ramon alban

Comprehensive RV8 Electronic Ignition PDF's available from these links Here for Rover SD1 V8 Electronic Ignition - Description and Analysis Here for Rover SD1 V8 Electronic Ignition - Components and Testing owners moggydawed by Electronic Ignition can redress the balance and, hopefully, report back any O's & E's. Ramon www.vintagemodelairplane.com

Helo Onne, Only have experience with earlier SD1 system, but two possibilities come to mind: # The ignition amplifier is dying, when hot and killing the ignition, only to recover its vitality when cold and temporarily give you back the missing sparks. # Ignition amplifiers have a finite lifetime typically in the range 60,000 - 100,000 miles Alternatively # Your tacho dying as engine stalls suggests an intermittent connection from Coil Negative directly to the Tacho and via a Trigger Resistor to (normally) pin 1 of the ECU. # Check all the White/Black wiring connections there-abouts for integrity, corrosion, breaks. # Hopefully this circuit should be similar to yours. Forgive me if these are false trails. Ramon www.vintagemodelairplane.com

What the heck happened after this? Repeat, well at least it stays running at a reasonable rpm now, If by fiddling with the ECU multiplug the problem virtually disappeared and it has since returned, my conclusion would be to revisit the same place again. Are you able to see any damaged contacts on the multiplug. Also they lose their springynees and can be tweaked/adjusted with a wooden kebab stick. If I misunderstood the above quote, I apologise, but I cant see where it says the variable rpm was still a problem, then? So it must have returned - worth looking at that solution again, methinks.

Niki, You need to check the plug condition and report back, to assess how bad the mixture problem is? Your trigger signal is working OK otherwise the engine would not run at all. The ECU fires the injectors each bank of four alternately. Read the articles on my website to understand everything. The reason your tps is not getting to 4.3 volts is EITHER 1 the wrong TPS with 105 degrees of rotation (not a serious problem) OR 2 there is a mechanical restriction not allowing throttle to open fully. To "think" the FPR is not working is an important observation and could be your problem, but you must measure the fuel pressure as specified in the FPR article on my website. The fuel pressure should vary from 26 - 36 psi depending upon throttle activity and engine load. The article explains how/why. Is the FPR vacuum tube OK? Did you actually measure the temp sensor reading at the ECU multiplug? If not, your ECU may not be seeing the sensor correctly. Regarding broken ignition - ignore for the time being, your engien runs, but with a mixture problem not an ignition problem.

OK! At the getgo of these systems, Bosch/Lucas had to devise a way of making a combustible mixture available when the engine was on Overrun (typically, fast downhill with throttle shut) and by using the very high vacuum generated on overrun, open a valve to allow in more metered air and thereby correct the mixture, thus averting unburned fuel popping and banging in the v. hot exhaust system. Time moved on and Rover decided to eliminate the problem in later systems, like yours, by having the vacuum operate a vacuum controlled relay to cut the engine running signal from coil neg to pin 1 of the ECU. Now with therunning signal absent, the injectors never opened on overrunn so no uncombusted fuel passed thro' into the exhaust. Same result, no popping and banging and a bonus of slight improvement in emissions and economy. Its not quite as simple as it sounds, indeed the science behind it is quite deep, but I have made a decent stab at a full explanation. Most owners dont give a damn about this but when things go wrong, as they did with you, an understanding of whats happening brings clarity to the issue - so read this study at your peril: http://www.vintagemodelairplane.com/pages/Rover_Technical/Overrun02.html Oops! Your mud covered relay had good reason to croak irrespective of its lightly loaded function. Tee hee!

Hello Niki, # That black smoke without the smell of burning oil is due to rich mixture, I reckon you will find your spark plugs black/sooty too. # The likely cause is the temp sensor or even your replacement resistor is not being seen by the ECU due to a faulty connection from sensor to ECU or a faulty earth connection from the Efi loom to the engine block. # Check you measurements at the ECU multiplug, or simply inspect, clean and carefully fettle the contacts there-in. # All the above is usual suspect number 1. # This essay explains how to perform the tests, but your ECU may be different to the one described: http://www.vintagemodelairplane.com/pages/Rover_Technical/TempSensor01.html Other suspects are: # Faulty FPR causing fuel pressure to remain constantly high. # Vacuum tube not connected to FPR - with likewise effect. # Noisy/damaged throttle pot. # Blocked air filter You might wish to read my essay about diagnosing the colour of exhaust smoke: http://www.vintagemodelairplane.com/pages/Snippets/Smoke01.html Check it out!

