Evening all, a few days ago i posted up i was having a few issues with the 3dr. She'd suddenly started to missfire when coming on boost.

Since then i've done the following:

Changed fuel pump
Changed Fuel filter
Confirmed good Voltage at pump
Changed fuel pressure reg
Changed Map sensor
Changed Phase sensor
Changed Plugs
Changed Crank sensor
Changed Water coolant sensor
Checked dizzy cap and rotor arm (both look in good nic)
All sensors/plugs etc gapped correctly (using info off this site)

And STILL it missfires at me!! I'm not 100% but i think its overfueling when it does too, as when it first started to miss i checked the plugs and they showed a good burn, since i've been trying to solve the problem and test driving the car down the road and back its coaked the plugs up black now??

Whats left to look at, could a HT lead give issues only coming onto boost? One of my leads is "suspect" as it looks a little "rough" Car drives fine off boost, i know the spark increases on boost doesnt it?

Maybe ingnition amp also?? Am clutching at straws at the moment to be honest


Anyone got any ideas? Spent a fortune so far and got nowhere!

 

Try some decent HT leads, or try to borrow some from someone local.

 

HT leads can break down under load

 

Sounds like mine,i was going round in circles,was mis-firing(was virtualy cutting out) on when you floored it,then it sort of drove through it.I must of spent £500 trying to sort it.Eventually i took the car in for a look,they re mapped it,completly sorted it.cost me £320

 

Wish i could mate, cosworths few and far between round my way, looks like i'm going to be shelling out for a new set of leads and cross my fingers

I'm kicking myself as i had a spare original set which i sold to a lad only a few months ago!! Doh!! Would have been perfect to test the theory with too

 

I had this years ago and it was 1 of my leads

Steve

 

I had the cossie misfire issue for ages until i purchased the MSD coil pack conversion with a set of genuine 909 leads and never suffered since best mod to do to a cossie.

I only run mine on 071 plugs too at over 400bhp

 

Word to yo mumma!

 

I had this poplem over last Xmas and i did the same as you put the fucking lot on and it turnd out to be the new HT leads that i had on it which were new ford leads . you could try moveing the leads so there not nere each uver and dont have the coil lead nere the map as im told it will play it up

 

I think one of mine may have gone at the point where it connects to the plug, noticed a little tiny silver cirlce on the side of the lead (the bit that goes over the plug) i noticed that in the middle of this small silver cirlcle was a tiny split in the rubber casing, i took a torch and looked inside the rocker cover, i could see that a corresponding circle was visible on the head where it surrounds the lead, it looks as though the lead has been arcing off the block and the silver circle on the lead is a small burn mark i think.

I did try a quick and easy fix by insulating the lead with black tape (very bodge it i know but worth a try) this hasnt helped at all, but if the lead is damaged internally then i suppose its just knackered