Darren Groves Posted July 6, 2017 Share Posted July 6, 2017 Since my EFI conversion I have been using a Sytec Adjustable Fuel Pressure Regulator (this one). Went off in the car today and it felt a little reluctant when cold, then better when warm but not right. Got to where I was going, checked the gauge on the regulator and it was way down under 0.5bar. Slackened off the lock nut, wound the pressure up as far as it would go and it just about managed 3bar, which is where it was first set. I start tapping the regulator and the pressure started creeping up, wind it back down to 3bar and repeat the process until the adjuster is roughly back to where it was and the pressure doesn't increase with the tapping. Locked the adjuster and kept testing, all fine, drove home and still at 3bar. Seems to have been a bit of a hiccup with the regulator, but doesn't really instill me with confidence. In my experience if something goes wrong then fixes itself, it's just waiting to go wrong again, or am I worrying unnecessarily? I avoided the cheap eBay specials and thought Sytec was OK for quality? If it does it again I'll get something different, but any suggestions? It'd need to be one with the 2 barbs so it's a straight swap, Weber do both fixed pressure & adjustable, they OK or something else out there you'd recommend? Darren Link to comment Share on other sites More sharing options...
oldtuckunder Posted July 6, 2017 Share Posted July 6, 2017 Don't know about EFI regulators, but on the carb ones like Filter King (which are operating at lower pressures) they recommend that the gauges are not left permanently plumbed in as I think they are the weak point. Alan Link to comment Share on other sites More sharing options...
Nick Jones Posted July 6, 2017 Share Posted July 6, 2017 Might just have been a bit of cack on the seat - though no doubt you have a filter fitted? I think Sytech are ok-ish by reputation and at that price it shouldn't be complete rubbish! I've always used OEM Bosch fixed pressure ones - harvested from scrappers..... Never found a 3 Bar one with hose-tails both sides though. I do tend to share your concern that it might happen again. Nick Link to comment Share on other sites More sharing options...
Darren Groves Posted July 6, 2017 Author Share Posted July 6, 2017 There's a strainer/gauze on the pump pick-up and I have a inline filter also, so any crud should get caught. It was just odd that tapping the regulator body got the pressure back up in small increments, will just have to keep an eye on it. If it happens again I'll try the Webcon fixed pressure unit I think. Did you fit an inline pressure gauge to test the pressure of yours or just take it that is was accurate? Darren Link to comment Share on other sites More sharing options...
Nick Jones Posted July 6, 2017 Share Posted July 6, 2017 I did run with a gauge for several months when I first built the thing and it just seemed to work as it should so I took it off. I did refit the gauge briefly a while back when the pump was very noisy and it was still working as intended (fitted new pump instead) so took it off again. Nick Link to comment Share on other sites More sharing options...
Darren Groves Posted July 8, 2017 Author Share Posted July 8, 2017 I rechecked the pressure this morning and it's now up at 3.5bar, so have tweaked down again to 3bar, so seems it's struggling to keep a steady pressure. I have decided to buy the Webcon 3bar fixed pressure regulator just for peace of mind. Darren Link to comment Share on other sites More sharing options...
Darren Groves Posted July 9, 2017 Author Share Posted July 9, 2017 The new regulator is on the way, but before that arrives I was off to Powderham Historic Gathering today so a round trip of around 120 miles. Car was running very poorly when cold, got better when warm but lacking power, but done the round trip OK. On our return the exhaust tailpipe was sooty as were all the plugs, so have quickly plugged in the laptop to see that it's definitely way too rich now, the AFR at idle was between 10~11:1. I have loaded various recent tunes and imported the backed up AFR & VE tables from just after RR that were giving good AFR readings before, but still the same. Even though the Regulator gauge was reading 3bar I lowered the pressure to <2bar and no real change, disconnected air filter just in case it was clogged and just the same. Checked Air & Coolant temps and they seemed fine, WUE @ 100% over 60°C. Is there anything I missing here, any reason why it would just go way too rich when nothing has changed? Darren Link to comment Share on other sites More sharing options...
