Alright folks,

my cossie has a missfire to it, heres what i have done to check her out :

put 4 new plugs in the car
new ht leads
checked plugs sparking by attatching them an earthing them - all fine


I had the car parked up for a while after it started running rough last year.

I started her again today, first of all she was missfiring as usual like before.
However no 3 lead wasn't doing anything sorta thing. While its running i can pull off an reconnect lead no 3 closest to bulkhead of car and it made no difference.
I then removed plug no 3 and this was a brand new plug i'd just fitted 5mins before, it was now black and sooty from the top, no oil or wet just black an sooty.

Also when i started it today, i found it chucked blue smoke out on startup and as i rev'd it smoke came out. But i now find the smoke has stopped being blue and on idle the smoke coming out whilst missfiring is black an smells of fuel.
I also noticed while running shes had black sooty smoke appearing from around the turbo downpipe that attatches to the turbo, so there was some smoke coming out whilst it was running an missfiring away

Can u guys help me diagnose it, as i'm not to sure at the min

cheeRS in advance peeps

 

valve on 3 not sealing?

 

thats what i thought aswell.

I just been out again and her running again. Removed all 4 plugs again, they are all black sooty coated.
However no 3 is still the dud one, and while it was running i pulled the leads off no 1/ no 2 and no 4 and they all made it run very poorly. But when i tried with no 3 again it made no difference at all to the running of the car

sound like where getting somewhere peeps?

cheers again

 

do a com test on them b4 you go any further

 

don't know which one i need to do, is it compression test or a leakdown test.

any ideas an whats the difference between both?

 

just got mate to do check come out as

140/130/120/130

does this point to anything else now

cheers

 

Should run on all 4 with those comp figures
If you have a spark on no3 pot then check the injector for no3 isn't fooked!

 

crack in your dizzy cap? what leads are you using?

 

blue ford motorsport leads.

I'm going to get another check done on the compression, cos his tester thing did look quite old, it was his old mans an he bought it round as it was in his garage. I never felt 150% confident with the outcome, but thought i'd post up if it was indicating anything else u see. had like condensation in the glass of the display an stuff.

we checked the injector out aswell and its mint an runs fine.

We did notice that the engine seems to idle faster while its missfiring an running.



I think the basic understanding to get round is why will the plug an lead on no 3 when its all plugged up normally not fire :
I.e piston ring failure could this cause the missfiring, burnt/bent valve, cracked valve with abit missing off it?

gonna check it again in the morning to see if it blue smokes and then clears up and continues with black smoke which being unburnt fuel would point to something in line of no 3 i.e ring, valve, spring lifter or something


Also if its running to rich what do u need to adjust to lower the richness sorta thing. I will obviouslly be getting it setup aswell if i can get it going properly? Think its the fuel pressure regulator

cheers folks

 

your blue smoke on start up is more to be valve stem seals

the misfire you say that when u pull the lead off it doesnt do anything

have you tried checking the lead to see if it sparks the plug

possible lead failure id say

could be cap and rotor need changing aswell

 

i'de check the dizzy cap, if its been left stood, there is probably condensation inside the cap - a 2 min job that doesnt require any tools to remove /refit


wipe any excess water out, then use some wd-40 to expel any moisture and then refit - if it still does it - i'd try a new cap and arm, about 15 quid for the 2

 

alright peeps, the cap is new an rotor arm. i checked the cap yesterday, still no luck.

The leads are all sparking. Even no 3 lead sparks aswell. I took no 3 lead off the plug pushed another plug into the ht lead and rested it on metal on the engine i.e earth'd it. Then cranked it over and the lead is working and the plug is sparking. IT just not doing it when the plug is screwed in, OR it is sparking but a valve or something broken inside is not allowing it to run right due to incorrect combustion or valve not sealing or seating properly.

Any thoughts on this idea folks?

cheers

 

with those compression figures, combustion isn't leaking past a valve or ring enough to cause a misfire. Might sound silly, but all the leads are on the right plugs?

 

hmmm, leads are correct, or if anyone has a picture showing where they should go i will double check.

cheers

 

 

might be a injector or plug to the injector check your loom as well

 

right just been out and investigates further. My ht leads were on different to above diagram.

I have now refitted them exactly as the diadgram shows.

I also took the rocker cover off to see if there was any damage inside the head that was visible but nothing at all.

I then put Ł5 worth of optimax in her as fuel needle was very low

also cleaned the dizzy cap with cloth and plug connection to the dizzy itself



I have tried starting her up now after all this, but she just keeps cranking over now and won't fire at all or run.

HELP PLEASE!

 

check to seed if you have a spark now mate

could of disturbed something in the dizzy maybe phase sensor?

if you dont could be crank sensor playing up try cleaning that as these always get dirty from where they are

if u have spark check the fuel again

carnt think of anything else it can be

 

as said above those figure are good enough for it to be running on ALL four cylinders, I dont think if a valve/valves wasn't seating you get a reading as it wouldn't be sealed.


have you checked the spark plug thats in the 3rd cylinder is correctly gapped or even sparking?

 

yep, if now no spark, crank sensor is favourite

OR...

you have dropped the little carbon tip that is spring loaded into the cap of the dizzy when u took it off... is this this in there?

 

right checked again.

I have checked all 4 plugs attatched to their individual lead and earthing them aginst the engine, they all have a spark coming to them.

the plugs after endless turning over smelt of petrol and were damp with fuel.