Your problem was sequential. Your croaking battery was not well enough to fire the mixture on the first couple of starts, by which time the engine had flooded. Your weak battery now stands no chance but the flooding continues with each attempt to start, Fitting a new battery was never going to work without first unflooding the engine by either cranking with pump disconnected and throttle wide open, OR, cleaning all the plugs before the retry.

Which I guess is pretty much the same as this suggestion: Also, How was it faulty? Not responding to vacuum? Vacuum not connected? Relay contacts permanantly open? Did you destroy a good relay, one wonders? Did you replace the faulty relay or simply join the wires to bypass it? Reason I ask, is, those relays with little or no load, dont usually croak!

Your wet plugs may have been caused by continually trying to start the engine so the cold start injector has been pumping fuel every time the engine cranks. As 'Ally V8' mentioned, a flooded engine is a pig to fire up. If so (and perchance) there may be no evidence that the fuel is coming from the normal injectors. If they are not firing, then there are three possible reason 1 the trigger signal from coil negative to the ECU has not been reconnected 2 the ECU is broken 3 the wiring loom/ECU multiplug connector is not seated or some earth connection is missing, or some other wiring loom issue. For a unique and comprehensive analysis of all the EFI components have a browse thro this archive. http://www.vintagemodelairplane.com/pages/Rover_Technical/EfiComponents01.html

Why? You have almost certainly found the fault, by following the highlighted advice in my first post, #9: If its running at 98% the remaining 2% won't be found inside a fresh ECU. Finish the ECU multiplug cleanup as suggested and move on to an overall health check for your Efi system (used to be known as a tune-up). I have documented fifteen things a boy can do under the psuedonym of eliminating power losses (but, whats in a name?). http://www.vintagemodelairplane.com/pages/Snippets/MorePower01.html Being keen on finding the lost percentage will mean extreme diligence addressing those 15 items. Indeed, with a bit of luck, you'll probably find more than the missing 2%. By its nature, when faced with methodical advice, one is tempted to miss out some steps! If so, think about the young bull who said to the old bull, "Look! There are some cows in the meadow! Let's run down do a couple". The old bull replied, "Nah! Let's walk down and do the lot! Otherwise, you'll never know how much fun you coulda had!"

Any idea what the condition of the spark plugs is like after the engine has stalled?. Check at least one plug from each bank. preferably a couple. Looking for black/wet condition indicating overfuelling. If one side is ok and the other is black/wet then its a cinch for ECU problem. If both sides wet/black, we are still looking for ECU or temp sensor connector probs. Also possible fuel pressure regulator failure, or a really BAD throttle pot. If there is no evidence of black/wet then fuel starvation as mentioned in new posts is a distinct possibility.

Hello Nige, All the above is so very true and even as most of the components themselves were pretty much bulletproof (with a couple of exceptions), the worst enemy of our Flapper systems today is dirt and neglect. As purchased and for several years thereafter original sharp suited owners had their Full Service History, and dependent wholly upon their franchised service agent, the flapper systems held up pretty well, despite the original cost vs quality issues you mentioned. Then the 2nd, 3rd and 4th generation of owners took over, dropped their routine servicing down to brake pads, oil and filters and completely overlooked cleanliness and wiring connector/air pipe security. Thus it came to pass, crudded up throttle and plenum chamber, blocked breather, corroded connectors, split rubber tubes, emerged tenfold, thus our sad/old flapper systems got themselves into a terrible state and started to give up the ghost, ad nausium. Now, all new owners came to believe some sort of black art was required to diagnose fault conditions and all this time fewer and fewer flapper-wise technicians populated the planet. Woe, Woe and Thrice Woe! Now the hobbyists come onto the scene - from 1993, I'm one - and bemoaned a lack of expert help, even then. So for them there was/is really only one solution - DIY and internet forums. To that end, I had to overcome and combine my complete ignorance of motor cars and fuel injection systems with my diagnostic career in hi tech, persuading myself that this could not be rocket science. I just needed an edge. And so it came to pass, I acquired a copy of the LR Technician Training Manual and Video for the Flapper Efi and set my sights of becoming self-sufficient. Without that training manual nothing made sense. It was the key to the door and the bible from which everything else flowed. After the first few years with my car I knew enough to be confident to write it all down again, not in tech training terms, but a changed lingo that the DIY home mechanic could assimilate in Club magazines, journals, etc, all too early for the internet, then, of course. Now, with more knowledge and refinement plus the power of my own website, the end result is what appears on my web pages and, I agree 100% with you - patience, and a structured methodical approach is the key to success for the enthusiastic hobbyist. For those who cant do this thing, it leaves only the expensive scattergun approach to component replacement whilst sadly overlooking 80% of the likely causes, air leaks and connection problems, undiagnosed and still part of the perceived black art. A better alternative to scatterguns is to clearly gather up all the signs and symptoms, state the car and the system, post it all on one of the various available forums (forii?) and let the dogs loose. Trouble is, even when answers seem to be logically analysed and proposed, sometimes an originator reverts to the scattergun, and like an oil tanker on collision course, no amount of pleading can change the turn of events. Its a shame but thats the truth of it.

