Toby S

Success 12.6v at fuel pump and fuel pumps primes and runs Did the trick of running a fly wire from Battery to the live attaching at the pump (thanks for the tip Andrew) and working back through to the MFRU - found 2 things dodgy connection at fuse box sorted that and then did the join of the 8/4, 8/6 at MRFU as suggested above and fuel pump primed - checked voltage at fuel pump 12.6V - however found a kink in wire feeding the small MFRU connection at Pin1 giving intermittent problem - straightened, cleaned up connection at ECU end and MFRU and problem stopped (well tried it 10-15 times and fuel pump primed each time) - Fingers crossed for tomorrow although at least now if there a problem I know where to look.Thanks for the help and advise guys P.S. Before I started I changed the battery in my multimeter (was probably a couple of years old, but decided from the start I wouldn't take any chances)

I've got R888R, albeit on 13" wheels and probably higher profile - running 185/60 on front 205/60 on rears - and I've found the grip excellent for road use in dry and wet/damp conditions - not been out in heavy rain (with brooklands you tend to hide under the nearest tree anyway in rain)

If its unsightly tarnished primaries coming out of the side, Harpic loo cleaner and elbow grease brings them up nicely

P.S Andrew Re voltages - I shared the following with Jonathan over a PM yesterday Nothing on - 12.95v Ignition on 12.95v On crankng engine - initial drops to just under 10v for a moment and sits at 10.3 - 10.4 during continued cranking Fuel pump doesn't prime before cranking Back to 12.95 after cranking (ignition on only as not started) We agreed that this is unlikely to be the main problem but will clean up all battery connections whilst I'm at it and recheck

Hi Andrew Many thanks for you reply. I think the one of the problems I seem to have is the wiring colours don't seem to match anywhere once you're past the fuel pump Fuel pump - yellow/green and black - tick Interia switch - brown/grey and white and purple - hmmm Fuse box - both purple and white - hmmmSeems I have a car wired by a colour blind electrician !! Re what I thought of as the main loom plug, on mine this sits on the main bulkhead/shelve (same bulkhead the ECU,and MRFUsit on) directly on top of the heater blanking plate under the the heater bypass hoses (I guess when the car had a heater it may have been dropped into engine bay). I may have got confused by the sight of white and purple wires in there (interestingly no green/yellow) and in the 1992 handbook wiring diagram it describes the wire going to fuel pump as purple/white Re the plug you refer to at front on drivers side, there is no large grey plug but there is however a smaller black plug (circa 6 pins) which sits along side a thick sheaf of wires (I assume the engine loom) and a much smaller sheaf of wires. Now interestingly the smaller sheaf comes out of the sheaf which goes on to the black plug, by passes the plug and then returns back into the sheaf coming out of the other side of the black plug - I wonder if at sometime in its history the original plug was part replaced and the by pass put in on some of the wires (I can definitely feel a join connection under this smaller sheaf of wires). Certainly seems worth investigating The only other plug around there seems to be under the throttle body and all wires from that seem to be linking to the throttle body itself (I guess the stepper motor/throttle bodies) and I can't see that being linked Excellent tip on connecting a fly wire at different points on the system by the way and seeing where I can pick up the other end, and certainly should help locate wires in the circuit. I think disconnecting the MRFU big plug (and the main leads off the battery as well I guess) and connecting the fly wire from battery to the pump and then going hunting will be the trick disconnecting at various points - definitely want to see what is under that smaller sheaf of wires referred to above - wouldn't surprise me if I find a colour change of wires !!. Probably will be this weekend's work if dry, but I'll keep everyone posted - You never know Andrew, you might find yourself with a completely alternative wiring diagram for the fuel pump circuit !! Thanks again for all you help guys

Thanks EEK Seems like the Ecnoseal plug on yours (mine has scorching too) - may try an locate a new plug (Redline maybe) and do a complete new refit of all connectors and clean up of all the wiring round it I've also PM'd Karl H whose thread you kindly attached to see what in end his loss of voltage was down to - hopefully he's sorted his by now. I'm also charging up the battery after checking acid levels (Jonathan advised the the voltage on cranking was low, although that wouldn't explain the pump not priming on ignition switch on) Still welcome any other ideas from others too in my quest to find a solution. Next weekend's work Bloody electrics !!!

P,s, - I tried bypassing the inertia switch as well and it didn't change any of the readings at fuse box or pump

