10 replies to this topic

[Classic1275cc]

1994 Rover Monte Carlo SPI

 

Quick background - Issue of no power to fuel pump after a 3rd jump start while shuffling it around through out the day,
Can start the car by taking 12v from the battery to the fuel pump from the battery directly

 

Have lost power through a popped fuse once before while driving, the once offending fuse this time checks fine on the multi-meter  

Things i have checked, tested, bypassed.. swore at

1. Fuses above Air cleaner 

 

 Fuses Behind Airbox.jpg   29.43K   12 downloads

 

2. Crash stop cut off 

pressed and by passed 

 

 Crash Stop.jpg   26.08K   14 downloads

 

3. Main fuse box 

 

 Main Fuse Board.jpg   14.98K   6 downloads

 

4. used another relay box, although can not confirm that this also may contain a dud fuel pump relay

 

 Change of CDI.jpg   28.32K   9 downloads

 

5. Fuses that sit left and under air box 

 

 Left of Air box Under It.jpg   28.33K   13 downloads

 

6. Fuses under steering column

 

 Under Stearing Collum.jpg   17.98K   21 downloads

 

So completely lost other than the only thing left but i cant check is the fuel pump relay in both my main relay boxes being duds, but find it a bit suspicious giving it has popped a fuel pump fuse of its own accord previously a year ago, and its died this time while i was jump starting it hmmmm. but like i said that fuse (the blade fuse in point 1. which previously popped a while ago and killed power to the fuel pump checks out and also bypassed the fuse carrier (which is a grey/brown wire) 

 

7. Wiring Diagram 

 

 Wiring Diagram.JPG   90.76K   36 downloads

 

Any advice would be great feel like i have checked all i can / know about 

 

[mpialan]

Have you checked the continuity of the wires between the plug for the inertia fuel cut-off switch and the pump end?

[minimat]

I have known  people to trap the wires to the fuel pump when removing and refitting the tank, can you hear the fuel pump relay click, sometimes you can open the box up and see if it moves and if not move it across by hand. If yours has the two button fob the alarm cuts the fuel pump power , the earlier single button ones like mine (also a 94 spi) only cuts the starter motor.

Check all the inline fuses very carefully , they are c**p and cause all sorts of problems, best thing i ever did was replace them with blade fuses.

[genpop]

When you take current directly from the battery, put a fuse in between.If this blows out too then it is the fuelpump.

[Bat]

Hi,

Check for ignition power at fuse LF7. I think it will be fine, but check to be sure.

 

Then on the black relay box plug put your red probe into one of the thick brown wires and check it's live all the time.

Then leave the red probe where it is and put your black probe into the black and purple wire.

You should now get battery voltage on your meter when cranking the engine.

 

If not check the black purple wire again where it comes out of the ECU.

If nothing here you need to replace or repair the ecu.

I think Sprocket has seen this on another SPI recently...

Cheers 

[pete l]

Should be quite easy to fault find.

Check to see if the pump is getting power, if not, check the relay output, if output ok at relay and not at pump, there is a wiring fault.

Check the coil of the relay is getting power, if not, check the cable from the ECU to relay, check the ECU is giving power to it's output pin.

I think a crank sensor fault can stop the ECU from powering up the relay. 

[viz139]

I would start by checking for 12volts at the inertia (crash stop) switch. 

If there is power there than the problem is in the wiring from there to the back of the car. proberbly the connector between front and rear looms.

If there is no power here than its fuse or relay box.

Are you sure the second relay box is SPi and not MPi.Same connectors but not the same inside.

[Classic1275cc]

Thank you all for taking the time to reply to this, very clear tips and I will try these out Tuesday evening after a shorter day at work

Edited by Classic1275cc, 24 September 2018 - 06:24 PM.

[hunterg30]

Unplug the main ecu and check contacts are clean .make sure the plug is fully pushed in.

[Sprocket]

The one I'm looking at we have narrowed down to an ECU fault on the fuel pump relay output. We are just waiting to effect a repair, as we are both busy with more important things at the moment.

 

If the 10 amp fuse has blown, you're probably looking at a fuel pump fault.

 

If you ground the Black/Purple wire somehow (at your own risk) on the small connector on the relay pack, the fuel pump relay will energise when you turn the ignition on. if it doesn't, you have a fault on the wiring, connectors, fuse, inertia switch, or the pump its self.

 

If the fuel pump does run, and the engine starts, runs and the car drives normally, they you're likely looking at an ECU fault, to which I've had first hand experience, and also word from a fellow club member of his experience of the same fault.

 

Don't leave the black/white wire grounded though, as funny things can occur with back feeds an such.

[Classic1275cc]

Solved 

unfortunately i'm not sure 100% what i did, but here i was i did before it worked again 

unplugged the relay pack and checked for constant 12v on the two browns 

checked for continuity from the pump switch through to the fuel pump connection 

put my needle plyers into the fuel pump connector and crimped down the spade a bit for a better contact

charged the battery 

 

... somthing worked anyway!