Paulo P

Since I bought my 2 wheel drive Cosworth 3 months ago it's been misfiring when coming on boost

I've changed the plugs for genuine Ford ones gapped from 1.1mm down to 0.6mm, I've changed the rotor arm, I've put a 4x4 distributor cap and leads on & I've fitted a Group A coil.

It always happens as it comes on boost and it seems to spike which causes it.

When it was standard it did it and I changed it to stage 1 using a -31 actuator thinking that actuator could have been weak and I used half a hole of pre-load. I've got the standard restrictors in the amal valve and I've changed the amal valve last night for a 4x4 one.

If I back off the throttle then floor it again it clears and the car flies

Does anyone have any idea what could be causing this? I am going out of my mind with it now and it's pissing me off everytime I drive the car.

Thanks

Dave McB

how much petrol is in it??

mine can occasionally do it if there less or equal to 1/4 tank

Try fillin it up and go again..

KSA-Cossie

iTrader: (4)

What plugs paul ?

Paulo P

Just over 1/4 of a tank at the moment but fuel level makes no difference.

Motorcraft AGPS 092P's in there I think. It did exactly the same with the old plugs that were in there before but they were the wrong ones

Thanks

KSA-Cossie

iTrader: (4)

Stick a set of 071's in there gapped at 0.6mm m8.

Paulo P

What difference would that make?

KSA-Cossie

iTrader: (4)

Better plugs m8.

Paulo P

But why would it misfire and spike on new standard plugs that are gapped to that? I can understand better plugs but it's doing it on a standard engine using standard plugs. If it was seriously uprated I could see the point.

I don't want to go spending yet more money on a set of plugs and still have the same fault if you see what I mean, I've already changed quite a few parts and nothing has cured it

Paulo P

Fuel filter couldn't cause this could it? I have a new fuel filter to fit but due to the weather I haven't fitted it.

MARCOSWORTH

iTrader: (24)

Got my agps 071c gapped at 0.65mm and got a misfire,gapped them back to 0.55mm no more misfire,so it will make a huge difference.
This is on a stage 3,on stage 1 i was running 0.8mm gaps and no misfire.

rallyraid

had this prob before turned out to be plug leads breaking down internally.

Paulo P

I'm on stage 1 at the moment so I thought 0.6mm would be plenty. I will try closing the gap a little further and fitting my fuel filter tomorrow and see if that does anything.

Thanks

Paulo P

That's what I thought it was at first so I changed the leads and that made no difference at all. Everything I've done so far has made no difference

COSSIE 1

Try fuel filter and plug gaps mate should cure it

Paulo P

I will I'm going to gap the plugs this afternoon (is 0.5mm too small?) and me and a mate are changing the filter tomorrow

I can't wait to get it running right It's amazing when it does boost cleanly

bazpro

could b your phase sensor in your dizzy. my old 1 used 2 misfire and thats wot it was.

Paulo P

Can you change just that or do you have to change the whole distributor?

Paulo P

Plugs now gapped to 0.5mm and it's still doing it

I changed the fuel filter this afternoon and my old one was rotten. After fitting the new one we checked for leaks and it was leaking between the banjo and the filter on the input end to the filter and I couldn't get it to seal I tried various new washers, filing the face of the banjo to get a good clean flat surface but it refused to seal I put the old on back on after 2 hours of fiddling about and that one sealed straight away Has anyone else had problems with brand new Ford fuel filters not sealing?

What an arse of an afternoon

Thanks,

KSA-Cossie

iTrader: (4)

Yes m8 you can just change the sensor but make sure it's gapped right.

Paulo P

Thank fook for that Are they still available from Ford?

Thanks,

KSA-Cossie

iTrader: (4)

Stu at MSD sells em m8.

Paulo P

That's good Any idea of price please?

Thanks

KSA-Cossie

iTrader: (4)

http://cgi.ebay.co.uk/RS-Cosworth-Ph...QQcmdZViewItem

Paulo P

Thanks Is that what Stu sells them for too?

KSA-Cossie

iTrader: (4)

http://cgi.ebay.co.uk/RS-Cosworth-Ph...QQcmdZViewItem

Paulo P

Thanks I've emailed the seller to check how quickly they can send me one

Paulo P

Phase sensor has now been changed and the wires on the old one were knackered but it still does it

I'm getting hacked off now

Cossie Helen

iTrader: (1)

Maybe take it for someone to have a look at ?


As we spend ages going over my engine when i first got the car to see what was causing my misfire, took it to Mark Shead who found and fixed the problem in 30 mins Phase sensor wires corroded and HT leads corroded

Paulo P

I was planning on getting it remapped next month but at the moment that seems pointless I feel like scrapping it

The intercooler is on now though.

Cossie Helen

iTrader: (1)

I wished i had never bought my cra when it had the misfire, i was quite pissed off with it


Take it to someone to have a look at

Paulo P

I feel like that too and I'm considering locking it in my garage until it rots now

I've just tried calling Norris Motorsport to see what they think because I was hoping to take it there 5 weeks today, sadly they didn't answer the phone If they think they know what it is I'll continue to book it in but if they don't I can't see any point in wasting anymore money and time on this car I've changed everything I can think of now and it's pissed me off badly

I am not happy today I love the car to bits when it works but that is so rare. It's done it since I bought it

Paulo P

It's now booked into Norris for the Gunship and for them to look at it. I'm still not convinced though and I don't want to wait another 5 weeks until they can look at it, they are about 150 miles from me so I don't want a wasted trip due to this problem and I certainly don't want to waste their time, I'd rather take it them in a healthy state and get them to map it.

Can anyone else think what it could be? To sum up I have now changed the following.

Plugs (now gapped to 0.5mm)
Leads
Dizzy cap
Rotor arm
Coil (group A)
Phase sensor

The car doesn't generally misfire under normal conditions but it misfires as it comes on boost. The car is currently stage 1 but it did it as standard. The car does feel lumpy when you drive it sometimes and hesitant. It pulls cleanly comes on boost and flatspots, the boost generally goes over the 15 psi mark that it holds & lift off and the boost comes down, the misfire clears and the car then pulls cleanly.

I hope all of the information above gives a clear picture of what has been changed and how the car is behaving.

If anyone has any ideas please please please let me know.

Thanks

KSA-Cossie

iTrader: (4)

What plugs are in now ?
Is the air filter to turbo boost hose in good nick ?
Is the fuel filter new ?

Paulo P

Still the same Ford plugs in there at the moment and they've done probably 100 miles from new I'd say.

The hose is in good condition, all the hoses are in good condition.

The fuel filter hasn't been changed at the moment because when I did try and fit my new one it wouldn't seal and I have to go and buy another but I haven't had time to go and buy one yet Fuel filter is at the top of my to do list.

LukeT

Im still having trouble with mine its going to Harvey Gibbs on fri.

Its doing my head in

Paulo P

Join the club I hope you get yours sorted

Daveesaunders

Mines also got a misfire but I've narrowed it down to the HT leads breaking down as they are quite old. Mine misfires on idle and I have found its plug three causing my problems (well it would have to be as thats the only one located under the damn strut brace) once the plug gets cleaned its fine, trouble is plays up every other day at the moment

melzieann

paulpalmer

I had a similar fault it turned out to br the coolant temp sensor, Have you tried a temp sensor on it?

Paulo P

Is that the one at the back of the head?

melzieann

on a 4x4 head it is at the back but dont know if its in the same place on a 2wd head