5 replies to this topic

[minicooper1.3i]

Hi

If any of you have been following my other thread on the misfiring MPi, you'll notice that I've checked, changed and tested just about everything I can think of without any sucsess. I'm begining to think that the ECU is dud. I thought they were pretty indestructable, but I'm really struggling here to find new things to check. In brief, I've got no spark going down the HT leads, despite there being a 12V supply to the coil pack and the wiring between coil pack and ECU (159/25 & 26) checking out OK. I've also changed the coil pack but I haven't tested it on my other MPi yet.

Assuming it's ok, what are the chances of the ECU being fried? How can it be tested? And if it needs to be replace, do I have to replace the alarm module / key fobs at the same time?

Really need some help here please people

Many thanks!

[elvisthepizzaman]

go test out the coil pack on the other mpi...perhaps the main relay is just stuck, swap it out with the working unit from the other mpi after you test out the coil pack.

EDIT: I just reread your post and the new updates. You have to have the ecu coded with the alarm module and key fobs at the same time if you get a replacement ecu.

Edited by elvisthepizzaman, 06 August 2008 - 07:44 PM.

[minicooper1.3i]

I'll put the spare or original coil pack on my working car tonight and see if I get a spark. I've already changed the new bought leads with the ones on my current car and they're fine.

One question, do the spark plugs earth against the cylinder head? And if the earth isn't good enough, would this prevent a spark? I am getting an earth reading between block and body, but maybe it just isn't good enough (clutching at straws here it you hadn't guessed)

Cheers!

[elvisthepizzaman]

The ecu grounds the coil pack through the other two wires. It takes in the sensor readings and through its coding it grounds each side of the pack according to when it is required. Yes the plugs earth through the head, thats why you have to hold the plug against the body or engine to get it to spark otherwise you become the grounding point. If you get a reading then thats probably good enough to fire the plugs off of.

[minicooper1.3i]

Oops...I'm kinda double posting now with my other thread

Do you know which pin on the ECU plugs the coil pack earth comes out of, once it's been in on the B&W wire? As I'm getting a *rubbish* earth reading of 500 ohms or there abouts.

Cheers!

[minicooper1.3i]

Scrap the above comments. Have just tested the earth to ECU on my other MPi and am getting exactly the same reading. When the ign. is set to accessory there's a resistance of about 500 ohms on the coil pack earth wire.

Back to square one

What the hell is stopping if from sparking???????????