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Omega Help Area => Omega General Help => Topic started by: Eighth_dwarf on 17 February 2010, 12:15:31

Title: Not firing on all cylinders?
Post by: Eighth_dwarf on 17 February 2010, 12:15:31
Had usual cam cover leak, changed gaskets, plugs and leads. Car had been hunting on tickover for a while which I attributed to plug wells full of oil.
Going along m4 it suddenly lost at least one cylinder, no fault codes so I assumed dispack blown. Changed dispack but still not firing right.

Any help appreciated!!!

Have plugged in "My Naff Code Reader" havd have live data if it will be of any help! if someone can tell me how to upload!
Title: Re: Not firing on all cylinders?
Post by: JamesV6CDX on 17 February 2010, 12:25:44
All plugs and leads OK?

If so - check for codes - and if no joy compression test it
Title: Re: Not firing on all cylinders?
Post by: Eighth_dwarf on 17 February 2010, 12:29:29
Plugs & Leads new, no codes stored.
Title: Re: Not firing on all cylinders?
Post by: JamesV6CDX on 17 February 2010, 12:30:37
Quote
Plugs & Leads new, no codes stored.

In that case - compression test it... I doubt it's a compression problem, but you obviously need to emiminate it...
Title: Re: Not firing on all cylinders?
Post by: Eighth_dwarf on 06 April 2010, 15:19:50
update....

finally got round to compression testing it and results are:

Cyl 1 - 110
Cyl 2 - 120
Cyl 3 - 110
Cyl 4 - 120
Cyl 5 - 110
Cyl 6 - 130

as all are around the same I guess not a compression problem.

what should I look at next? replace leads & plugs again? or is there another suspected cause?
Title: Re: Not firing on all cylinders?
Post by: henryd on 06 April 2010, 15:22:52
its unlikely but it could be an injector playing up,but plugs and leads are the most likely cadidates
Title: Re: Not firing on all cylinders?
Post by: Marks DTM Calib on 06 April 2010, 15:27:39
Have you connected the plug leads to the DIS correctly....as its not as obvious as you think i.e.

5-3-1
2-6-4
Title: Re: Not firing on all cylinders?
Post by: Eighth_dwarf on 06 April 2010, 15:37:51
99% sure as I checked, checked and rechecked as I was doing it but will make sure again now!
Title: Re: Not firing on all cylinders?
Post by: Entwood on 06 April 2010, 15:47:45
If the plug wells were full of oil it is posible the leads themselves have been damaged, hot oil and rubber don't sit well together ( no pun intended  :)  )
Title: Re: Not firing on all cylinders?
Post by: Eighth_dwarf on 06 April 2010, 15:50:42
leads are connected the correct way round. Next idea please!

That was the reason I replaced the plugs and leads, because of the cam cover gaskets going.
Title: Re: Not firing on all cylinders?
Post by: Eighth_dwarf on 08 April 2010, 13:21:11
so is it worth trying another set of leads and plugs or not? Would crank sensor cause it to run rough? i.e not sparking at correct time?
Title: Re: Not firing on all cylinders?
Post by: Kevin Wood on 08 April 2010, 13:51:34
Quote
so is it worth trying another set of leads and plugs or not? Would crank sensor cause it to run rough? i.e not sparking at correct time?

It could, but you'd almost certainly have a code 19 stored.

How does the misfire manifest itself? Is it there all the time, just when cold, just when hot?

At idle, at high rpm? Under light load, when accelerating hard?

If it's always there and ignition system is fine, check for a fuel injector with a lead off perhaps?

Kevin
Title: Re: Not firing on all cylinders?
Post by: Eighth_dwarf on 08 April 2010, 14:07:13
Misfire is there all the time, smell of petrol when starting from cold so assuming a cyl is not firing.

Is a lumpy tickover and real lack of power when accelerating. Once it has droped in top at 60ish when you accelerate you can feel the serious unbalance of the engine where somethings is not fireing, if you kick it down it will slowly accel and not feel as unbalanced.
Title: Re: Not firing on all cylinders?
Post by: Kevin Wood on 08 April 2010, 15:03:44
It does sound ignition related to me. Can you pull the spark plugs out after a run and see if any are wet? That might at least narrow it down to a single cylinder.

Kevin
Title: Re: Not firing on all cylinders?
Post by: Eighth_dwarf on 12 April 2010, 10:58:22
Problem solved. Replaced leads and plugs again (found one plug had cracked when i took it out) and crank sensor.