Talbot Posted June 11, 2018 Share Posted June 11, 2018 Could you do with some taller gearing in top? Nearly 4000rpm for 70mph must sound a little strained. The fuelling issues you're having all sound remarkably similar to the fuel starvation issues I had with a Rover SD1 many years ago. Have you considered changing the ticker pumps for a single pump from a fuel injection car? Their flow is much more than a ticker could ever achieve (2L/min is quite common). Link to comment Share on other sites More sharing options...
mat_the_cat Posted June 11, 2018 Author Share Posted June 11, 2018 Yeah, the gearbox is a tad short, even with the highest ratio Cortina axle available. I do have an idea though...http://autoshite.com/topic/15643-korean-cortina/?p=1288567 The fact that I've had two years running without fuel starvation says that it *should* be OK if functioning correctly, although having said that I think the needles are still a bit lean at the top end. As I've got a fuel pressure regulator and return, I guess an injection style pump would function fine, and give plenty of margin for error. Link to comment Share on other sites More sharing options...
mat_the_cat Posted June 14, 2018 Author Share Posted June 14, 2018 Nope, new fuel filter made no difference (this is back with the original pump only). Even temporarily took out the filters, with no improvement. The only things left to rule out are the fuel pressure regulator, and the pump itself. The only things which have improved it significantly are blanking off the return, or doubling up on the pumps. I reckon that if the regulator was at fault, two pumps wouldn't make a difference so inclined to think that the pump is failing. Back in 2016 when I relocated the pump to the boot, I had a suspicion that *something* had deteriorated, as I never suffered starvation for the previous two years. So it could well be the flow was starting to drop off then, exaggerated by the heat with the pump in the engine bay. It's a fair old drive to anywhere I can test full throttle for a long period, so I haven't had chance to bypass the regulator. And off on holiday tomorrow so will have to wait till I get back. I think I'll order a new pump to be waiting for me when I get back, so if it's not the regulator I at least can bung the new pump on in time for FOTU. Talbot 1 Link to comment Share on other sites More sharing options...
spartacus Posted June 14, 2018 Share Posted June 14, 2018 Where in the fuel circuit is the pressure regulator? Link to comment Share on other sites More sharing options...
mat_the_cat Posted June 14, 2018 Author Share Posted June 14, 2018 In the engine bay, just before the fuel filter. Why do you ask...? Link to comment Share on other sites More sharing options...
xtriple Posted June 15, 2018 Share Posted June 15, 2018 Does it have a vented tank? Possibly blocked? Talbot 1 Link to comment Share on other sites More sharing options...
Rocket88 Posted June 15, 2018 Share Posted June 15, 2018 Out of interest, what carb are you using? Link to comment Share on other sites More sharing options...
spartacus Posted June 15, 2018 Share Posted June 15, 2018 It should ideally be in the return pipe. You're regulating the available pressure to the carb, so it needs to be after the carb, not before it. doubleyeller 1 Link to comment Share on other sites More sharing options...
Talbot Posted June 15, 2018 Share Posted June 15, 2018 It should ideally be in the return pipe. You're regulating the available pressure to the carb, so it needs to be after the carb, not before it. Putting the fuel pressure regulator in the return line will mean the carb sees full pressure from the pump.. the whole point of the pressure regulator is to prevent that. My money is (now) on a failed/blocked/bunged up pressure regulator. Or at least it will be until Mat comes back saying he's bypassed it and it's no better. After that I'd be looking at failing pumps. Link to comment Share on other sites More sharing options...
