misfire at low revs

arron_matthews

hi people i have a problem where the car is missing low down the rev range idle -3k then seems normal after that however slightly down on power.
I have done a lot of reading on this but did not want to spend loads of money trying to chase the problem just replacing loads of parts.
I have so far replaced the plugs and fuel filter as it seemed like it was not getting enough fuel through however no change. It seems like it is using tons of fuel at the moment though.
I read the coil is a common fault on these but didnt want to blow £150 if it was not that and i dont have anyone i know that has a spare to swap.
The car has been scanned no faults were found and the light on the dashboard is off.
Any ideas welcome
many thanks
Arron

Dave_Gilbert

What year n what car? Im not saying I can help but it might point to older faults.

arron_matthews

yeh sorry its a astra 2002 thanks

Dave_Gilbert

What did the plugs look like? Did they all look the same? Have you had the car long?

Some times the plugs get over tightened and crack the threads I think on cylinder 4.

im not saying thats what it is but if u had a plug that looked different from the rest it could point in that direction.

arron_matthews

All the plug looked the same. no wet plugs.
Had the car for 4 years and it has not missed a beat. it is a intermittent fault runs on at idle but does smell of strong petrol out the exhaust.

Dave_Gilbert

Id say try n get a secondhand coil that you knows good.

I think you can test the coil with op-com but I dont know how to do it.

arron_matthews

thanks again dave, i will have a look on google to see if i can find out how to do it. might nip to the local breakers and try and get a coil from them, dont know anyone else that has the same engine.

Dave_Gilbert

Id lend u mine for 10mins but its abit far.

u should be able to pick 1 up for about 40quid id say.

KevinH

Hi Arron, (@[deleted] )

Another possibility that could cause a misfire is the CTS (coolant temperature sensor) which controls the fuelling and temperature gauge.
Have a read of this thread:
https://z22se.co.uk/threads/cts-fault-no-eml-pls-read.11465/

It's also a fairly cheap part to replace - part #: 15326388 (about £11).

Stumppix

Have you cleaned breather tube between cam cover and intake tube?