RobinTR6 Posted April 23, 2015 Author Report Share Posted April 23, 2015 (edited) Its a trick of the light and angle, all hoses are without kinks or very tight bends. Just checked tank outlet, petrol flows freely from tank without hose to filter and with hose to filter. Removed the hose tap (just in case) and replaced with 5/16 petrol hose......still the same , ie cant get above about 95PSI.Still like a dog past 3k revs Cav filter from well known supplier and it does have 2 inlets and 2 outlets, Ive just used a pair from one side (cant see what it should be an issue, ther are marked with arrows one pointing in other points out). Run out of ideas............. Edited April 23, 2015 by RobinTR6 Quote Link to post Share on other sites
TR NIALL Posted April 23, 2015 Report Share Posted April 23, 2015 Try bypassing the Filter and Pipe the Fuel direct to the Pump,it's a matter of going through everything Step by Step. Quote Link to post Share on other sites
RobinTR6 Posted April 23, 2015 Author Report Share Posted April 23, 2015 Ill need to think about how to do that as the inlet to the filter is 5/16 from the tank but the outlet is bigger braided hose with a swaged bsp size nut to match the other end at the pump. Ill order another filter , albeit that the one in there is new. Its in my picture on earlier post. Quote Link to post Share on other sites
Guest ntc Posted April 23, 2015 Report Share Posted April 23, 2015 You have checked that the tank is venting as it should? Quote Link to post Share on other sites
RobinTR6 Posted April 23, 2015 Author Report Share Posted April 23, 2015 Neil, yep....theres a pipe in top of tank which has a hose connected that runs to the chassis thru boot. Its clear and if I blow down it the air come rushing back out one ive stopped blowing. Quote Link to post Share on other sites
TR NIALL Posted April 23, 2015 Report Share Posted April 23, 2015 Disconnect at the feed to the Metering Unit and with Ignition On Measure the flow coming from Pump,again have a few Buckets at the ready and someone to disconnect Power. Quote Link to post Share on other sites
astontr6 Posted April 23, 2015 Report Share Posted April 23, 2015 Robin, Have you disconnected the fuel line from the filter at the in put side of the pump to check the gravity flow rate of 1 litre per minute + into a container? If so what was the result? Bruce Quote Link to post Share on other sites
Guest ntc Posted April 23, 2015 Report Share Posted April 23, 2015 Thanks Niall.None of the hoses are twisted or compressed its just the angle of the photo. I'll try replacing the hose from the tank as the tap could be a restriction. Still bemused by the fact that compressing the outlet from pump to tank increases pressure to 120 psi.If the pump isn't man enough or lacks flow why would compressing outlet in create pressure at MU ? Lift the pump upright and in the wheel arch,running out of ideas here Robin but will ask somebody on Sunday who will know. Quote Link to post Share on other sites
bluebob Posted April 23, 2015 Report Share Posted April 23, 2015 Hi Robin A friend of mine had very similar issues we found the problem was restricted fuel flow from tank to pump we increased pipe size and drilled out tank connection point run the supply pipe in 8mm copper through the largest filter we could find (ford escort xr3i) drilled one end out to give maximum flow rate run the system through a bosch pump running at 108lb had no trouble since even taking above the maximum rev range , one over thing that maybe worth checking is you have the right filler cap as I had a problem with vacuum wrong cap supplied by merchants hope this helps Bluebob Quote Link to post Share on other sites
bluebob Posted April 23, 2015 Report Share Posted April 23, 2015 Hi Robin Had a friend who had similar issues we found the problem was due to flow restriction from the tank to filter , so we drilled out the tank connector run a new 8mm copper supply pipe from the tank the biggest filter we could find (escortxr3i) drilled the end out to accommodate the supply pipe run the pump at 108lbs to maximum revs had no issues since, as you have spent time and funds did you replace fuel cap if so check you have the right one as I had a issue caused by vacuum due to wrong cap supplied by merchant. hope this helps Bluebob Quote Link to post Share on other sites
Peter Cobbold Posted April 23, 2015 Report Share Posted April 23, 2015 . Have done 3k miles with this setup , no overheating of pump etc. And it would pull OK over 3000rpm for those 3k miles? - the fault is new?? Quote Link to post Share on other sites
RobinTR6 Posted April 23, 2015 Author Report Share Posted April 23, 2015 Yes, all fine till recently.Had a load of aggro when first rebuilt but that's to be expected.Originally a carb yank motor. Quote Link to post Share on other sites
Peter Cobbold Posted April 23, 2015 Report Share Posted April 23, 2015 Yes, all fine till recently. Then I doubt very much it's pipes, tap, or other non-wearing item. Could be filter element. IIRC there was a thread a year or more ago about CAV filters sold as petrol-safe being actually only diesel-safe..or maybe not ethanol safe. They were coming unglued at the seams ????.... hazy memory. Peter Quote Link to post Share on other sites
