40 replies to this topic

[Mini Stripey]

Sprocket
You've found it!
Started car this morning ran perfect until warm, plugged spare stepper motor in and it doesn't turn, it rocks backwards and forward sort of vibrates but cog doesn't turn, tried the existing one and same, doesn't turn the cam, just sort of buzzes... thank god I think you've found the problem... but what now?
Why is it just buzzing and not turning.... feeling motivated again...
Please could you shed some light on this
Mike

[Mini Stripey]

Sprocket
New update
Swapped ecu for a spare I have but have no key fobs for it and now when I push the main relay stepper pump works perfect so would I be right saying I have a faulty ecu?

[FlyingScot]

Sounds like a faulty driver circuit within the ECU all other things being equal.
You could get it repaired or swap for matched ECU and 5AS.

FS

[Sprocket]

I wouldnt rule out wiring issues.

What about the fuel pump relay problem?

[Mini Stripey]

Fuel pump relay works fine at the moment. I was assuming that because the stepper motor wasn't working it was sending wrong message to ecu and cutting out.. I've just fitted the none immobiliser ecu and alarm box and it fired up and stopped, fuel relay again not pulling in, is it possible to just swap ecu and alarm box with none immobiliser version?

[Mini Stripey]

Fuel pump relay works fine at the moment. I was assuming that because the stepper motor wasn't working it was sending wrong message to ecu and cutting out.. I've just fitted the none immobiliser ecu and alarm box and it fired up and stopped, fuel relay again not pulling in, is it possible to just swap ecu and alarm box with none immobiliser version?

The none immobiliser ecu and alarm box didn't come with any fobs, do I need fobs to use the different ecu and alarm box. It cranks over but fuel relay doesn't activate
HELP

[Sprocket]

What follows is for mid 1995 onwards cars with the 5AS alarm with standard in altered wiring.

You can leave the alarm ECU that came with the car in the car and fit the non immobilised engine ECU. The alarm and the starter inhibit immobiliser will still function as normal.

Im not sure what non immobilised ECU you have as they dont have a separate alarm box as such so wont come with any fobs. They do have a dummy box that looks similar to the alarm box, or, I have seen imobilised ECUs be altered so that the immobilised function no longer has any effect. It all depends what parts you have.

Incidentally, the alarm ECU and engine ECU are matched pairs. If the immobilised engine ECU does not receive the correct code from the alarm ECU, the engine ECU functions are inhibited.

To be honest, this is really the wrong topic to be discussing this in. It would be better if you can start a fresh topic and start from there.

[Mini Stripey]

My mistake the ecu and alark box do have immobiliser, it just didn't activate for a while, at least I know wiring is ok and stepper motor is ok, I'm assuming I have a faulty ecu..secondhand ecu fob and alarm box on its way, fingers crossed this is the problem. I don't know where else to look

[Mini Stripey]

I wouldnt rule out wiring issues.
What about the fuel pump relay problem?

I wouldnt rule out wiring issues.
What about the fuel pump relay problem?

New ecu fob and alarm box fitted now stepper motor functions correctly.. but oh no, fuel pump relay still not pulling in.... I'm totally at a loss.....anybody please help
If I hold relay in starts and runs perfect
Anybody out there?

[Mini Stripey]

If the ECU is not grounding the fuel pump relay coil, first check the crankshaft sensor.
 
Does the fuel pump run for a second or two when the ignition is turned to position II (IGN)? If yes then the ECU is OK, and it's likely a crankshaft sensor problem.
 
One other thing to check, does the main relay also pull in when ignition is turned to Position II (IGN)?
 
Stepper motor will motor the throttle full closed and back open again when ignition key off. If it doesn't there is a more fundamental problem than just the fuel pump relay.

Fuel pump relay not kicking in at all ??? Please anybody can help

[Mini Stripey]

If the ECU is not grounding the fuel pump relay coil, first check the crankshaft sensor.
 
Does the fuel pump run for a second or two when the ignition is turned to position II (IGN)? If yes then the ECU is OK, and it's likely a crankshaft sensor problem.
 
One other thing to check, does the main relay also pull in when ignition is turned to Position II (IGN)?
 
Stepper motor will motor the throttle full closed and back open again when ignition key off. If it doesn't there is a more fundamental problem than just the fuel pump relay.

Fuel pump relay not kicking in at all ??? Please anybody can help

Main relay pulling in perfect

[Mini Stripey]

If the ECU is not grounding the fuel pump relay coil, first check the crankshaft sensor.
 
Does the fuel pump run for a second or two when the ignition is turned to position II (IGN)? If yes then the ECU is OK, and it's likely a crankshaft sensor problem.
 
One other thing to check, does the main relay also pull in when ignition is turned to Position II (IGN)?
 
Stepper motor will motor the throttle full closed and back open again when ignition key off. If it doesn't there is a more fundamental problem than just the fuel pump relay.

Fuel pump relay not kicking in at all ??? Please anybody can help

New crankshaft sender fitted. 99 times out of 100 fuel relay not kicking in on position 2 or crank

[P5151]

Similar problem on mine, on checking the resistance of the relays the starter relay is 70.1 ohms. I would have expected an open circuit to stop it working, will a raised distance stop it too?

[Mossi22]

WOW, can't believe it.

mine is doing identically the same, if its any help I've gone down the same route.

mines a ground up restoration, so everything is brand fire new apart from ecu, immobilizer and spi unit.

will be having another crack at it tomorrow.

I'll let you know if i find anything.  

[Alexxx]

old thread but I need some help in this area.

Car is a 1998 mpi bought (off my brother) it  was a car that started but been off the road for yrs.

I cannot get the fuel pump to work, car cranks and fires on easy start but no fuel getting through.

Found the fuse relay box attached to the top of the servo, nothing burnt, no dry joints.

Connections all clean, put it back and powered up the ign, I could see the main relay had switched on but the fuel pump relay did not close, I closed it manually, nothing, no pump activation (I referred to SPI relay pack functionality on this site )

The connections to the ecu are all good and clean, that looks like it is rubber insulated and the case does not earth.

I checked and cleaned the pins on the three relays top LH engine bay, checked the 15 amp fuse there too, all good.

All the fuses inside the car are good.

What do I need to check next?

Edited by Alexxx, 24 April 2021 - 11:56 PM.