If, after you have tried a known good working ECU, the fault persists, you may choose to look again at the temperature sensor that has a 80 to 100 degree C resistance of 300 to 150 ohms, and yes, the early flapper engine will fire and run from cold with an open circuit sensor, running progressively more rich up to the point where it croaks, somewhat as you describe in your first post. Surging or hunting is a possible symptom of a fault condition usually induced by a rich mixture occuring somewhere in the warm-up cycle. Mostly at idle, but capable of occuring at higher rpm. It is usually transitory, but when severe, eventually manifests itself in a "surge too deep" where-upon the engine dies. Read about Flapper system Hunting here: http://www.vintagemodelairplane.com/pages/Snippets/EfiHuntingSolutions01.html The ECU can and does play up but it has multiple fail modes so none are particularly "classic" except perhaps gross overfuelling on one bank of four cylinders in which case the engine floods from the getgo. Lets hope it is the ECU, for an easier fix.

George, I am completely mystified by your comment when its been explained with several replies that we are primarily dealing with a temperature related, and possibly intermittant, fault due to dodgy coolant temperature sensor and/or its associated connector and wiring and only as a secondary suggestion, perhaps air leaks might come into play. Yet you have rechecked air leaks and the distributor when there is very low possibility of an ignition fault and totally ignored the prime suspect - Temp sensor and its wiring. Also no feedback from you what is the condition of the spark plugs, a key indicator for mixture problems. Its just occurred to me that you dont have a multimeter or the skills to use one and if that is the case, please either read about using a multimeter here: http://www.vintagemodelairplane.com/pages/Snippets/Multimeter01.html or get some help from someone who can use one.

Hello George, your scattergun approach, replacing all those very robust and expensive components does not generally work. First, I'm guessing its a Flapper AFM System, running on petrol and/or lpg? As you have replaced so many components without success one needs to turn to analysing the symptoms. I'm also pretty sure that upon inspection you'll find the Spark Plugs will be black or wet. Thus, it's clearly a temperature related fault with (assuming) wet/black spark plugs as I describe, so I'll wager its starting to run too rich During and After the warm up process resulting in your reported Hunting, Stalling and Lumpy Combustion process. The problem, therefore, must be the Coolant Temp Sensor or its connections are open circuit causing overfuelling when warm/hot. Just changing a component will not expose dodgy connection problems, so test all the aspects of the CTS and its wiring as per the following link: http://www.vintagemodelairplane.com/pages/Rover_Technical/TempSensor01.html You should be looking for broken CTS connector contacts, broken wire in the Efi loom, dodgy/corroded earth connection on the engine block studs behind and below the L/H rocker cover, faulty connection in the contacts of the ECU multiplug. Fix the latter carefully with a wooden kebab stick. For good measure, and to last a lifetime, clean and spray WD40/Switch cleaner into all Efi wiring loom connectors and fill with vaseline before reconnecting. Regarding air leaks, although unlikely to be the primary cause, they are also a contributing possibility. To run a full set of tests, see here: http://www.vintagemodelairplane.com/pages/Rover_Technical/Plenum01.html Its a sad statistic, approx 80% of all Flapper System faults are due to air leaks and/or electrical connection issues. For more info on the flapper system similar to yours, check out all the Efi system component essays in the Efi archive on my website. In addition you may wish to study an Efi Operations Manual, where the whole kit'n'kaboodle is fully explained. You'll be amazed! If you car is not a 3.5 flapper, None of the above applies. For anyone curious about the common cause of Efi Hunting - look here: http://www.vintagemodelairplane.com/pages/Snippets/EfiHuntingSolutions01.html

Fridge, My drawing applies to the Rover SD1 82-86 systems but I have been using it to illustrate the generic ignition process whenever it seems to meet the OP's queries. You are however right for the period Range Rover System where the Rover SD1 mechanical vacuum overrun valve on the rear of the plenum was replaced by the vacuum cutoff relay interupting the ignition feed to pin 1 and cutting of all injection during over-run. On the Rover SD1, during over-run, the Efi system crudely relied upon some additional air introduced via the mechanical vacuum valve intended to create a combustible mixture from the fuel injected at the throttle idle position PLUS fuel already condensed on the plenum/manifold walls which during over-run immediately evaporates, rather than having the resultant increased quantity of fuel get thro the the exhaust system, unburned, where it causes loads of popping and banging.

