DaveN Posted June 30, 2016 Report Share Posted June 30, 2016 Car starts and runs/idles fine, performs well initially, but if I switch off for 10 minutes or so when restarted it seems to run on five. It will seem to clear if I thrash it but then plays up at low RPM. So back home a very weak pulse from certainly one of the injectors, however they are all new, so with the engine running I disconnect the number 1 hose from the MU result... practically nothing coming out of the adaptor! I would have thought that it would be a big healthy spurt with each revolution? Thoughts gents Dave Quote Link to post Share on other sites
Nigel Triumph Posted June 30, 2016 Report Share Posted June 30, 2016 The problem may be nothing worse than a blocked or faulty non-return valve on the MU outlet to the affected injector line. Have you looked at cleaning or replacing the NR valve? Nigel Quote Link to post Share on other sites
DaveN Posted June 30, 2016 Author Report Share Posted June 30, 2016 Hi Nigel. Yes I pulled the NRV and checked it by poking a small dowl up it against the spring. Still the same just a small 'splash' with the engine running. I may just pop down to Moss and get a new set any way. Quote Link to post Share on other sites
Peter Cobbold Posted June 30, 2016 Report Share Posted June 30, 2016 (edited) Dave, The volume of fuel delivered at tickover is tiny, just enough to make a few horsepower, maybe 2 to 3. You'd get more fuel per squirt by opening the manifold-MU hose to atmosphere. That would give fuel as if the engine were at 800rpm full throttle, guessing 20hp. Fuel flow for engine making 20hp is around 1.9 ml per sec So for one injector you'd expect 0.3ml per sec. With your test, with the MU connected to the manifold at tickover, for 3 hp, the fuel flow per injector will be 0.04ml per sec. That's best visualised as a cube of side ca 3.5mm. So 'practically nothing' is quite likely shows the MU is working correctly. A big healthy spurt would be wrong. Peter Edited June 30, 2016 by Peter Cobbold Quote Link to post Share on other sites
DaveN Posted June 30, 2016 Author Report Share Posted June 30, 2016 Thanks Peter Ah of course that would make sense. I'll give it ago with the hose disconnected.... And I'll try the injector. I had discounted that as it is a new unit. Will report back later. Dave Quote Link to post Share on other sites
Andy Moltu Posted June 30, 2016 Report Share Posted June 30, 2016 Odds on it is the injector. Take it off, blow it out with an airline then put it back and give it chance to bleed. Quote Link to post Share on other sites
DaveN Posted June 30, 2016 Author Report Share Posted June 30, 2016 Right, the plot thickens! Changed the injector twice, nothing out of the injector at all, so as Peter quite rightly pointed out I disconnected the vac line to the MU. After 30 seconds or so the injector starts to dribble then slowly the spray emerges. Connecting up the vac line and plugging the injector back in and.... Back to 5 pots. Pull the injector and....nothing! Baffled of Langley! Btw they ware all recon injectors. Dave Quote Link to post Share on other sites
DaveN Posted July 1, 2016 Author Report Share Posted July 1, 2016 Update: Tried again this morning with a cold engine. Full choke car started straight away, BUT clearly running on 5 pots pulled no.1 injector ...... No flow at all. Disconnected the M U vac. line and within seconds a good cone spray and car running on all cylinders. Reconnect vac line and flow from the injector stops! Even more baffled now. BTW just to add Bosch pump and filter assy. PRV is a prestige type. Dave Quote Link to post Share on other sites
stuart Posted July 1, 2016 Report Share Posted July 1, 2016 Talk to Neil Ferguson 07977001571 Stuart. Quote Link to post Share on other sites
DaveN Posted July 1, 2016 Author Report Share Posted July 1, 2016 Hi Stuart Yes thanks, Neil was going to be my next port of call. I have dealt with him before and found him extremely helpful. Dave Quote Link to post Share on other sites
Steves_TR6 Posted July 1, 2016 Report Share Posted July 1, 2016 Neil will sort you out. The rest of us are baffled by the Lucas pi system, well I am ! Steve Quote Link to post Share on other sites
DaveN Posted July 1, 2016 Author Report Share Posted July 1, 2016 Well, spoke to Neil ....what a gentleman time to speak nothing too much trouble! He had seen the thread on here and was probably expecting the call! Anyway the MU is winging its way to Stafford as I type! :-) 20 mins to remove......an hour to find a box! Dave Quote Link to post Share on other sites
Clarkey Posted July 3, 2016 Report Share Posted July 3, 2016 (edited) Dave Neil as the rest have said will sort it for you. Takes a little longer to fit p.s a Ratchet spanner helps. Edited July 3, 2016 by Clarkey Quote Link to post Share on other sites
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