Hi Guys I'm having same sort of problem as detailed above on a 1992 ECU2 1400 Supersport – and found this on archive (through google search in the end). Seem only to be getting around 8v's if anything at all to the fuel pump on volt meter (seems to vary sometimes nothing or under 1 volt and sometimes up to 8v, although slowly climbs to this if at all) and pump will not prime – same on cranking the engine post priming phase. Have tried fly wires (both live and earth) straight from battery and pump works fine (should do a new pump) - Reconnected the normal earth wire and leaving live fly wire and again works fine, so would appear to be the live side of circuit. Battery is circa 12.85v before cranking and on normal ignition switch on On cranking drops to 8-9 volts At FIA key:- 12.85V both sides so no drop there MRFU - Input pins Pin 2 12.65V, Pin 1 – 0 at Pin 2 which I think is correct MRFU - Output pins Pin 4 and pin 12.6V Tried both a new MRFU unit (YWB 001022) and a spare and same results with both At fuel inertia switch seems to be 12.4V on the brown and blue wire entering the inertia switch – Other wire is a white and purple, which seems to lead off into the loom. At fuse box between nothing and 8v, with the volts slowly climbing during the usual priming stage and also on cranking the engine post priming stage The problem I’m having is the “Grey” ecnoseal plug per the diagram attached above (I’ve been using) - same as Reviila’s on the Technical Guides section (EU2 Non-VCC), but that doesn’t show the inertia switch https://www.lotus7.club/sites/default/files/images/docs/guides/WiringDiagrams/WiringDiagramNonVVC.png I’ve also looked at an older version by Shaun-E which includes the inertia switch https://www.lotus7.club/sites/default/files/images/Docs/Guides/YSB104490%20Engine%20harness%20K-series%20EU2%20non%20VVC.pdf Basically cobbling my thoughts together between the 2 The sequence I am working to is - MRFU to Inertia Switch to main engine loom plug to fuse box to pump The problem I have is locating the main loon plug C162 per Revilla’s diagram – where is it – I have a fairly large black plus which seems to be coming off the loon at back of the engine (circa 1 feet away from the MRFU and EMU) which I assume iss it, but this only has circa 9 connector pins and on separation looks nothing like the C162 plug detailed in the revilla’s diagram, although does not look dissimilar to the main engine loom detailed in the 1992 handbook on separation (big black location plastic bit in the middle of plug. The purple and white wire seems to be coming in/out on pin 4 on the top row of wires on this plug Unfortunately time ran out today, but assuming my understanding of the sequence in the wiring diagrams, and the 1992 wiring is not dissimilar , it would seem to me to date I’ve located the problem to be either the main loom plug itself (on separating the plug, their did seem to be quite a lot of scorching on the yellow plastic on both sides on the inside of the plug around the pin 4 so that may be it and also all the wiring looks a bit mucky both sides of the plug), or the wire from the inertia switch to the main loom plug or the wire from the main loom plug to the fuse box.Now the questions:- Is the sequence I using above the correct one Do you think I’m on the right track or is there anything else I need to consider/missed The main loom plug – given the convoluted wiring (I’m not brill on electrics and certainly some of the wire colours don’t seem to tally – may have had some rewiring in it’s life – certainly has the separate starter motor relay), I’m confused given the wiring to/from the main loom plug come in/out of the sheaved sections of loom which side of the main loom plug is coming from/going to where – the black main loom plug has male pins in the side of the smaller black outer and fits into the female pins in the larger of the black outer shells – Wires sizes to me seem smaller on the former side Which side is from the inertia switch, which side to the fuse box (may help me track which side is the problem). My main concern is that sometimes I’m getting nothing and sometimes up to 8 volts – can’t help but think there is something I’m missing if its swinging around like this. Given the comments on the main loom plug (grimy and scorching inside), do you think I should just change the plug anyway (difficult to see what state the female pins are in anyway)As ever guys, any help/advise much appreciated Many thanks in advance

I bought one last year from Redline - just the pump and the gasket

My 1992 1400 Supersport had the same problem you mentioned in #1 a few years ago and it turned out to be the switch - your switch looks pretty similar from a dashboard view. I popped the switch out and disconnected the white wire plastic holder at back - then dismantled the switch (levered the tabs at side with a flat blade screwdriver and then pulled apart) and it was crud (green oxidisation) on the metal copper strip - cleaned up and put switch back together and refitted and hey presto everything worked - 10 min job - switch is a very simple affair just a copper strip, slider and copper contact points

"We moved the fuse box" - it isn't a bad connection or something shorting the connection at the back of the fuse box like my previous post

Mines not a widetrack, but I've got Protech shocks (single adjusters) on a 1400 Supersport and I went for 250 fronts, 150 rears spring rates for mainly road use - these replaced 300 fronts and 200 rears which I found a bit hard for road use

Thumbs up for Protech from me too - Good value and I've been pleased with mine

Thumbs up for Protech from me too - very pleased with the single adjusters on my 1400 Supersport and well priced

Hi Jonathan Thanks - I must admit ECU's are a bit of a misnomer to me, but if they are monitoring fuel pressure that would make sense - not quite sure what it's going to make the engine do if the pressure is abnormal (low or high) as the the fuel pump only has an on and off position and the air intake (throttle body) is hard wired (non electrical), but I guess it must control what the fuel injectors are doing (how long they stay open for working in tandem with the crank sensor) - carburetors seem much more understandable to me !

Hi Jonathan Yep - the fuel trap box - couldn't see it stopping the fuel pump working so didn't investigate further - what does it do ?