Hello Haakon,Here is a generic circuit diagram of a typical (mid '80's period) Rover V8 electronic ignition where the amplifier can be either on the side of the distributor - 35DLM8 - or in an aluminium unit mounted adjacent to the ignition coil - 35DM8. you may not need further info but just in case check out my post on this thread http://forums.lr4x4.com/index.php?showtopic=38631

Hello Taka,This may not be simple enough for you, however, here is a generic circuit diagram of a typical (mid '80's period) Rover V8 electronic ignition where the amplifier can be either on the side of the distributor or in an aluminium unit mounted adjacent to the ignition coil. What follows is an extract from my upcoming ignition system manual describing each component function. Hopefully it will answer the above question satisfactorily. The Basic Electronic Ignition Components and their Functions From battery through to spark plug and beyond, these are the key components involved in generating the bright blue spark that ignites the awaiting air/fuel mixture and they must all work flawlessly for maximum engine efficiency. A Battery in good condition, capable of lighting the blue touch paper even whilst churning a reluctant lump on a freezing cold day. An Ignition Switch with four key positions: 1, Off, 2, Accessories, 3, Ignition On and 4, Cranking. The latter two positions both supply 12 volts to make the ignition circuit come alive. A Distributor with three tasks. 1, Determine the exact moment during the cycle to generate a signal pulse to ignite the touch paper, 2, Route the resulting spark to the right firework, and 3, Advance the ignition timing according to either inlet manifold vacuum or engine speed. A Vacuum Advance Module that senses manifold depression as soon as the throttle plate moves away from the idle position and advances the timing to capture maximum efficiency from the upcoming explosions at low engine speed, then passing over ignition advance responsibility to - The Mechanical (Centrifugal) Advance Mechanism that uses bob weights and springs to control the amount of ignition advance according the engine speed and rate of acceleration. A Magnetic Rotor with eight peaks produces a pulsing magnetic field adjacent to - A Pick-up Coil that generates its own output (like an alternator, so not needing a voltage supply) to send a synchronised sine wave signal through its two electrical connections to - An Amplifier Module already connected between Coil negative and earth that responds instantly to the incoming signal, switching a path to earth for the negative side of - The Coil, actually not unlike a transformer which converts the switched current from the battery into (typ) 30,000 volts capable of bridging gaps of up to 15mm with a bright blue lightening strike. A Condenser (or Capacitor) connected into the low voltage circuit across the coil/amplifier combo to suppress Radio Frequency signals otherwise destined to upset in-car entertainment systems and offend un-Neighbourly soap addicts watching their TV’s down the Eastend. It is also perceived to assist in rapidly collapsing the coil primary voltage for a sharper high voltage discharge. A King Lead connects the high voltage terminal of the coil to the centre turret terminal of - The Distributer Cap that receives and transfers the high voltage discharges to the - The Rotor Arm which allocates the lethal sparks to one of eight turrets connected to - The High Tension Leads with a particular internal impedance, resistance or other RF suppression characteristic, terminating at the prickly - Spark Plugs where a flash of highly charged electrons ignite the expectant air/fuel mixture inside the combustion chambers, such that, under all the various engine conditions, its exact occurrence is determined by - The Ignition Timing, not in itself a component, yet in conjuction with the vacuum and mechanical advance components, the most critical of all the functions, often maladjusted. A Trigger Resistor connects signals generated at coil negative, to Pin 1 of the ECU to notify it the engine is running and please keep injecting fuel until these pulses cease. The same signals from coil negative also go off to the Tachometer to indicate engine rpm and to the Cruise Control over-speed relay for engine protection if the Cruise ECU tries to accelerate the engine when the transmission or gearbox is disengaged. Because the above is a "work in progress", errors and omissions gratefully received.

Gosh, perhaps I meant "nipple ends" -

Hello RT, The high pressure fuel hose is available by the meter from any Yellow Pages fuel injection specialist, typically 8.6mm ID, and you can use simple "P" type fuel hose clips or jubilees. You can see a pair of the "P" clips being used in this image on a water pipe, but they are fine for fuel lines too. Burlen Fuel Systems do hose and clips mail order. Its the swage or bell ends that make it very unlikely to blow off, after all its only about 36 psi going to a maximum of 50 psi if the fuel return line gets blocked.

