No spark, injectors not triggering...

[idontknow]

HELP!

I have a R500 that is just not playing ball.

Engine is at 8.4k miles and runs a treat (when running )

A couple of weeks ago I lost all power whilst under drive. Pulled up tried to fire her up and I seemed to have sucummed to the rover 'click', a common 7 issue. Got that sorted by cutting in a new relay to circumvent, was late in the evening so just proved she turned over and put her back in the garage.

Fast forward a few weeks, pulled her out, turns over but won't fire.

So after a bit of chin scratching I now know the following:

No Spark
Injectors aren't triggering / no power
8.8v getting to the coil (Seems low??)


I have swapped out the crank sensor, no change
I have good battery power

My gut feeling is the ECU (Stock MBE) has seen better days, before I go further down that route is there anything else I can check?

Any suggestions greatly appreciated

[petery]

What's the battery voltage at the battery? Does it drop of lots while turning the engine over?

Try charging it or using a jump pack and see if that helps.

Or does it have an immobiliser, I have know those cut in and not disarm properly if the battery is low.

Inertia switch could be another cause

[idontknow]

Battery is always on trickle charge, I think it was 12.8v when I tried it earlier, I didn't check if it dropped when I turned it over I will do that tomorrow.

No immobiliser

I did try the inertia switch too

[Megaflow]

8.8v to the coil is very low. I'd suggest trying another battery, they seem to do all sorts of odd things with EFi when they start to die.

[TheRealFingers99]

Main relay?

Does sound like classic TDC sensor failure (no spark, no fuel past the injectors), but is the fuel pump priming?

[idontknow]

Only 9.1v when cranking. Too low?

[idontknow]

Fuel pump is priming

[Megaflow]

Way too low. The ECU will have a voltage parameter where it stops calling for spark, it will almost certainly be above that.

[petery]

9v is too low needs to be high 10s as a minimum in my view

[idontknow]

So now have connected up the jump leads and pushing 14v still no spark

[Megaflow]

Hmm, odd. Is the new crank sensor a known good one?

I changed a crank sensor the other week, took 5 hours, and the new one was dodgy as well!

I'd suggest downloaded the MBE software and getting a lead to connect to the ECU and see what the rpm reading is during cranking.

[idontknow]

To be honest I tried a replacement crank sensor, there was no improvement so I put the old one back.

[bearman68]

Worth checking the inputs and earths to the ECU first to make sure the ECU has correct power supply and ground.
Check the fuel pump voltage, and check the 5v supply voltage to the cam and crank sensor. Dead ECU may well be not supplying constant voltage to the pump and sensors.
Worth having a look at the main engine / ECU relay, but that will be picked up in the above checks anyway.

Cheers

[IBDAET]

If you have disconnected the HT leads or uinjector wiring and powered up the ECU you can blow the output triacs. This will give the symptoms you describe.

You need to connect a laptop with Easimap before going any futher, or you will just intorduce more issues.

[Steve-B]

If you leave the battery charger on, disable the immoboliser, then turn the ignition to ON but not start it, do you get 10-12 VDC at the injectors?

If you do the battery is toast.

If you don't, get a copy of Easimap as already mentioned, see what your ECU is saying. Triacs fried isn't out of the question as pointed out.

[idontknow]

Can some post a complete idiots guide to hooking up thr ecu to use easimap?

[IBDAET]

Its too hard to do for a complete idiot. Where are you located?

[idontknow]

I thought as much!

I'm a couple of miles from brands hatch