TRAVELLING ESPRIT MAN (MON) - HELP!!

[Erikl]

The Fuel Pump and ignition relay are identical and next to each other IIRC.  Positive you are on the right relay?

One thing you might try, there is a similar relay on the other side of the box, plug it in.  Its wrong and makes the fuel pump run all the time (I learned this hard way - face palm).  

The computer is common to a bunch of GM vehicles for that era and cheap, you just have to change the chip out is my understanding (have not done this).  

Also Esprit Engineering there in the UK fixes them IIRC - check their web site.

[Escape]

Don't lose faith, you've actually proven it is NOT the ECU. If it was, jumping the relay would make the pump run, as the ECU has nothing to do with it. Now you need to check why there is no 12V feed to the relay (pin 30). You've already checked the fuse, but was that for continuity or did you actually measure 12V on both sided of the fuse? If the 12V side checks out, only the earth connection to the pump remains as a possible cause.

You're very close, it's just a basic electrical problem, probably a bad connection somewhere.

Filip

[Rambo]

I would agree too. It does sound like a simple electrical problem.

Did you check out the relay connector?

[madmax]

Thanks guys - I'm heartened by your replies, particularly the one suggesting the ECU could be ok.

One additional thing that I may have mentioned earlier is that I got a friend to turn on the ignition switch whilst i held my hand over the relay where I was able to feel a definite click - suggests to me that the relay could be working too.

What I haven't checked is feeding power to the pup from the pigtail in the engine bay directly on top of the tank. Whilst I fed the pump with power and it worked, I sent it directly to the pins on the top of the pump rather than through the wires that lead to the pump. There could feasibly be a break in one of the feed wires that run in the tank, surrounded by fuel which might give the symptoms I'm experiencing perhaps?

If it would stop raining for an hour (fat chance) I could dismantle it all again and check this out - ever hopeful for a simple fix 😉

[fjmuurling]

"The way of power" to the Fuel Pump is (on my 1990 SE):

1. Battery
2. Fuel Pump Fuse
3. Fuel Pump Relay which is controlled by the ECU
4. Inertia Switch
5. Fuel Pump

Checking for Power after each component (+12V) in the above sequence make things easier to track down for the possible power problem.

Bridging / Jumping the contacts 30 and 87A on the Fuel Pump relay only takes out the relay of the "chain". Further down the line there is still the inertia switch. If this one is faulty than the pump will also never run.

I'm speaking from experience where the car/engine stopped (close to home) due to no more running of the fuelpump. In the end as an emergency repair bridging the inertia switch solved the problem and I was able to drive home. The inertia switch was not "activated" etc. I replaced it later on and all was OK again. 

[madmax]

Thanks for this @fjmuurling - before I start to dismantle everything again perhaps I should try to jump this switch as what you experienced sounds just like my circumstances

[sailorbob]

Does the car have an aftermarket alarm and/or immobiliser?

[madmax]

I did think of that but it seems to work as it's always done. It's a Sigma system that when its set to open the car, I have about 15 seconds to turn on the ignition and fire the car up. As things stand it behaves exactly like it's always done, unlocks the car, gives me my fifteen seconds and allows me to crank the starter. If I miss that 15 second window the car is entirely dead, no dash lights whatsoever. So unless it's being very particular, it seems to be operating as it's always done although I appreciate it's another level of checking perhaps - still raining...................

 

[madmax]

I'm afraid I've given up chaps - tried everything I can think of and everything I think other people have thought of now and till exactly the same - engine turns merrily but won't run and there's no sound from the fuel pump. The other evening I removed the fuel pump from the tank - again and instead of powering it directly to the pump terminals I sent power from the top wires, the ones normally submerged in petrol and the pump ran. I then put power to the pigtail sticking out from the top of the pump frame, the ting that's held in by an awkward to refit locking ring, and again the pump spun up fine.

Later I jumped a wire across the two contacts leading to the inertia switch to take that out of the equation but exactly the same happened.

So, to summarise, the battery is good, the fuse is intact, the fuel pump relay clicks when ignition is switched on, and the inertia switch appears intact and I have a wiring system that appears intact all the way to the pump.

What the F else could be wrong and what haven't I tried yet??

[Erikl]

Consider jumping the relay, if pump runs start the car.  curious if any other codes.

[fjmuurling]

If the Fuel Pump relay clicks is does not mean that the switch contacts in the relay are OK.

1. Make sure that the connectors in the relay holder are in the right position (ie Not moved down). are clean and that the connection to the wires are still good.
2. Replace the relay for a new one (they won't break the bank).
3. Check voltages after every single item.
4. Check / follow wires and find out where / if the alarm (immobiliser) system might interfer with the fuelpump power system. (most likely you will find the addional wiring (if fitted) somewhere in the "spaghetti mess" above the right hand fuel tank)

As a side note the ECU will run the Fuel Pump for aprox 5 seconds and than stops it after switching on the ignition and not starting. Of course if you start the car the fuelpump is commanded on again.

[madmax]

Thanks for this but at the roadside the first few things I did was to check the inertia switch, check the fuses and swap some relays over and nothing has changed since. 
Being a novice with electrical stuff doesn’t help of course but I did buy a small multimeter with a +ive and a -ive probe to try and feel at least armed with some proper kit. 
I have a Power Probe too that can send 12v but don’t really know what I’m doing. 
I know that the pump actually works and jumping various bits in the run to the pump have made no difference. 
I guess I’ll just have to join a queue for a specialist and hope it’s not something out of reach financially.
It was running so well too and took me to Croft for a 75 year gathering without missing a beat.
Still love it - just want it back 🙂 

[Escape]

I do hope you stick in there, as you really can't be far. The above suggestion of jumpering the relay (if I read correctly that makes the pump run?) and then trying to start is definitely worth a shot. 

