Right as some of you will know I've been swapping bits over to try and cure the misfire my RS suddenly picked up on the way home frm Trax

So far I have tried swapping dizzy cap, rotor arm, plugs, leads, TPS, dizzy...

2moro I'm changing the chip, fuel filter and maybe injectors, other than that I'm out of options...

anybody got any suggestions as to what it might be?

It seems to be between 2-3k, as soon as it boosts it feels like it clears and goes ok.....

I'm beginning to go mad now, wanted to put a brick through the fooking thing earlier

 

top for mr wes!

 

Get it to a tuner mate, imo

 

Gis a proper description Wes lad

 

I'm worried it won't make it to a tuner, plus I haven't got endless amounts of money to spend

 

i had an annoying problem similar to that when i had a S1 RS, it was traced back to the bottom boost hose being knackered. So when it came on boost the hose blew up like a balloon, caused me major headaches trying to find it & it was a pain in the arse to start aswell bcos it wld overfuel on startup and just flood.

have you maybe checked the wiring to the injectors?? they get very brittle eventually and if theyve been on / off a number of times in the past its poss the insulation may have cracked and it cld be earthing out???

 

Are you saying it only missfires between 2 and 3K OFF boost?

Its not as simple as plug gaps too small is it? Set em to 0.75mm Minimum.

Also, check the plug on top of dizzy as the engine lurching may be pulling a poor connection into a better position. Be aware that the dizzy OFTEN causes issues like this as the internal trigger begins to fail.

 

I can actually hear the misfire through the zorst, then it starts to boost and it literally goes back to normal and really picks up...

2 of my mates have suggested it may be the cam as they have had similar problems with low down misfires

Just been out in it and taken the plugs out straight away and there was a horrible unburnt fuel smell out of number 2 plug hole, so I guess they may be right

I'll get hold of another cam today and start to rip the head apart...

 

I was gonna say spark gap

What plugs are you running ?

 

But does it run ok?
Is this a noise more than anything else mate? Are you a perfectionist and trying to sort it before it worsens? Or is this affecting your ability to drive her?

 

Champion C57Cs at the mo...

 

I had a miss fire on my old turbo and replaced everything and still no joy. The end result after i nearly burnt the fooker was the fuel accumulator spring had come loose and was causeing fuel starvation put a new one on problem fixed then i sold it

 

Stu its affecting they way it drives and I'm pretty sure its running hotter because of this, when the misfire started on the way back from Trax it was on about 3/4, but when it was ok and I was stuck in the queue to get in for an hour it wouldn't go above half way

 

Have you checked compression on your engine. I got such a similar thing goiong on at moment.
I found I only had between 0 and 3 bar on my 1st cylinder.
Still trying to find where compressiongoing

 

Yeah have done a compression test mate, first thing I did when I got home. I forget what they were on now but they were all within about 8psi of each other

Just been on the phone to my mate and he's got a barely used Piper 285T2 sat in his garage, he's dropping it round to me 2moro so I can change it over.

Thanks for all your suggestions guys, much appreciated.

Lee sounds like your head gasket has gone mate....

 

Try some BCR8ES cheapo NGK plugs Wes before you rip her apart......

 

Ok Stu will nip down to Lucas in a mo, cheers

 

The Race plugs are a finicky bugger and may be your problem from what you are describing..

It can indeed be a cam problem though as CVH tends to take No4 lobe of resulting in unequal power from each cylinder and an inherant miss on some cylinders.

 

Wes on Russ's pc...

Well rain stopped play today (but not on the bike )

Gonna get going on it 2moro and ditch those plugs

 

Oiiiiiii i use them plugs

 

My misfire on my old S2 turned out to be worn cam lobe.

If its got a Piper in it, I'd try that, think they are notorious for it.

 

UPDATE: Well the car has just limped home, I've now dumped it outside and I'm prepared to let it rot.

I changed the plugs today for the NGK8s and that made fook all difference, what I did notice however was number 1 and 4 were soaked, even though the car had been standing all night, is this right?

I pulled up at a junction earlier and the oil light flickered on, revs didn't die though, then the light was on more than it was off. Parked it and did some bits in town, came back and it wouldn't start for about 2 mins...

Now all this combined with the misfire really makes me wonder if the bottom end has given up. My mate had exactly the same problem with his engie and it turned out to be a crack inbetween bores 3 and 4...

Now I've got to make a decision, do I bring forward my planned engine swap (low comp 1.6) or do I try and get to the bottom of the problems I having with this one, bearing in mind there are no tuners over here

ANY comments welcome...

 

no wes u get a 1.9

 

take cam out mate, easy enuff. Also do a run with reg disconnected

 

reg?

 

you need to find the problem before you build another engine though.

is it rattling at all? sound top endy? if the cams gone then it may well of put some nasty stuff throughout your engine!!

mine did when it ate itself!! you should seen the amount of metal that come out of the oil filter!! though you could really hear it rattling fooked.

 

fuel pressure reg

 

BTw.. half inch plug gap runs sh:t rick any better suggestions?

 

yes - u need to weld up ur combustion chambers as they may have been a little stretched with that sort of gap...

 

yeah yeah done that already....





wes... where you gone??!!

 

there's ur prob. Ur too busy tring to relocate the valves - uve forgotten that u still need plugs!

 

take the dizzy cap of and have a look inside the distributor there is 3 wires thay sometimes come loose and get cought where the rotor arm turns ive had that problem once.

cant remember now but isnt there a filter in the tank on the end of the sendor unit ????

check the fuel pipe's ????

 

I've changed the dizzy for another one, I knew it was a working one too

Well I've had a lengthy discussion with my mate last night and we've decided to build the low comp lump properly, new shells, pumps, gaskets and everything so this engine is going to have to do me for another couple of months while the other one is being sorted.

Its booked in to see the bloke who helped sort Darrens Martini Esc Cos, so it should be in safe hands and hopefully he'll be able to tell me what it is, and the engine will be around until the new engine is built.

Also around this time I'm hoping that Simon will have put the finishing touches to his S8 for the ERST so I can ditch the fuelling and dizzy system and run proper injectors and go for something a little more reliable and mappable.

Then I'll make the huuuuuge trip to Stu to map it

So if anyone wants to donate any cash my way, I'll PM you my Paypal name

Thanks for all your suggestions guys, I know I've been a little vague with my descriptions...

 

did you check the fuel pressure on it

 

i think he's off checking his plums!!

 

oh dear i bet he is pissed of i would be

 

You got that right

Everything such as fuel pressure is going to be checked when it goes into the garage. I'm not using the car for work or anything now, thats what the bikes for

 

never mind good luck with it mate and let us know what it is.

 

Right well an update, took the cam out today and no.3 inlet lobe has had about 3mm taken off it

changed it for a standard cam now and she runs lovely, going to do an oil change 2moro night to get rid of the swarf that I know is gona be somewhere in there...

Only thing I can put it down to is the oil getting too hot and thin on the way into Trax...

Ah well another cam will be here soon with the head so onwards and upwards

Thanks to everyone for their suggestions

 

nice one wes!- top stuff!