bassboy

Hi guys, I have a problem with my Focus RS mk1

The car is jerking when on light throttle anywhere from around 1 1.5k upwards...

If I hold the throttle at say 1-3.5krpm, the cars drive is pretty jerky, but its not missing!

The car does it noticably more when it has warmed up...initial driving (from cold), car seems to drive ok...but when it gets warm and come onto boost a couple of times (even 2-3psi), it then will seem to do its jerky stuff...

Things I have done/changed so far...

Put the OEM map back on - No difference
Changed the MAF sensor - No difference
ITV24's gapped to 0.7mm - No difference
Genuine Ford plug leads - No difference
Changed the turbo - maf pipe for a Roose item - Cured the boost problems I was having at high RPM
Changed the one way valve pipe on the inlet for a Roose item - No difference

Now, one thing I have removed was the atmo dumpvalve to help diagnose my boost problem...I havent since put one back on as im awaiting some 25mm hose to arrive.

Could the lack of dumpvalve be causing this?

Also, if it were something like the coil pack for example, it would be missing constantly wouldnt it? Or just pack up altogether?...not only doing it when the car is under light load?

Thanks for any input as this is driving me nuts now!

bassboy

Update guys...

changed the TPS and still doing the same thing....
ECU reset...same problem

This is what it does on idle...it has always done this however...so the main problem is the slightly jerky drive on light throttle...

[media]http://www.youtube.com/watch?v=vBrMG4JSEoo[/media]

Update

Removed and cleaned ICV - let it soak in degreaser over night and gave it a thorough clean
Changed coil pack
Cleaned throttle body
Changed TPS
New fuel filter

Problem still persists.....

Anyone else that can possibly help?

Could it be a Lamba sensor problem?

I have also noticed when giving it some stick, after a gearchange, the car seems lazy then when its on boost it tears up the road again....

Thanks

bassboy

bump

Zetecfiesta

what fuel you got in it? mine was doing very similar a while back id filled mine up with full tank of tesco's and it started doing this, fitted a new MAF as thats what everyone said it was but it still did it, went and filled it back up with bp ultimate and its almost cleared it straight away!

id try on FRS section on RSOC you will probably get more help!

vaughant

iTrader: (1)

Have you read the fault codes fella?the focus stores data even if the em light docent come on,i found the faults on my old 2.0l estate that way and it was bang on.

bassboy

Zetecfiesta - there is Vpower in the car...new fuel filter to (although that wouldnt help if I used a mixture/crap fuel LOL!)

I also did change the MAF to no avail...and the TPS, and cleaned out the ISCV etc etc

It did have Super unleaded in, but I filled up with Vpower about 10miles before the petrol light came on...since I have done around 10-15miles....

vaughant - We checked the ECU for errors on a number of occasions using around 5 machines - Bosch, Snap on, EOBD scanner, Dreamscience, Superchips BF, and the built in diagnostic thing on the dash....all came up with 0 errors!

Zetecfiesta

hmm im stumped then, i dont really know as their is so many things that can go wrong!

bassboy

Properly getting on my nerves...I mean look at the amount of things ive tried LOL

And the ISCV aint exactly an easy job dispite it only have 2 8mm bolts and a connector PMSL!!!!!

Over on the RSOC, they still think it could be an ISCV issue...reckon I should bite the bullet and just change it?

RichieST

iTrader: (2)

The revs dropping low almost at stalling would suggest a sticking ISCV.

Hesitation through the rev range could be lambda sensor related. You say it is better when the engine is cold. I don't think lambda sensors give an output until engine is up to temperature so it could be this. You could always try unplugging it and see what happens, this will bring on the engine management light but should pinpoint if it is faulty or not!

bassboy

Rich, disconnecting it was my next point of call...however, do you know how the car will drive (in general i.e all things being well) if the Lambda is unplugged? Will the car go into limp mode or drive 'silly' if its disconnected?

Also the car has been de-catted...which lambda should I disconnect lol?

RichieST

iTrader: (2)

If you unplug it the car will go into limp home mode, you may find a reduction in power but it should drive smoothly. Just disconnect the battery for half an hour or so to wipe out any fault codes afterwards. It is the pre-cat lambda sensor, the sensor after the cat just monitors the performance of the cat, it doesn't give any reading to the ecu.

bassboy

Quick update guys...