RobinTR6 Posted April 24, 2015 Author Report Share Posted April 24, 2015 Given electrics same and everything else unchanged the it can only be filter or pumps.Seems unlikely that both reconditioned units have failed tho. I'll try another filter grrrrrrrr. Quote Link to post Share on other sites
Peter Cobbold Posted April 24, 2015 Report Share Posted April 24, 2015 Has the old filter broken up? If so debris might be causing the rpv to fail to shut fully, and isnt there a thimble filter protecting the MU to check. Peter Quote Link to post Share on other sites
RobinTR6 Posted April 24, 2015 Author Report Share Posted April 24, 2015 Just been talking to 'The man', getting another PRV just in case. Next stop is the filter, luckily have a replacement so will try that. If neither that nor the PRV cures it then it must be the pump. I'll provide an update later this weekend assuming the replacement PRV arrives tomorrow. Thanks all.(neil will also have a go at moving pump around) Quote Link to post Share on other sites
RobinTR6 Posted April 25, 2015 Author Report Share Posted April 25, 2015 Tested output from pump to tank, about 1/2 litre/minute, about half the norm. Points to lack of fuel to pump. Swapped filter, pressure rose to about 100 from 80/90 psi for 5 secs then wailing like a banshee.Wired tank direct to pump, ie no filter, no better. Not filter then. Given I've only played with filter today the pump is now very noisy and pressure now fluctuating...... Thinking cap . I'll retry eyerything from tank in case I've cocked up. Quote Link to post Share on other sites
TR NIALL Posted April 25, 2015 Report Share Posted April 25, 2015 Looks like the Pump or the Plumbing is your problem,can you rig up a temporary Bosch Pump. Quote Link to post Share on other sites
Peter Cobbold Posted April 25, 2015 Report Share Posted April 25, 2015 (edited) I reckon air got in when you swapped the filter. Air is trapped below the pump - the air floats up but the fuel flow is trying to push it down. Now there's air in the gears and it screams. Replumb so the fuel flow through the pump is upwards, then the air will be pumped out of the system with the fuel. Edited April 25, 2015 by Peter Cobbold Quote Link to post Share on other sites
openroad Posted April 26, 2015 Report Share Posted April 26, 2015 Robin old mate, this all smacks of the conversations we had about a year ago, we were both having the same problems then ! i think we both solved it then with rebuilding or re-newing the PRV, I know That Neil was very patient with us both. Good luck this time, By the way i think i owe you £20. Cheers, Conrad. Quote Link to post Share on other sites
RobinTR6 Posted April 26, 2015 Author Report Share Posted April 26, 2015 Conrad, thanks, what's the £20 for ? I'll trade it for a spare part. I'll ring you. I'm waiting foranothrPRV from Neil. I've completely stripped pi feed, pump, filter prv all removed and on bench with pipework. I'll check it all and refit......... Quote Link to post Share on other sites
ijonsson Posted April 26, 2015 Report Share Posted April 26, 2015 Conrad, thanks, what's the £20 for ? I'll trade it for a spare part. I'll ring you. I'm waiting foranothrPRV from Neil. I've completely stripped pi feed, pump, filter prv all removed and on bench with pipework. I'll check it all and refit......... ... and checked that the tank is free from debris? Quote Link to post Share on other sites
RobinTR6 Posted April 26, 2015 Author Report Share Posted April 26, 2015 Update, everything removed stripped checked.All OK including plumbing. Checked flow return to tank, now seems OK, 1 litre in 2 minutes, in spec according to Roger Williams book. New filter in , Delphi 296 , pump now not screaming. However pressure won't increase so must be pump or PRV....tried 2 of each with same result. Quote Link to post Share on other sites
marko Posted April 29, 2015 Report Share Posted April 29, 2015 What happens when you connect your fuel pressure gauge and adjust the PRV....?? The fuel pressure gauge should be connected at the metering unit end. It should be set to 106 PSI constant - at tickover and with revs on..... If not then the car will not perform properly.... If the pump is screaming then its not getting enough fuel.... I wouldn't have my pump mounted sideways..... Quote Link to post Share on other sites
RobinTR6 Posted April 30, 2015 Author Report Share Posted April 30, 2015 (edited) Marko et all, latest is pump has been tested as has PRV on test rig and all OK. To answer your questions,no amount of adjustment at prv raises the pressure above 85/90 at MU. Pressure gauge take off at MU, with glycerine filled gauge. Pump does not scream, sounds normal. Pump tried in boot, upright, upside down, sideways, no difference. Been advised to check vacumn hose from inlets, done. Have stripped all pipework from prv to MU, checked, blown with compressed air, nothing. MU filter also removed and checked, nothing there either. I'll check ignition , its all dizzy doctor bits so should be OK. Hope to get pump back from test in the next day or so, will try with a feed from another source, i.e. not tank in boot.Have already tested all pipework 5/16 standard from tank to filter and from filter to pump, includes new filter. In addition return feed from prv to tank is 1 litre in 2 mins which according to Roger Williams book shows flow to pump is ok. The puzzle is still why I can't get the pressure to 105...... Edited April 30, 2015 by RobinTR6 Quote Link to post Share on other sites
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