Nick Jones Posted July 9, 2017 Share Posted July 9, 2017 Given recent history I'm inclined to suspect anything to do with the pressure regulator, though would have to concede that it's odd that the pressure gauge was still showing the correct pressure and could be varied...... Is the return line flowing ok? Otherwise, assuming you are running a MAP sensor as your load indication, anything that causes that to read higher pressure than real - so an air leak in the line to the sensor would do this. If you are running TPS as your load indication then you should check this is working properly and do a calibration check on it. I suppose also if the IAT or coolant sensors are telling the ECU that things are much colder than they really are, this would also cause rich running. Nick Link to comment Share on other sites More sharing options...
Darren Groves Posted July 9, 2017 Author Share Posted July 9, 2017 IAT & Coolant both looked normal and no reason to think the fuel return is an issue though I will check. MAP reading was around 40kpa at idle IIRC which I think is where it's always been and TPS %'s look fine. The new regulator should land tomorrow and it's a fixed 3 bar, so here's hoping it's the problem. Darren Link to comment Share on other sites More sharing options...
Nick Jones Posted July 9, 2017 Share Posted July 9, 2017 All seem to checkout ok........ I also hope it is the fuel pressure as I'm not sure what else to suggest! Nick Link to comment Share on other sites More sharing options...
Darren Groves Posted July 10, 2017 Author Share Posted July 10, 2017 Slightly frustrating day today in that the car was running this morning, albeit not that great, to not starting this afternoon. So I know it's not the Fuel Pressure Regulator or pump, both swapped out an made no difference. The barbs on the plenum for FPR & MAP Sensor were both a little loose, so added some threadlock/sealer and tightened, but still no difference, fuel return working fine. Reloaded the firmware several times, even went back to the original version, then back to the latest with the same results. Just for the experimental purposes I highlighted all the cells on the VE table and brought them down, idle & AFR improved but looked a little erratic. No point in try tune out what appears to be a mechanical problem. I am now working on the basis it could be a weak spark due to a failing EDIS, Coil Pack or Crank Sensor, the weak spark leaving un-burnt fuel and giving the rich AFR Reading. Thought I'd check voltage at the Coil Pack & EDIS first and I had nothing, after some head scratching as I then realised I'd pulled the spade connector of the live feed . So with that reconnected I tried to start her up and nothing and now there was no spark..... . I maybe clutching st straws but I'm hoping the failing item has now failed completely, unfortunately my spare EDIS, Coil Pack & Sensor were at home and the car was at the workshop....job for tomorrow. I am supposed to be heading up to Sherborne this weekend in the Herald, but looking like the SLK will be called into action. Darren Link to comment Share on other sites More sharing options...
rogerguzzi Posted July 10, 2017 Share Posted July 10, 2017 Hello Darren If it turns out to be the Edis or coil pack I would change to the VW type coil pack with built in driver! Genuine Bosch ones are £100+ but the copies are as low as £10. My first one has done 3500+ miles now with no trouble and the spare in the boot does not take up much room along with a crank sensor! Any more than that and it is the ECU(you do not have the limp mode anymore if ECU fails) I may look for a spare TPS sensor to carry? Roger Link to comment Share on other sites More sharing options...
