misfiring,shaking engine ph2 172

[cruffy69]

need to pick everyone's brains,
fitted a new coil pack 2day as mine old one had cracked/split all round!

started car found still running rough (misfiring) rev the car and sounds like a lawn moer!!! changed plugs - not made any difference

connected obd reader, checked fault memory = cylinder misfire not spesific

any ideas please help

 

[Ad172UK]

Generally they all run quite lumpy due to the cams and output of the engine.

Did you change the HT leads along with the Coil pack & Plugs??

 

[cruffy69]

no i havent changed the HT leads yet i was thinking that culd be the problem, i tried to check the continiuty threw them with multi meter but couldnt get reading! then was told you cant do it anyway.

 

[Brasseye]

silly question but the leads are in the right plug order ?

 

[cruffy69]

yeah checked that the've got white dots 1,2,3 &4 from left to right and im a hgv mechanic lol!

 

[Ad172UK]

Tried checking the plugs are sparking?

Most probably HT leads if it's running more lumpy than the normal amount.

 

[cruffy69]

no ill try that 2moro got dark & i got hungry lol!
its defferently running more lumpy than usual like 3 cylinders! the more revs more tappy it gets if you no wot i mean!

could it be a crankcase sensor???

 

[cruffy69]

i meant crankshaft sensor or poss lambar sensor???

 

[Sean6545]

You do know that cylinder number one is the gearbox end?

 

[cruffy69]

no i didnt but there marked 1-4 left to right and the shortest one wont reach any where else bar the left one

 

[cruffy69]

so from g/box side right - left is 1,2,3,4 just checked HT leads tht seems all ok :S

 

[Jonny1*2]

no the leads run 1-4 from left to right mate. You will be able to tell as the length of the wires aren't long enough to go the wrong way.

 

[cruffy69]

number 4 goes nearest the left hand side cos it dont reach

 

[Jonny1*2]

hmmm, I labeled mine when I removed them and left to right was how I did it. Go off the cable length then mate.

 

[cruffy69]

just rechecked HT leads the dots go 1-4 left - right the leads order goes from g/box end right - left 1-4 if you no wot imean its hard to explain!:S

the fault code is p0314 if tht helps anyone

 

[barny]

Have you tried checking for splits in vacuume hoses, this just happened to my girlfriends merc and a new hose later and it runs as it should.
good luck!

 

[cruffy69]

thanks will check hoses 2moro open 2 any suggestions just want it fixed!

 

[BenStanley]

i had a hole in one of my vac pipes replaced and still runs like s**t. As if its missing, spitting from the exhaust and jiggles the car to fook!

 

[Jonny1*2]

just rechecked HT leads the dots go 1-4 left - right the leads order goes from g/box end right - left 1-4 if you no wot imean its hard to explain!:S

the fault code is p0314 if tht helps anyone

Yeah that makes sense. I presume you didn't remove any of the vac hoses when you did the leads? or did you completely remove the plenum? Did you change the gaskets if so?

Also, is the coil pack you got new? might also be faulty?

 

[cruffy69]

i didnt remove ay vacuum hoses, just removed inlet manifold to one side, didnt change gasket as metal & seemed ok

the coil pack is brand new fron renualt dealer.

put it back together 2day found it running lumpy till it got warm thn seemed to carm down connected obd reader found unable to turn MIL light off as due to fault still on the fault = SINGLE CYLINDER MISFIRE im more inclind to say faulty HTleads????

 

[Jonny1*2]

could be faulty new ones yeah. probably should get some new gaskets really, but it wouldn't cause the probs you're having.

 

[Alpine_motorsport]

mines doing the same thing with i think the same fault code. I ve found that injector No 4 is not firing so got a nice job this weekend tracing that......

 

[cruffy69]

CAR IS NOW FIXED fitted new ht leads 2day yyeeeaaahhhhhhhhhhhhh

thanks for everyone's help and advice

 

[Ad172UK]

I got one right for a change!

Well chuffed lol