My dad reckons cos i took the rocker cover off and the plugs out, the engine has lost its compression sorta thing.

He thinks it needs to be tow started as its getting fuel an spark.



Also when u keep turning it over, it makes a bang sound in the engine bay which sounds like a release of pressure

sometimes u get a little puff of black smoke an soot just from around the turbo downpipe bolts

and when i turn the key off to take it out u get a puphh or puhh kinda pop sound from the exhaust

any more ideas

cheers again guys

 

you hasve the firing order wrong


double check

it sounds like its trying to fore backwards

 

now that DOES sound like crank sensor, mine when it was messin abuot went witha right bang due to the coilpack and flames uses to shoot out the back on startup

try to disconnect it, the white one on the bottom pulley, you will probably find all the grease that is there to keep the moisture out and act as a conductor, has gone dry and hard and now acting as an insulator,

 

i assure you folks the leads are exactly as the above diagram shows.

what i don't understand is yesterday it was running fair enough an was missfiring, today after putting leads correctly an cleaning plugs up etc it won't even startup, how bewildering and don't give u much confidence for reliablity, lol

strange

 

i see what your saying mate but its a ford cosworth

as above then if the leads are on rite check the crank sensor have you got all the lugs on the pulley?

could also check the ignition amplifier aswell on the passenger side inner wing

taking a rocker cover off isnt going to lose compression, the car will fire up with this off but u will have loads of oil everywhere

 

hmmm,

so need to look at crank sensor, ignition amplifier, lugs on pulley

in each case what shall i be looking for exactly? or shall i get my electrical tester that i normally check car battries with an check for current figures

cheers

 

so u've got the leads on as per the pic, and yours is a rear facing cap, not a vertical 4x4 one...?


there should be 4 small lugs on the bottom pulley, equally spaced around it and the gap between the lug top and the sensor face shouoldbe 0.6mm

first i'd try unpluggin it though and squart some carb cleaner inside both connectors, make sure its clean..

 

ok i have a 4x4 bottom end, but y cap is the one in the pic, so where u push the leads on faces the bulkhead as in ur pic.

will check the crank sensor tomorrow


when cranking over should u have a constant spark all the time? mine sparks sparks then kinda stops an then starts sparking again.

When u crank it over it doesn't spark continuoslly while its being turned over non stop.

is this anything to do with the prob?

cheers

 

if the car ran then it didn't run when you put the leads on as per the picture i would be under the impression that you have put the leads on wrong. it could be possable that the distributer has been taken out in the past and not put back in the right place, put the engine on TDC no.1 cylinder and check to see if the rotor arm is pointing at no. 1 lead on the distributer cap.

 

i have put the leads on exactly as in the pic supplied.

To bring it to tdc do i need to put a spanner on the crank pulley and bring it round, where is the timing mark for the crank pulley whats it look like.

or manually just bring the 1st piston to the top and then check where the rotor arm is pointing

cheers

 

you really need to take the cam cover off again, turn the engine with the crank pully untill the front edge of lug on the pully after the timing marks lines up with the pointer on the block, make sure both sets of valves on no.1 cyl are closed, that cylinder should be firing i.e. rotor arm pointing at lead on dissy cap. if the valves are not closed on no.1 cyl turn engine 180deg and check again.

 

hello ppl, i am having the same problem now but i will post my own post in a min.. cos i am not gettin a spark on 1/2 plug.

anyway this is the best way to see if your crank sensor is working disconnect it from the engine plus unplug it from the loom, then once in your hand plug the loom back into the sensor and then just hold it to the engine or anything which will ground it to the car.

by the way make sure you have the ignition on, if its working you will hear the fuel pump purge and relays click, plus if you need to check the phase sensor is working then just leave the igniton on un plug it, then plug it back on you should hear the same as above.

now ppl please take time out on my post i have come to a point where i am bangin my head now.....

 

ok just messed about withthe leads and reconfigured them, and i got it started and runnning exactly the same as it was before, still missifiring on no 3 though

crank sensor is brand new, phase sensor is brand new

any more ideas?

when u rev it up it sounds like its ok, but on idle it pu puh puh puh puh pop puh puh puh.

it revs nicely and doesn't continue missfiring through the revs .

It does idle fast though, approx at about 1500rpm

 

map sensor sounds next likely.... is it a 3 bar one...?

they can be a problem, but yet work fine on another car....

 

have u tried driving it, if it is the map sensor making it run rich, aquick poke of boost may make it run ok again... just thinking cos its been stood.. does the misfire carry on through the revs and when it comes on boost?

 

check the inlet manifold gasket

 

JUST HAD MOBILE MECHANIC OUT TO DO A PROPER COMPRESSION TEST. HIS READINGS WERE :

90/90/90/90

Now what does this mean? he just said thats low

cheers folks

 

hey mate dont know about compression but alot of the time in the past i have had sticky injectors hence black smpke and over ,overfuelling also causes a missfire and carboned plugs very most likley


can u smell petrol much

 

car is running very rich i assure you, its black smoking out the back and the plugs are just getting black an sooted very quickly.

But i put a brand new set in and as soon as i started her up she was still misfiring.

So folks whats does this indicate if the compression is reading 90/90/90/90 after mobile mechanic checked it out properly?

cheers

 

it could be the map sensor or the ect sender(located at the rear of the head on passendger side) regarding the rich running!

90 psi across the four??????? that does seem abit low but as their ALL the same it would still run on the four I would of thought


what is the spec of your car standard or low comp etc?