Aygo Misfire

[gdadbling 0]

Hi all,

I hope someone on here can help, my Mum has a 2007 Aygo 1.0 petrol and it's developed a misfire! It starts and idles fine but when you start driving it starts misfiring after about 200 yards, turn the engine off and start again and its fine for another 200 yards until the misfire is back! It's always on cylinder 3, I've fitted new plugs, swapped coils and injectors but no difference. The injector seems to be being shut off by the ECU, have spoken to an ECU specialist who said there's no known faults with these ECUs. I've also done a compression check and all cylinders are at about 13 bar/200 psi.

I'm running out of ideas, any help on where to look next would be appreciated!

gdadbling

[Spazmoid 0]

Hmm, I very much doubt a misfire is not caught in the ECU error registry by some means or another and without that data. When you say it misfires at 200 yards, what are the other variables including rev level, speed and engine load...?

Perhaps a quick test run over 200,400,600 yards at 2000,3000,4000 RPM and so on to see if you can identify a fault matrix.

Do you have access to an ECU reader..?

[gdadbling 0]

Thanks for your reply spazmoid, I have access to Bosch diagnostic equipment where I work but only read the fault code thus far. I'm having the car for more tests tomorrow so hopefully have some more info soon. I have heard the it could be a cluch fault, causing a vibration which the crankshaft sensor picks up and thinks it's a misfire.and then shutting off the injector. Have you heard of this before?

[mroth 0]

Hey guys, I have this problem aswell, how did you repair it?

[mroth 0]

Still trying to get a grasp on the reason to my engine missfire. Talked to Gdadbling about it and his car just started running smooth again, I haven't been so lucky yet.

1.) Started with a broken ignition coil, got a new one, (only the broken one is replaced) that got the car running, but it started to missfire again when the engine got warm.

2.) Replaced sparkplugs on all three cylinders, got the car running smooth even when warm, but soon after, started to missfire again when the engnine has to work harder, e.g going upphill or accellerating on full throttle.

3.) Got myself an E- Diagnose on a local workshop and they told me the code I got means missfire problems on cylinder three, no **** Sherlock...

4.) Now what?

It is still an Aygo -07 petrol.

[Raistlin 465]

What can cause the engine to misfire:

Fouled spark plug - one of the common reasons causing misfire

- problems with the ignition components: spark plugs, ignition wires, Ignition coil, Distributor, ignition module.

- fouled spark

- faulty fuel injectors

- lean air/fuel mixture due to bad airflow sensor, vacuum leaks, etc.

- vacuum leaks; examples: cracked vacuum hose, disconnected vacuum line, cracked intake snorkel

- low fuel pressure

- leaking cylinder head gasket

- low compression

- misadjusted valves

- worn valve train components

- improperly set timing

- Stuck open EGR valveEGR valve or purge valve (solenoid)

- clogged exhaust

[mroth 0]

ThanxX!

I'll let you know when I'm done!