Hello V8defender90, with the above query and similar enuirey re AFM, plus being new to RV8 Efi you might like to get some basics for Efi under your belt. Unfortunately there does not appear to be a simple explanation to RR models but if you care to read all the stuff on this index, you will increase your savvy on the basic Efi Flapper system. http://www.vintagemodelairplane.com/pages/...mponents01.html By doing so you will be able to follow the answers given on the forum for the symptoms. you report. The analysis you have so far is clearly correct, such that the ignition timing is way off and you need to get it back to specification, but as time goes by, if you are planning to do any DIY servicing on your Efi system you need some basic background info. I understand that a RR document called RAVE has similar info but I find it difficult to follow, myself. Happy reading.

OK. I've been thinking about this from the point of view of the science, and I know you are going to shout at me but just suppose that "Mr Cam Man" had the following experience. His cam lobes wore down to allow a low input charge during induction and an even lower output flow during exhaust. On induction ALL the fuel (because of its proximity to the inlet valve) and not very much air would be sucked in, forming a very rich, near uncombustible mixture swilling around No 1 pot. Then along comes a spark which will have some difficulty getting a proper bang from No1 due to mixture issues. Then the exhaust valve opens just enough to let some badly burned hydrocarbons escape into the real world. And so things continue in the same vein! A misfire waiting to happen. The plug says - "phew, its hard work getting a fire going around here, with all this fuel and soot around" and eventually gives up the ghost due to carbonisation and quenching in his wet, black bathing pool. Mr Cam Man observes the misfiring engine and spends literally months chasing a non-existent ignition fault, before - in total frustration - strips the top end only to find a bujjered cam. Now, for Mr Cam Man, all un-diagnosable ignition faults are due to worn cams! Well, its gorra be a possibility innit? Discuss!

As your other seven sparks are all OK (you may already have genuine components) and after cleaning the No 1 plug, things improved somewhat, then replacing all plugs and leads plus dizzy components seems extravagent before further evaluation. You could view this as "not" an ignition issue whereby the sooty plug has been caused by a weeping injector creating an over rich No1 mixture, misfire and eventual quenching of the spark (as seen on the strobe) by the developing bad plug condition. Its possible because the strobe sensor on the plug lead requires voltage to generate a light pulse, but if the spark is somehow quenched then that voltage tracks directly to earth and will fail to energise the strobe light. To work around that possibility try this sneaky ignition test. Take off the No1 plug lead, run the engine on 7 cylinders, pro-tem, and observe the ACTUAL No 1 spark with a spare plug lodged on the engine. If the fitted plug is actually OK and there is a fault in the ignition system, as you saw on the strobe, you should also see it failing at the replacement plug. When the fault is eventually fixed, go back to the person who gave you cam advice and tell him it was due to a faulty brake light switch.

Hello Rob, I pulled this from my essay on exhaust systems as per the RV8 in SD1's. Heat! Exhaust gas is hot, and it would be good to keep it hot throughout the exhaust system. Hot gas is less dense than cold gas, so the colder the gas the heavier it gets and therefore takes more effort to remove it from the system. Larger pipes give the hot gas an opportunity to slow down and give the gas more time to cool en-route to the tailpipe. We don't want our engine to be pushing a heavy mass of exhaust gas out of the tailpipe and it is not just that an extremely large exhaust pipe will cause a slow exhaust flow, which will in turn give the gas plenty of time to cool off en route. Overlarge piping will also allow our exhaust pulses to achieve a higher level of entropy (Sorry! Entropy is the way energy spreads out in a process), which will take all of the hard gained header tuning and throw it out the window, as pulses will not have the same tendency to line up as they would in a smaller pipe. If keeping the interior of the exhaust system as hot as possible is an advantage, then coating the entire exhaust system with thermal insulation material, such as header wrap or a ceramic thermal barrier reduces the cooling effect significantly. Cost may be prohibitive but a bonus side effect would be a cooler engine bay and down-pipe area Lots more about pipes, heat, noise and materials in the PDF available from here: http://www.vintagemodelairplane.com/pages/.../Exhaust01.html

Thats it, right there. Nothing else matters until you fix the mixture problems, changing plugs will make no diff to the root cause. Generaly, Five component issues will cause the overfueling. # Coolant temp sensor or associated wiring faulty, check characteristics with ohm meter and continuity tests # ECU check by substitution. # Throttle position sensor. measure for electrical noise when rotating # Pressure reg, vacuum control tube not bringing pressure down when needed. # weeping injectors - perform a pressure leak down test., Less likely - the AFM is faulty - check by substitution.