an internal surge sank of some sort so an external one isn't needed. The hardest and scariest part of the mod was that I had to drill out the boss on the outlet of the tank and tap it out to 3/8" BSPT. I did it in situ, and just took it very slowly with the drill, and tapped it out very carefully. I was worried about the taper tap splitting the boss open, but thankfully it went really well. I got it running tonight and it runs at least as well as before with only a gravity feed to the main pump, which it has never done before. There is still a slight misfire at high revs but not like before. I still need to get a better HP pump I think, though I am yet to plumb up my fuel pressure gauge so its still just a theory. Im very happy to have the "distillery" out of my boot, and also be rid of the noisy boost pump, and I also feel a lot safer without all the fuel components I had in there. Also, I drove it for the first time with out the rear section of the exhaust, and it sounded and went much better-I think I gonna have to weld up a new section with no muffler in to for the back. Link to comment Share on other sites More sharing options...
josh18 Posted May 2, 2015 Author Share Posted May 2, 2015 Hey guys. To add to the last post, here is a pic of my current pump setup. It is much better and much simpler. I was thinking of putting a filter before the pump as I have been told that pump fuel is dirty enough to wreck these pumps quickly. Will this affect my hard won fuel flow though? Link to comment Share on other sites More sharing options...
pomwah Posted May 2, 2015 Share Posted May 2, 2015 I don't think a pre-pump filter will reduce the flow that much. I have been labouring under the assumption that the function of a swirl pot, put me right if I'm wrong here, that you call a surge tank, is to stop aerated fuel, returned to the tank from the PI fuel rail/system, being directly fed back to the engine. Link to comment Share on other sites More sharing options...
Nick Jones Posted May 2, 2015 Share Posted May 2, 2015 I would be wary of putting a true filter before a Bosch style pump - they really don't like suction restrictions. It is true about them being fairly dirt intolerant though. All the genuine Bosch pumps I've seen have a built-in inlet-side strainer (visible through the inlet port) and most OE fitments seem to rely on this, sometimes with an additional in-tank pick-up strainer. The non-genuine pumps don't all have these strainers (the one I got from Sytech doesn't) so I've started using inline strainers like this http://ricoeurope.com/metal/bf1173.html?gclid=CL3T1uf4osUCFfQZtAodMkAAYg (which reminds me, my pump has started making sad noises at just under 1/2 so I need to investigate the strainer and backflush.......) Nick Link to comment Share on other sites More sharing options...
JohnD Posted May 2, 2015 Share Posted May 2, 2015 (edited) I don't think a pre-pump filter will reduce the flow that much. I have been labouring under the assumption that the function of a swirl pot, put me right if I'm wrong here, that you call a surge tank, is to stop aerated fuel, returned to the tank from the PI fuel rail/system, being directly fed back to the engine. It's called a 'surge tank' because it's function is 'anti-surge'! A main tank, much less than half full, can expose the end of the intake pipe inside the tank, so that the pump draws in air. There being no way of trapping that air after the pump, it gets injected into the engine which goes very lean, can cut out. It is a 'swirl' pot, because it is circular in plan. A 'lifter' pump takes fuel from the main tank, and inserts it into the swirl pot, tangentially, along the side of the 'pot', at the top, so that the fuel swirls around inside it. This puts the heavier fuel on the outside and the air in the middle, where a convenient drain port allows it to escape back to the main tank. The lifter runs continually, circulating and swirling the fuel, while the take off to the main pump is low down, so even if the tank does surge, and the lifter draws air, the air never gets to the main pump. Other anti-surge tank ideas are used, principally a small tank inside the main, that traps fuel inside and has sufficient volume to supply the main pump through the longest corners. You may have seen/heard this referred to in F1 towards the end of a race. A driver running very short will weave his car, sloshing the remaining fuel about in the tank so that the anti-surge tank can trap it. Triumph fitted early Lucas Pi cars with a "swirl chamber" fed by gravity and the MU's return. Later, they fitted a simple cup in the main tank, that fuel sloshed into, as above. Strange, as the Fuel filter housing has a port on top that would make it function as a swirl pot. And Herald Estates had a small collecting cup under the very wide and surge prone main tank. John Edited May 2, 2015 by JohnD Link to comment Share on other sites More sharing options...
