Surprise Surprise Misfire

[Major Fallout]

Every car I have ever owned has had a misfire its the bain of my life! And because of my lack of knowledge of electrickery its always electrical.

But this time I'm running out of ideas.

It is at its worst at 40mph in 4th gear, somewhere between 1'000 rpm and 2'000 rpm on light throttle.

I cant quite make out if it still does it when it goes full loop, but it does feel down on power.

All plugs are black with carbon, not oiled up.

Up to now I have changed:

Plugs
Leads
Rotor arm
Dizzy cap
lamba sensors
ECU temp sensor
Cleaned the idle control valve thingy and made sure it moved.


Im thinking of looking at the injectors next?

Any ideas?

Would the ECU fault reader thingy help me?

[Major Fallout]

It looks brand new, is there a way of testing them? as its an expensive part.

[Major Fallout]

I did think it was shunting at first but its been getting worse, now it defiantly feels and sounds like its running on 7 at times.

I have tried an injector cleaner.

Would it be the worst thing in the world to unplug the MAF and try it down the road? And if I did what would it tell me?

If it still had the problem then it might be an air leak, or a spark problem.

Thanks for your help guys, I'm very quickly getting over my head with the electrics.

[Major Fallout]

Just gave it a go and it was a lot worse.

[Major Fallout]

Thank you but yes I'm miles away.

[Major Fallout]

Well after lots of head scratching I have given it to someone else to try and fix.

They are used to modern cars so maybe they will have more luck. Fingers crossed!

[Major Fallout]

Been doing a bit of reading and it does sound a little like the shunting problem.

But I'm sure it wasn't doing it before, and its quite a bad misfire/shunt. Its bad enough cause drivetrain damage.

I think I need someone with a Chimaera to drive mine and tell me if its the dreaded shunt.

[Major Fallout]

Well got the car back and after 5 days the cant find the problem

So its booked into Torque RVT for tuesday, with any luck Ian can fix it without it costing so much I have to sell the car to fund it.

I must apologise to Ian when I see him, as I was fuming when I met him today. I dragged him out to the car and started ranting and swearing at it, it was about 5-10min before I said hello.

[Major Fallout]

Sorry slow reply.

No drastic improvement, its still there but now I know its 100% shunting.

The latest fixes have been the plenum spacer and iridium plugs. The Plugs made a huge difference, but the plenum spacer didnt do a thing.