Talbot Posted June 15, 2018 Share Posted June 15, 2018 It's a fair old drive to anywhere I can test full throttle for a long period, Left-foot-brake while at full throttle? Not ideal I know as you'll get nice warm* brakes quite quickly, but would enable testing locally. mat_the_cat 1 Link to comment Share on other sites More sharing options...
mat_the_cat Posted June 15, 2018 Author Share Posted June 15, 2018 My money is (now) on a failed/blocked/bunged up pressure regulator. Or at least it will be until Mat comes back saying he's bypassed it and it's no better. After that I'd be looking at failing pumps.You might be right regarding the regulator! My logic is that if I bypass it and the problem goes away, I know that in theory the pump output pressure should be just about ok to feed the (Stromberg) carbs. I could then return the new unused pump for a refund. Better that than needing a pump and not being able to get one in time! Link to comment Share on other sites More sharing options...
spartacus Posted June 15, 2018 Share Posted June 15, 2018 Putting the fuel pressure regulator in the return line will mean the carb sees full pressure from the pump.. the whole point of the pressure regulator is to prevent that. My money is (now) on a failed/blocked/bunged up pressure regulator. Or at least it will be until Mat comes back saying he's bypassed it and it's no better. After that I'd be looking at failing pumps.No, it won't, it'll see the pressure that the regulator is set at, any excess pressure goes back to the tank. If, for example the reg is set to 10psi that is what it will allow in the fuel circuit up until the reg. Fluctuations should only be very slight. This allows fine tuning of carbs with jets, emulsion tubes etc. If the reg is before the carbs then each time there is a significant demand for fuel then the fuel lines may be getting sufficient flow but the pressure may fluctuate, making accurate tuning difficult.This particularly applies to SU's which are very sensitive to fuel pressure. Having said all that, the car appears to have run well for several years, so it may not be the issue. ETA. I'm assuming there is a fuel return fitted. If not then the only way to regulate the fuel pressure is to 'dead head' it by fitting a reg before the carb, as Talbot says. This is not ideal and especially not for an aftermarket pump feeding an SU. Link to comment Share on other sites More sharing options...
Talbot Posted June 15, 2018 Share Posted June 15, 2018 Ah.. I see your point now.. it depends if it's the type of pressure regulator which regulates upstream pressure or downstream pressure! If it's the type that regulates upstream pressure by spilling excess pressure downstream it needs to be in the return line. If it regulates downstream pressure by simply restricting flow and opening to replenish downstream pressure, then it needs to be in the feed line. Over to Mat to determine which type it is... Link to comment Share on other sites More sharing options...
Rocket88 Posted June 15, 2018 Share Posted June 15, 2018 You might be right regarding the regulator! My logic is that if I bypass it and the problem goes away, I know that in theory the pump output pressure should be just about ok to feed the (Stromberg) carbs. I could then return the new unused pump for a refund. Better that than needing a pump and not being able to get one in time! I know it's teaching you how to suck eggs but,,,,,,,,,,,,,,,,carb diaphragm ? [ Common Stromberg fault] Ever considered a Holley 390................work really well on Rover 3.5 engine Link to comment Share on other sites More sharing options...
mat_the_cat Posted June 16, 2018 Author Share Posted June 16, 2018 I am considering a carb swap, but to my mind the symptoms really do fit starvation. It's fine, right until the moment when I assume the float bowls run dry, then I need to ease off to allow them to fill. Then fine, and repeat when I floor it. Thinking of the Edelbrock 4 barrel carb though, especially if we have a trip over to the States... Not sure which regulator I have, and any experimenting will have to wait for a few weeks. Link to comment Share on other sites More sharing options...
Rocket88 Posted June 16, 2018 Share Posted June 16, 2018 Holley 390 ideal for Rover V8......smallest Edelbrock tends to over fuel .............. mat_the_cat 1 Link to comment Share on other sites More sharing options...
spartacus Posted June 16, 2018 Share Posted June 16, 2018 If you do go down the carb route then as has been mentioned a Holley is the way to go. Or maybe a Carter, if there's a small enough model, although I have a feeling the Edelbrock is a license built Carter. Link to comment Share on other sites More sharing options...
