Chaos

Compression test was one of the very first things I did. All cylinders good. Gonna send ecu off for testing. What would cause an ecu to fail? And how can I prevent it in the future?

Cheers Dave

had a mechanic friend of mine plug his reader in. All it said was cylinder 1 misfire. Even did a read with engine running and the same. It’s almost like the ecu is telling it not to fire for some reason. I think I have eliminated everything else?

Ok so checked wires to ecu. I have resistance from ecu to coil pack. Took number 1 leed out and put in to number 4. Put number 4 into 1. Number then wouldn’t fire. Swapped the leed out completely for one that I know works and still won’t fire. Would this be an ecu issue? And can I just put another ecu in (plug and play)

Any help appreciated as scratching my head. Run codes and came back cylinder 1 misfire, tried a better code reader and discovered that there is no spark to cylinder 1. So cylinder 1 not firing at all. Things I’ve done

changed spark plugs

changed leeds

changed to a brand new coil pack

still not firing

where should I look next?

52 minutes ago, Greydog said:

Hi Carl

Welcome to the Forum

The simplest check is to move the coil pack if the misfire goes with it you have your culprit. If the misfire remains then I would suspect the harness not unknown for them to become chaffed and cause misfires. Also check the Injector harness while your there

If you have a diagnostic tool such as INPA you can run live data to check

Good luck tracking it down

Dave

Cheers Buddy

I will try that out this evening. I’ve only got an obd2 reader. Is it really worth investing in an INPA?

Hi all, little help please.

I’ve got a 1999 z3 1.9 and really enjoy working on the car. Have code cylinder 1 random misfire. Mpg is horrendous, strong smell of petrol, lack of power and sounds like a tractor.

things I’ve changed.

valve cover gasket as cylinder 1 spark plug was covered in oil (solved now) also several hoses that were perished.

all spark plugs

all injectors and fuel rail

fuel pump

fuel filter

crank position sensor

Next step is injector coil and Leeds.

is there anyway of checking the coil pack and Leeds to make sure they are functioning properly?