If you do decide to call in help, you're not limited to a Lotus specialist. Everything points to an electrical problem, so if you know or can find a reliable auto electrician, he doesn't need to be familiar with Lotus to find and fix the issue. All he needs is this wiring diagram:

We should have asked if you had the diagrams at the start of this thread, and provided them if you didn't, sorry... It really shows everything you need to know.

Filip

[Chillidoggy]

Just to be clear, when you run 12v directly to the fuel pump plug, the car will start?

[Rambo]

I agree with Filip, you can't be fat away. Something simple has been overlooked.

PS a similar thing happened to me at Silverstone (M100 though, but similar problem) With the help of 2 knowledgeable (M100) friends we bypassed the fuel pump relay as we couldn't hear it prime. We put a live feed to the fuel pump and lo and  behold it started and got me home the 300 miles. Further diagnosis by me at home, with the aid of the electrical diagrams and a "bit by bit" approach led me to a poorly seated fuel pump relay

[madmax]

20 minutes ago, Chillidoggy said:

Just to be clear, when you run 12v directly to the fuel pump plug, the car will start?

I've only ever connected the pump to 12v when it's been out of the car - since the breakdown two weeks ago the car hasn't started at all (apart from firing for moments at stall giving symptoms of no fuel - like you get when you're using up what's in a float chamber). Once I'd tried several times at the roadside, that was it - once the pipes were dry there's been nothing since.

Because it was roadside in rush hour I couldn't hear that the pump wasn't spinning like I normally can but once the traffic had cleared I couldn't hear anything which led me to suspect the pump.

Thanks for your continued encouragement and the wiring diagrams 👍

[Rambo]

I'm no electical expert but have you checked, or tried bypassing, the immobiliser?

Also, try taking a direct feed from the battery to the fuel pump with it in situ. Does the pump kick in?

It can only be something on the circuit diagram which is causing your problem.

[Steve V8]

Don't give up yet Simon, I've just read back through, it's not clear if you have established weather or not the ECU is talking to the fuel pump.

Remove the filler cap on the RHS and listen while someone else turns the ignition on, you should hear the pump prime for 2-3 seconds if it's working. (That's every time the ignition is switched on regardless).

One other thing mentioned in the service notes, if the throttle position sensor is stuck in a fully open position whilst cranking the engine the injectors are shut down.

 

 

[Chillidoggy]

Still waiting to see if the engine runs with a 12v feed direct to the pump.

[madmax]

3 hours ago, Chillidoggy said:

Still waiting to see if the engine runs with a 12v feed direct to the pump.

Not sure how to do that other than literally running fresh cables from the battery direct to the pump. Missing all the other gubbins - but then it would just run and run

I really am an embarrassed novice when it comes to electrics 

[Chillidoggy]

Process of elimination, if the engine runs when a 12V feed is connected to it, you know the pump is good. But then the pump is not getting voltage as it should, and you can trace it backwards from there, step by step, using the wiring diagram Filip posted earlier. If you’re unsure of electrickery, then it’s better to find someone to assist you who is before you make a cock-up.

[Escape]

22 hours ago, madmax said:

Not sure how to do that other than literally running fresh cables from the battery direct to the pump. Missing all the other gubbins - but then it would just run and run

I really am an embarrassed novice when it comes to electrics 

Do you have 12V at the fuel pump relay (on the P wire from fuse B3)? If so, putting a jumper in the relay should make the pump run as well as power the injectors and should allow the engine to run (bar other problems). You can always shut it off, as cutting the ignition will stop the plugs firing.
If the pump doesn't run with the jumper, there's the inertia switch and immobiliser to look at. I would just take out the immobiliser, both on the feed and earth side, just to be sure it can't cause problems either now or somewhere in the future. Running new wires directly to the pump, just for testing, will work as well of course. The main thing is to locate the problem. Implementing a good fix is the second step.

Filip

[madmax]

I'll have to check the relays and everything again as using details from a recent post about the diagnostic readings without Freescan or similar, I'm heartened (and baffled) that I don't appear to have any fault codes stored.

The CDL lights up, then consistently flashes 1, then 2 and repeats ad infinitum. From what I've read that means it's a sign it's in diagnostic mode but isn't registering any faults. The fans run and the water level light come on when I bridge the ALDL connector but apart from that, everything seems to point to no faults found.

As mentioned by someone earlier, I'll check if I can find an earth strap for the tank as it could be something as simple as that if the pump ain't running. I thought I'd checked that but maybe not done it right.

Thanks again for all your help and encouragement guys - feel closer to a solution now I know it's not bringing up any codes so it may be something more fundamental. Can anyone tell me the precise location of the tank earth please?

[Erikl]

Have you downloaded your copy of the Service Manual and the Parts Manual from this forum?

They are invaluable in learning about the cars.

The grund locations are shown in there, if I had a minute I would pull it up.

[madmax]

I do have a hard copy now of the service notes although one particular section (you've guessed it)is't included.

I have seen some on line information though so I have it to work though - thanks