Talbot Posted June 17, 2018 Share Posted June 17, 2018 If you do go for a crab change, then there is a garage I can recommend where they can do a rolling road session to set up and jet the carb so that it's in tune throughout the rev and load range. The guys there know more about setting up carburettors than anyone I've ever seen before. Also, it's only about £100 (or at least used to be) Unfortunately, it's in somerset. Nice drive out though.. Link to comment Share on other sites More sharing options...
mat_the_cat Posted July 4, 2018 Author Share Posted July 4, 2018 I whipped out the pressure regulator this afternoon and can say that the problem appears to have gone! Certainly for as long as my bottle held out, full throttle was achieved with no starvation I did phone up Speedflow beforehand, to enquire about pumps and had some useful advice. The guy I spoke to was almost trying to talk me out of the sale, at least until I had been able to do more diagnosis. One suggestion was to monitor the fuel flow both before and after the 1mm return restrictor, to get an idea of the actual available flow to the carbs - which would better enable me to spec the right pump if required. I've managed to find the specs for the pump I have:https://www.durite.co.uk/itm/Diaphragm-Pressure-Fuel-Pump-12-24V/12V-Electronic-Diaphragm-Pressure-Fuel-Pump-Suction-Version/029612 which appears as though it should flow more than enough fuel, but the pressure is less than I thought so likely doesn't need a regulator anyway. FOTU here we come! oldcars, BorniteIdentity, RayMK and 3 others 6 Link to comment Share on other sites More sharing options...
Tickman Posted July 4, 2018 Share Posted July 4, 2018 I whipped out the pressure regulator this afternoon and can say that the problem appears to have gone! Excellent news.Such a tidy install, I'm glad it is behaving as it should. Link to comment Share on other sites More sharing options...
mat_the_cat Posted August 9, 2018 Author Share Posted August 9, 2018 I made it to and from FOTU, including picking up a very rare undertray for the LT which only *just* fitted across the back seat, with the seat base removed! In the Field of Dreams: We had a brief but heavy rain shower, so I attempted to show some beading: The engine attracting interest! It's strange really, in that I've done all the work to the car with absolutely no intent to impress anyone, not to fit into any 'scene', just to go with exactly what *I* wanted. Yet I do get a bit of a buzz seeing people interested in it.I was telling one guy the story behind it whilst stood at the back of the car, and he told me it was a great bit of history. But then he walked round to the front, looked at the engine and burst into a huge grin and a "What the fuck?" So maybe there is a part of me which enjoys showing off? On the way back into Wales: It behaved well, with no trace of starvation so I think I can relax a bit now. Still haven't attended a Shitefest in it without worry though! Next year...? The MOT was due this weekend, so I phoned up my local garage to book it in."Have you got a slot free this Wednesday, if I leave it with you all day?""No problem, can I take the car details?""Yes, it's a Hyundai Stel-""Oh hi Mat, how are you doing?" They must remember me for some reason? Anyway, no problems with the MOT yesterday, but it rewarded me with an intermittent fuel gauge AND speedometer, so more tinkering time is needed if I'm not to risk running out of fuel. Scruffy Bodger, Tickman, Conrad D. Conelrad and 15 others 18 Link to comment Share on other sites More sharing options...
Felly Magic Posted August 9, 2018 Share Posted August 9, 2018 Nice result there Mat, somehow I think you may have the only Hyundai Stellar in Welshland Link to comment Share on other sites More sharing options...
bezzabsa Posted August 10, 2018 Share Posted August 10, 2018 Just read this from start to finish.... Great to see a fairly odd old car get some love.. BUT Why not SU's on the V8??and did you consider dropping the 4.0 engine in ?? and also , the exhaust is probably sapping a good few HP, as the earlier ones weren't the best for extraction of spent gasses..I can appreciate the space problem, but a 'one off' set of headers can be had for quite reasonable these days..also quite a few V8 kit cars about running good systems, so a trawl of the web may help.... Excellent work so far, and Nice to see a Yam Yam bus pass found in the Stellar too Burnside and mat_the_cat 2 Link to comment Share on other sites More sharing options...
