Paul_RS

iTrader: (4)

Ok, changed, plugs, cap, arm and i still occasionally get a strange missfire around 5000ish rpm.

Sometimes it sounds like mild antilag and won't go through the miss. Loads of smoke out the exhaust too. Other times it just hesitates and goes through it and sometimes it doesn't do it at all

Could it be the phase sensor? i think its an ignition and the smoke is unburnt fuel....

charlie luciano

iTrader: (3)

which cossie variant do you have Paul?


Luciano

saff cosworth

check your plug leads...

Gordon1

what boost are you running and what coil do you have

Paul_RS

iTrader: (4)

Sorry, more details as requested!

Its a 1991 4x4

Ignition -

New group a coil
New ididium NGK plugs (also have a set of NGK 9's)
New cap
New arm
Leads are not new, but look in good condition and are genuine beru items

Its running 8 dark greens on a pectal super 8 ecu
genuine 500 cooler, hoses, inlet and throttle body. Set to hold 28PSI on high boost (has a 12 pot boost controller)

Engine loom has been replaced in the last few years as well going by the reciepts....


I was thinking about leads, but i didn't want to waste Ł80 on them only for the miss to remain.

charlie luciano

iTrader: (3)

When you get the mis-fire is the rev counter going skyward/jumping around?


Luciano

Paul_RS

iTrader: (4)

Yup it goes nuts, flys way past 7000!

I've been told the wee box thingy that attaches to one side of the coil can cause this? I left it in circuit when i change to the group a.

charlie luciano

iTrader: (3)

Not too sure on the box thingy you mention but usually if the rev counter is jumping around it means you have got engine loom problems my car started to do this and at first I cut the loom plugs out of the loom and soldered the wires together, these plugs run along the back of the rocker cover/bulk head, this lasted for about sixteen months and then the same problem came back, under boost the car would mis-fire and the rev counter would jump around/go skyward, replaced the engine loom in whole and now car runs as it should with no pesky mis-fire


Luciano

Paul_RS

iTrader: (4)

As far as i can tell the entire loom was replaced at most 5 years ago and the car has only done a few thousand miles and lived in a carcoon since (well until i got it )

But i'll investigate the loom further mate, it may even be as simple as crap in the connecting plugs!

Thanks for the pointer chum - i owe you a pint

charlie luciano

iTrader: (3)

I'll hold you to that Paul nice 1 mines a guinness

always good to help out others and pass on advice and experiences its annoying when these cars don't run right


Luciano

Paul_RS

iTrader: (4)

Dublin it is then, for the best Guinness

I appreciate the pointers - saves me so much time messing around trying to work out whats going on!

silky16v

iTrader: (1)

sound the same problems are was having with mine very similar setup also with a L8 with pectal super8 board and RS500 inlet, etc

I bought new 909 leads, cap, arm & 017C plugs, replaced the Ignition Amp also with a brand new item and cleaned off the old silicone compound off the aluminium backing plate and applied new compound this totally solved the problem.

Before hand sometimes it would drive threw it, but it got worse at night, the misfire doesn't do ya engine any favours either so be careful

I also fitted new earth from side of the head to battery and checked , cleaned & replaced all connection on the alternator, by doing this i picked up over 0.65v at the battery when light where on and engine ticking over.

I for 1 would replace the leads cause they make look ok but they could well be arching out under load.

also without fail check all sensor gaps & condition as well as loom condition and voltage at ECU

saff cosworth

" rev counter jumping "
this happened to me too, turned out to be the leads under load.
even threw the ecu off a bit leaving one of the injectors open.
get a loan of a set of leads and see if this works first...
regards paddy...

Paul_RS

iTrader: (4)

I used contact cleaner on the engine loom plugs and the problem seems to be solved

@silky and saff - I think i'll buy a new set of leads as a matter of course, that way i know they are 100%

Is there a massive difference between the 909 leads and the beru originals?

silky16v

iTrader: (1)

can't answer that the 909 leads are thicker though and new leads can't do any harm i reckon

Paul_RS

iTrader: (4)

Cheers mate

More money down the drain on the aul sierra

silky16v

iTrader: (1)

it a cossie what do you expect

saff cosworth

she can be a pain,,, but you love her anyway...

BIL N KEL

thats what was wrong with my mates car when it was happening to his