Darren Groves Posted July 10, 2017 Author Share Posted July 10, 2017 Hi Roger, I'm not adverse to moving away from EDIS & Coil Pack, but I do have a spare of each so they will be staying for this summer at least even if they are the cause of the problem (I hope they are!), they do date back to my Megajolt days so have done around 12-15k miles with no trouble. I really need to get the dash off the car so I can sort out the spaghetti behind, so removing the EDIS would simplify just a little, job for the winter. Darren Link to comment Share on other sites More sharing options...
rogerguzzi Posted July 10, 2017 Share Posted July 10, 2017 Hi Roger, I'm not adverse to moving away from EDIS & Coil Pack, but I do have a spare of each so they will be staying for this summer at least even if they are the cause of the problem (I hope they are!), they do date back to my Megajolt days so have done around 12-15k miles with no trouble. I really need to get the dash off the car so I can sort out the spaghetti behind, so removing the EDIS would simplify just a little, job for the winter. Darren Hello Darren My main reason to not use Edis was that I can get replacement parts anywhere we are even foreign places it is common stuff Plus it does get rid of a few cables and plugs! Roger Link to comment Share on other sites More sharing options...
Nick Jones Posted July 10, 2017 Share Posted July 10, 2017 You could try turning off the O2 sensor (or giving it 0 authority so it can't change anything) just to make sure it is not seeing an air leak or misfire as lean running and richening everything up too much? Nick Link to comment Share on other sites More sharing options...
Darren Groves Posted July 10, 2017 Author Share Posted July 10, 2017 Thanks Nick, will take a look at that is the replacement EDIS/Coil Pack doesn't help. Darren Link to comment Share on other sites More sharing options...
Darren Groves Posted July 11, 2017 Author Share Posted July 11, 2017 The non-starting last night was fatigue in the cables to the coil pack just before the plug, a new plug and lengths of cables fixed that, I tried the spare coil pack & EDIS and there was no difference to the rich running. I could feel the flow on the return, but it was a fair bit weaker the the feed, but as the original regulator kept reporting low pressure I thought I'd look at the hose between the rail & regulator. I unscrewed the 90° elbow to find a length of plastic sticking out, so I pulled it out to find this: This plastic bag with the O Ring in the image also contained the AN fitting that I took to a local engineer so he could square off the end of the fuel rail and tap a thread. When I got it back he has screwed the AN fitting in and must have pushed the bag & O Ring up the bore of the fuel rail, not knowing it was there I then fitted the fuel rail. So that has been stuck in the fuel rail for over 1000 miles and must have dislodged last week, then stuck in the elbow causing back pressure in the rail and the injectors to over-fuel. Removed the random object, started her up and she runs sweet again..... Darren Link to comment Share on other sites More sharing options...
rogerguzzi Posted July 11, 2017 Share Posted July 11, 2017 Hello Darren Well that is different? Roger Link to comment Share on other sites More sharing options...
Nick Jones Posted July 11, 2017 Share Posted July 11, 2017 Tricky diagnosis........ but easy fix, which is nice Nick Link to comment Share on other sites More sharing options...
Darren Groves Posted July 11, 2017 Author Share Posted July 11, 2017 Silly mistake really, I should have checked when I got it back from him, but was relived I found something definitive. Plus the digging around uncovered a problem with the coil pack wiring so that prevented a future problem. It cost me the price of a new FPR, but the new one is neater and fits better so not too unhappy about that. It was looking like the weekend in Sherborne was going to be in the SLK, but back to the Herald now :-). Darren Link to comment Share on other sites More sharing options...
Nick Jones Posted July 11, 2017 Share Posted July 11, 2017 That's local to me and normally I'd be going, but will be in Majorca this time. Sorry to miss you. Watch out for my friends Andy Topp (damson TR6 with EFI or Mk 1 saloon with V8) and Martin Cameron ( well used mk2 vit convertible Ian dark blue) and don't believe anything they say about me unless it's good! Nick Link to comment Share on other sites More sharing options...
Darren Groves Posted July 12, 2017 Author Share Posted July 12, 2017 don't believe anything they say about me unless it's good! Haha, will try and find them and say hello. I went last year for the first time, traffic was horrendous trying to get in and it was baking hot even early on. It's a 2 day event this year, so hopefully a bit easier to get in. Enjoy Majorca! Darren Link to comment Share on other sites More sharing options...
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