mat_the_cat Posted August 10, 2018 Author Share Posted August 10, 2018 Why not SU's on the V8??and did you consider dropping the 4.0 engine in ?? and also , the exhaust is probably sapping a good few HP, Simple answer is that the Strombergs were new and unused, and free! Although I did swap a crate of beer for them. I don’t think they’re a ‘bad’ carb as such, but SUs have a much wider range of needles available for them. I don’t think the manifolds are the best, being a log style – but Rover IIRC claimed around 160bhp for the P5B so they can’t be dreadful. A new set is on the dream list, if anything which fits into the available space can offer a significant improvement for the cost. Part of me wonders if I’d get more enjoyment just blowing the money on fuel… I did and still do wonder about a larger capacity engine, but that particular 3.5 has been through a lot with me – it was the first engine I ever took out of a car, I’ve dragged it through 4 house moves, and it lived outside under a tarpaulin for a few years. And then it was the first engine I’ve totally rebuilt, so to get rid of all that history seems a shame. John F, RobT, Tickman and 8 others 11 Link to comment Share on other sites More sharing options...
mat_the_cat Posted August 13, 2018 Author Share Posted August 13, 2018 I started to investigate the fuel gauge and speedo at the weekend, but on putting the electronic speedo drive into test mode found that the needle moved fine, so I suspect the problem may lie with the speed signal. There is a flashing LED on the unit to signal when it has received a pulse; problem is this is impossible to see whilst driving unless I rig up a camera. As you can also see, the fuel gauge is now working so I have to wait for that to fail before I can investigate! mrbenn and Talbot 2 Link to comment Share on other sites More sharing options...
dollywobbler Posted August 14, 2018 Share Posted August 14, 2018 Someone left a comment on the video about this asking why it hadn't been modified for power. I patiently explained that power isn't really the point. It sounds awesome and probably has twice as much torque as it would have had when new. It's fine as it is I reckon! michael t, mat_the_cat, Lacquer Peel and 1 other 4 Link to comment Share on other sites More sharing options...
mat_the_cat Posted August 28, 2018 Author Share Posted August 28, 2018 The fuel gauge is now working - was just a poor contact so an easy fix. The speedo drive is still under investigation! I jacked a rear wheel up last week and let the engine idle in gear while I checked the drive unit for the flashing LED denoting a signal. Nothing. So it looks as though there is no signal being generated until some time into the journey. To further prove this I connected my rather elderly 'scope up to the sensor, and went for a drive. Amazingly, the internal (Ni-cad!) battery still holds a charge so I was able to check out the signal on the move. With the speedo working, I get the pattern below: I've not yet been able to monitor with the speedo inoperative, but would expect a flat line like in the first photo, although it's possible that under certain situations, electrical noise could swamp the signal, hence the reason for carrying out the checks. Skizzer, Lacquer Peel, Talbot and 2 others 5 Link to comment Share on other sites More sharing options...
mat_the_cat Posted September 6, 2018 Author Share Posted September 6, 2018 Right, during the period of time there is no speedo, there is no signal from the sensor, and as a double check (could have just done that anyway!) at that time it is infinite resistance. New one on the way so should be an easy fix. Surprising that it starts off open circuit and then begins to work - normally such sensors fail the opposite way round. I went out for a run in the hills earlier this week, and the light/scenery was rather nice so I took a few photos. This was on getting back to the car...twilight, and quite a welcoming warm interior as the temperature was dropping rapidly. Exiled_Tat_Gatherer, Banger Kenny, Zelandeth and 7 others 10 Link to comment Share on other sites More sharing options...
stuboy Posted September 6, 2018 Share Posted September 6, 2018 love the normalness with grunt under the bonnet mat_the_cat 1 Link to comment Share on other sites More sharing options...
tooSavvy Posted September 7, 2018 Share Posted September 7, 2018 Y..M..C.. Nice piccie Link to comment Share on other sites More sharing options...
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