Its broken

[LongBaz383BHP]

Was out for an early morning hoon this morning and it just died. Managed to pull over and no fuel pump. AA arrived . Swapped over the relays and still no fuel pump but would turn over. AA man shorted both the relays and it started. Took the wires off and it kept running. Drove it 100 yards and it stopped, no fuel pump. Back on the low loader and got home.
Put the Rover Gauge on and cant get a connection from the ECU to see any fault codes?
Put the accumate on and wont go to green....anything to do with it?
Ordered two new correct relays as I have read one wont work without the other.
Any thoughts or suggestions chaps.
Thanks
Barrie

[Aussie John]

One relay supplies power to the ecu, if this is jiggered then you won't get any info..

[Harrytsg]

Just a thought on the rover guage connection, I have an Ecumate, and it only powers when I turn the ign on and reset the alarm.
This caught me out once, the car was unlocked and roof off, just mucking about generally, connected the Ecumate and turned ign on but it wouldn't connect, pressed the alarm (this is the abridged version as I spent about 5 mins wondering why it wouldn't work) and it powered up.

[MPoxon]

Mine cut out similar to yours last year. No priming of the fuel pump and no connection to the ecu when connecting the ECUMate.

Turned out to be a bad earth to the ECU. Write up here:

http://www.pistonheads.com/gassing/topic.asp?h=0&a...

[LongBaz383BHP]

Thanks for the replies so far. Suppose I will have to see what effect the two new relays have.

[LongBaz383BHP]

Well put in two new relays and pump still not working. Turns over as before. Any thoughts on what to look at next.??????
Barrie

[gavgavgav]

One easy check is to see if there is 12v at the pump, if so try re-earthing the pump. That was the trick for me.

[K4TRV]

gavgavgav said:

One easy check is to see if there is 12v at the pump, if so try re-earthing the pump. That was the trick for me.

As above and possibly your immobiliser?

I had the relay go as per this: : http://www.pistonheads.com/gassing/topic.asp?h=0&a...

HTHs?

Trev

[pb450]

Original Meta alarm still? If so I bet this is the problem.

They all go flakey at this age. (My '98 450 did.) Repairs are possible but problems WILL reoccur - eventually.

Fix it once and for good. Carl Baker is your man. Regular appearances at Taylor TVR. He's doing 12 new alarms there in the near future! Not cheap but not expensive either when it's fixed for good.

[db484bhpv8]

Barrie have you checked ALL your fuses? Also might be worth running a new and beefier feed to the pump. The original wiring isn't up to the job anyway.

[EGB]

Check connections to fuel pump are clean and bright and getting 12V and good earth. It's in a road dirty area. It was my B.....META. Had it bridged no more probs.

[LongBaz383BHP]

So tried the borrowed ECU still no go. Will have a look at all the fuses again tomorrow. The AA man bridged ghe relay and it worked fine but stopped after 100 yards after de-bridging. So a permenant bridging may be the solution. How is the done.

[K4TRV]

Replace the Fuel pump relay with a Bosch 0332014112 - they have a diode, internally, on the input of the 85/86 terminals.

Temporarily use a "normal" five-pin relay to confirm, but even when you switch-off the ignition, the relay will draw nearly half an amp and your battery will be flattened - does not happen with the Bosch relay with a diode internally fitted.

T

Edited by K4TRV on Friday 27th September 18:27

[LongBaz383BHP]

Hi Trevor, have replaced with the correct numbered relay but still no joy.

[SILICONEKID343HP]

Put a constant supply to the fuel pump ,see if it starts .. I got 9volts at the pump so did a neat little mod . check the voltage.

[LongBaz383BHP]

Thanks for the suggestion so far. As I've said the fuel pump works, the AA man bridged the relay and the pump worked. So thinking about it, it can't be a fuse? Is the relay the end of the line so to speak?
Quite happy with bolt on stuff but electrickery is a little begond me.

[Harrytsg]

Electrically, in between the immobiliser and the fuel pump is the inertia switch. But it can't be this as it latches when 'tripped'.
Personally I use a multi meter to establish how far along the circuit your getting the 12v, it's probably the immobiliser but could also be earths( or the lack of), fuel pump failing, lost voltage etc......

[K4TRV]

Harrytsg said:

Electrically, in between the immobiliser and the fuel pump is the inertia switch. But it can't be this as it latches when 'tripped'.
Personally I use a multi meter to establish how far along the circuit your getting the 12v, it's probably the immobiliser but could also be earths( or the lack of), fuel pump failing, lost voltage etc......

+1 ^^ immobiliser, but double check with multimeter on voltage at pump.

T

[Steve_D]

LongBaz383BHP said:

......Is the relay the end of the line so to speak?....

A relay uses a small elecrical current to switch a heavy current. It is used so that small switches etc do not get burnt out by a heavy current circuit.

Your AA man proved there is heavy current at the relay and bridging the relay proved the pum was OK.
If you remove the relay you should be able to test for 12V at variuos pins in the relay mounting base.

With ignition on and the immobiliser deactivated you should have +12V on pins 30 and either 85 or 86.
Pin 30 should already be proved (AA man).
If you don't have the other 12V then I suspect the immobiliser. If you do then I suspect a poor or missing earth on pin 85 or 86.

The confusion with 85 & 86 is that most relays can be wired either way round and it is almost impossible to find a convention. Most favour 85 as the earth.

Steve

[Aussie John]

Maybe worth checking the switch behind the glovebox.