P.S. This is on a 1992 1400 supersport - obviously the connections may be different on yours given its a few years younger

Hi Karl Thanks for the note re the relay by pass - mine has this too, although this would only affect power to the starter motor and shouldn't affect the fuel pump. I too have been having problems with fuel pump initially cutting out intermittently at first and them completely - Finally, I think, traced it to the live connection on the fuse box which directly powers the pump - self inflicted in my case - when I put the brookland screens on a year or so ago, being a lazy/smart arse (wanting the option to fit the windscreen back for winter) I merely pushed the wiper mechanism through the scuttle and held it in place with cable ties - the wiper mechanism passes behind the fuse box to the wiper motor located behind the passengers left knee trim, and during the intervening time, or so it seems, has fouled the fuel pump connections on the left hand side of the fuses box (found the fuel pump wire unconnected at back of fuse box). Probe 2 is right on location of fuel pump, although a word of caution (from experience) before you start pulling wires around the pump See above - The fat black connector is what you will see, which passes through the hole in the round plate bolted to the fuel tank (the other hole is where the fuel line screws in) - The black connector is a sealed 2 pin connector which connects to the white connector inside the tank which is wired to the fuel pump. Various problems to be wary of here (which I found to my cost) There isn't that much room to work with at the side of the tank The white connector doesn't fit through the hole in the tank - pull the black connector out (and it's very tough to do so) and you may have difficulty re-connecting to the white connector as the white connector may disappear into the tank Once the black connector is removed from the hole, there's nothing to stop fuel peeing out through the hole it came out of if you have anything more than 1/8 - 1/4 tank of fuel. (mine had 3/4 of a tank when I tried levering mine off) If you break either the white or black connector in the process, they are no longer available - I had to do a bit of "dremel and silicone" engineering to fix my black connector after my attempts.I would suggest if you want to check current getting through to the pump to determine whether the pump is knackered or not you cut the wires leading to the black connector and test and then reconnect with sealable connectors - Wish I had (may have saved me having to take the tank out to get the connection back in place and getting a gob full of fuel in my attempt to pull the connector off in the first place), albeit in the end decided to replace the pump at the same time given it was 27 years old. Other things I checked during the whole process were:- MFRU, situated under the ECU to ensure that was working OK and the relays were kicking in - you can open this with care and clean up the 4 relays inside All engine loom, MFRU, ECU connections and wires All earths - mine was by the air filter the fuel inertia switch (had problems previously with that)Hope the above helps - I'll be interested to know what you finally find the problem is - using a multi meter will certainly assist in the diagnosis. One thing I didn't check and I'd be interrested if anybody out there know what it does, it the small rectangular flatish box to the left of the inertia switch - seems to have 2 push on rubber pipes, one leading from the engine and the other to the ECU - I understand this is also something to do with the fuel system, although as none electrical didn't investigate further

Karl Relay by-pass fuse ? I've got a 92 1400 supersport and haven't come across that - where is it ?

Impressive driving to get a Cat D write off with 400 miles on the clock. Maybe he should have gone for a 160

Suppose - I guess it depends on the torque rating of the impact wrench and also if you only let rip once its very tight already and for a control length of time/blows and whether you're reusing original hub nuts etc - I realize not using a torque wrench has its pitfalls, but I'm with Roadsport as the component tolerances should be much wider when you're at that level of tightness. I know some of the snap-on wrenches kick out serious amounts of torque - 450 Ib ft plus which may give you a problem - quite useful for removal through if the nuts haven't come off for a time. Getting someone bouncing on the end of a breaker bar I can't see as any more accurate and easily mis-calculated - 14 stone bloke at 1 foot would be near ideal but where exactly are his feet and which one is he putting the weight on - Don't think I'll ask my mate Neil whose a thread stripping/ breaker bar bending 28 stone !!

I can't see them be 13" on those low profile ZZZ's - the rear wheel arches are too well filled

Hub nuts at 200 Ib/ft on a de dion Wheel nuts 55-60 Ib/ft Re hub nuts, I've always just used the impact wrench - (24v Sealy) which I think on a full charge is meant to deal up to 300Ib/ft (I guess typically its dealing out circa 250-275) . Once you get to 200Ib/ft the difference of that to 300Ib/ft is going to be minimal in terms of turns of the nut (1/16-1/8th of a turn of the nut if that) so should not impact on the bearing or thread on nut/shaft given the materials used (or so a mechanic told me) - to quote him "I've never used a torque wrench on hub nuts - when you're up there boy both are effing tight".

I guessed that to be the case - just a bit of a shock when I saw the open connections Thanks for all help and advise Revilla

Thanks Revilla Did the google search as you suggested and it seems the choice is to remove and risk knackering your injectors or leave in and risk catching fire if it fails - Hmmm Seems a likely candidate topic for a foam sump baffle mk 2 Blatchat debate. Given it was there in the first place I think I'll leave in - when I first lifted the tank plate holding the pump and saw uninsulated spade connections to the pump on both red and earth cables I was a bit shocked too - given these would have been either sat in fuel on a full tank or worse still petrol vapour on a 1/4 full tank, with the tank venting air through the a pipe off the filler nozzle, it seems to have survived 27 years without blowing up thus far