pomwah Posted May 4, 2015 Share Posted May 4, 2015 Thanks for clearing that up John. Link to comment Share on other sites More sharing options...
josh18 Posted December 29, 2015 Author Share Posted December 29, 2015 hey all. I am still having the same issue I have always had since I fitted the header- misfiring above about 5500rpm. As I have said in previous posts the fuel delivery side is much improved- half inch line from tank outlet to pump mouth, a` Link to comment Share on other sites More sharing options...
josh18 Posted December 29, 2015 Author Share Posted December 29, 2015 Sorry, stuffed that last post. I am still having the same issue I have always had since I fitted the header- misfiring above about 5500rpm. As I have said in previous posts the fuel delivery side is much improved- half inch line from tank outlet to pump mouth, motor sport pump equivilent to a bosch 044, an electric sender analogue fuel pressure gauge reading up to 120psi and an AFR gauge. So basically, my fuel pressure is sitting at about 105psi and not decreasing, (havent tried increasing this yet) right up to the mis-fire point. My AFR is reading about 12:1 when the car is running best throughout the rest of the rev range and does lean out to around 13 as the revs climb but I dont think this seems too bad. If I wind the full load screw in more to try and richen up the top end it is way too rich in the mid range to the point of fouling, but the misfire up top still remains, even though it is well rich. A couple of things I have noticed- I took it for a short run the other day and accidentally left the choke half on. This was bad and duly fouled up the plugs before I realised. What was unexpected was that plugs one and three when removed were completely clean and white, while the rest were black as char. lines one and three happen to be two of the three furthest away from the fuel supply on the MU, which I think may be backed up by how much fuel is leaking past the case drain in the MU. Ive heard it's only supposed to be a trickle- mine is a fair bit more. I guess if there is too much leakage there the lines furthest from the supply could be starved at high demand, but be ok for normal running (they have a fine spray pattern when cranked over). Also I can imagine that the overall AFR may not change too much if a couple of injectors were under performing as the sensor is in the collector of the header. In any case it's doing my head in! Away from fuelling, I have tried a simon BBC electronic distributor, and now pertronix electronic ignition on a 25d distributor, new leads not long ago, new plugs, cap and rotor button. I have also tried it grossly advanced and retarded with no change. I have tried larger and smaller plug gaps and also cooler plugs to no avail. Is there something on the ignition side I could be overlooking? Im still really thinking fuel, especially considering this issue began instantly when I fitted the new header, which by the feel of it is a hell of a lot freer up top. With the old cast manifold it would rev to 6000 with no mis-fire no worries. There was just no point though because it was so restricted, but proves I think the ignition was up to the task. The MU is supposed to be set up for my tr5 cam, but I have't played too much with the adjusters on top, just the full load setting. As far as I can see from reading, tuning the top end should be the easy part and the mid range is the hard part. A few things I have been thinking of trying are along the lines of increasing the pressure at the PRV ( I remember GT I think saying you need more like 120 psi for high performance) or even putting some sort of restriction in the case drain line to see if anything changes, I worry that increasing the prv pressure will just increase case drain losses though. Other than that Im pretty stumped. Also, my whole MU/ injectors were reconditioned not that many km ago, and otherwise seems to be in good condition. In any case, any help would be really appreciated, even if it is to tell me my MU is stuffed. If so I'm not going to have it re-co'd again, I'll be going EFI! Cheers Josh Link to comment Share on other sites More sharing options...
Nick Jones Posted December 29, 2015 Share Posted December 29, 2015 You've been through pretty much everything I would have suggested. Seems to be confirmed that the basics are in place. One point to keep in mind is the AFR meter (wideband presumably?) is actually an O2 sensor, so gross miss-fires show up as lean (or a leaning effect) due to the excess oxygen from the unburned charge, even if the miss-fire was cause by being too rich. Interesting about cylinders 1 & 3. Don't know enough about how the MU works to fully dissect that. Do you also get a differential colour if the choke is not out? Calling Andy T.......... Cheers Nick Link to comment Share on other sites More sharing options...
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