Electric Gremlins

[Guest danny_samb]

Hi all the electric gremlins have been over the winter. Went to start the car this morning and no power to the fuel pump. Checked all fuses and they fine. Car turns over and everything else seems fine. Cars a superspec, anybody got a wiring diagram so I can see what relay or wiring I need to check.

Thanks

[alanrichey]

When you turn on the ignition the ECU should trigger the fuel pump for 2 seconds. I assume that isn't happening ?

 

If not then you either have a fuel pump/relay issue or an ECU/relay issue.. To try and eliminate 3 out of the 4, when you turn the ignition off you should get a short 'chatter' as the idle positioner resets, then listen very carefully and a few seconds later you should hear a click as the ECU relay resets. If you aren't getting that then it might be the power supply to the ECU relay. (Or if you know which is the ECU relay then hold it to feel the operation)

 

If you do get that click then it is the fuel pump/relay. Have you identified which relay is the Fuel Pump ? If so then hold it while you turn on the ignition and see if you can feel it click. If it does then it is probably the fuel pump area so check to see if you are getting power to it for 2 seconds when the ignition goes on.

 

Come back with results

[AndyW]

Hi Danny,

Is yours a Superspec with the Rover 2.0 engine? If so the fuel pump is in the tank and powered by a relay. The Rover MEMS uses 3 relays for the main ECU, fuel pump, and O2 sensor heater. Each of the relays should be fed from the battery through their own fuses. On mine there's a green wire goes from the relay to the fuel pump along the central tunnel.

 

The fuel pump relay is controlled by earth trigger from the ECU. When you turn the ignition on you should be able to hear the pump turn on for a few secs to pressurise the system then it turns off until the engine is cranked.So you won't hear the fuel pump running much.

 

There may also be a fuel cutoff inertia switch fitted, normally somewhere between the relay and the pump. If you have one see if this has been triggered and reset it.

 

Unfortunately there isn't a useful wiring diagram for the Superspec. I'm slowly drawing one for myself but not complete yet.

 

Some things to check.

Cheers, Andy

[AndyW]

Al beat me to it with more info :-)

[Guest danny_samb]

The fuel pump is external, no fuel pump prime when turn the ignition on, get chatter, had the multi meter on the wiring fuel pump end and getting no reading, all worked fine when last used it

[alanrichey]

Good call from Andy on the crash switch, I had forgotten that. Awaiting your findings on the 2 relays.

[Guest danny_samb]

Not sure how you test a relay. I'm pretty sure it's the relay for the fuel pump that's not working. As here the ticking and the click when ignition turned on from the ecu. But the fuel pump is doing nothing. A big 0 on the mutlI meter. I'll have a look at the cut off switch but it's jus been sat on the drive. Did find a blown fuse so replaced that and it's not blown again. I'm pretty sure the fuel pump came on the 1st time tried ignition, so I'm wondering if the relay was stuck so blew the fuse and now nothing

[alanrichey]

Thinking further, if you are getting the ignition off 'chatter' then the ECU relay must be working and powering up the ECU. And you have proven that no power is getting to the pump. So that narrows down the problem to the fuel relay, the fuse, and the crash switch. The crash switch comes after the relay so if you check the terminals on that you will know if the relay is not switching.

 

(Overlapped with your post). Check the voltages on the crash switch still valid though. And I always have a spare relay to swap over.

Edited February 19, 2017 by alanrichey

[Guest danny_samb]

Have you got a link or part number for the relay I would need. Where would the crash switch be located. On a quick look there is nothing obvious

[alanrichey]

A standard 4-pin relay is all you need.

 

12V Relay 4 PIN Automotive 40AMP 40a Changeover RY15 Normally Open Contact

 

But as a quick check, swap over one of your other non-essential relays (horn, fan ?) and see if it solves the problem (and stops the horn/fan from working)

 

The kill switch may not have been fitted, depends on the original builder. Mine looks like this

 

 

The kill switch is at the bottom centre, you reactivate it by pushing on the top. Just for interest, as yours may very well look nothing like this, the 2 relays on the left are the Fuel Pump and Lambda Heater (I have no idea where the ECU relay is, it must be behind the dash somewhere) and the 3 relays at the top are Windscreen Demisters, Fog Lights and Horn. My fan relay is under the nose cone. No doubt yours is completely different

 

A lot of this is covered on my blog. If you haven't read it I would take a look. The URL is in my signature block.

Edited February 20, 2017 by alanrichey

[Guest danny_samb]

Ye mine looks completely different. The original builder used a standard fuse/relay box. There is a relay that has fuel wrote on it, so I'm guessing that's the 1 I need haha, I'll do some detective work at the weekend. I'll pull the relay and test if getting 12v to the relay. If I am then I'm guessing the relay is faulty as not getting 12v at the pump.

[alanrichey]

I still reckon it's easier to just swap it with one of the others (Although not the ECU one). If you don't have a kill switch fitted I would recommend you get one.

[Guest mcramsay]

Possibly the fuel pump has seized over the winter and popped the fuse when you put the ignition on? I've had it happen on cheaper pumps...

[alanrichey]

Just found this in my collection of Google search results. It's the wiring diagram for the engine loom for MEMS 1.6 for the Rover 400 system.. So it matches ours fairly accurately.

 

http://www.rmrsoft.com/mems.pdf

 

Cheers

 

Al

[Guest peter2b2002]

I had the same on my old 2b engine spun but no fuel I had a test meter but no 12v on the pump so as I was out side a motor spare shop I went and got a switch, fuse and wire fixed it to gether to get home, never did find why I lost the feed to the pump so just left the switch in place still there till I sold it 10 years later

peter-2b