Disconnected the Lambda sensor and it made no difference again...and the EML didnt come on either...mind you I only drove it for less than a mile I would think...

I have a new ISCV here so I will try fitting that tomorrow and see how it goes...

Also got a 25mm hose coming from Roose so will put the OEM dumpvalve back on just incase thats causing any issues..which I cant see how?

bassboy

bassboy

Fitted the ISCV and its made no difference...

Also tried the standard map again and made no difference....

Dont know what else to try now

RichieST

iTrader: (2)

Probably best to get it on a diagnostics machine mate that reads live info, so you can see what all the sensors etc are doing. An hours labour spent is gonna be cheaper than throwing parts at it!

JamboRS

why not get it on a set of rollers mate
sure a decent tuner/rolling road will find the problem

bassboy

Yep, think ill ring PE up in the morning as they are only down the road from me...

Would book it in to SCC but they are a bit of a drive away but might just bite the bullet and take it there

bassboy

We have the facilities to do this, however, we dont know what values we are looking for from the sensors....unless you know someone who can help?

Big Will_

Feel free to send any data you get over - i might be able to make something of it.

Another thing i'd suggest is putting a wideband fuel monitor on and seeing what AFRs you've got. Fuel pump approaching failure could give behaviour like this!

bassboy

Hi Will, thanks for your input...would it not behave oddly when its on boost to? Ill get it on the rollers or something and get back to you asap!

tatslife

hi my 2003 rs focus has same problem,when car cold car is fine,when heated up under hard boost car gets up to about half boost then sounds like a misfire and you get a puff of black smoke,no fault codes ,new plugs and leads fitted,could it be boost sencor??please help

H15 FSC

i had this problem and it was the fuel filter, but not the normal one, theres one on the fuel pump in the tank,
i took the pump out, run fuel through it with the filter on and then off, and it was restricting the flow, cut off the filter and it ran fine,

Shonkey555

Did you ever sort out this issue bassboy? I have exactly the same issue

kevin1987

Hi Guys, I have the same problem. Ignition coil, cable and spark plugs I exchanged without success. Fuel pressure is ok. The pressure also increases during acceleration to about 3,5bar. Does anyone have any idea what it could be?

I Run Sabre Stg.3
380S Turbo
650ccm Siemens Injectors
DW65 Fuel Pump
Sabre Mapped ECU

COLEYST200

iTrader: (3)

Have a look at your water senders as I had this prbprob on my cosworth and it turned out to be the blue water sender telling the ecu the engine Temp,s
it could be worth a look mate .

kevin1987

have just tested this with a ohm measurement. Cold he has 35Kohm as soon as he gets warmer the resistance decreases. at40 degrees celsius, I have 13 kohm so the sensor is not the problem

t230

couple things you can check:


1) Do a wastegate check (disconnect boost pipes from actuator and turbo, disconnect boost solenoid ) BUT DONT BOOT IT , just give it a little blip see if that cures it - DO NOT BOOT FULL THROTTLE YOU CAN BLOW YOUR ENGINE and try this at your own risk

2) Try a DW fuel pump - this also copes with tesco 99 octane - as i noticed this with standard pump

3) Third possible thing - which is what happened to me is that no matter what reset i did it stayed in limp mode till i had it live mapped - which is the best thing to do - take it to someone who knows what they are doing instead of chucking parts at it - ive been through about a million coilpacks - in the end went MSD so fit & forget....

kevin1987

Hey thanks a lot!

1)How exactly do you mean that with the wastegate? Do not understand your english really sorry, and What means Blip? Do you think I should have a look if it is the problem of boost?You mean I should reduce the boss? and see if there is a change?or exactly the other way it makes it so he gets more boost?

2)
The fuel pump is new. installed for about 1000km. Fuel pressure is okay that's what I've tested.

3)
The mapping is from Saber and was silenced on the component. Do you mean that my ECU always runs in the emergency program? I live in Switzerland and the next one with experience of Focus rs mk1 is in Germany 600km away from here ..

kevin1987

Guys these things are getting really crazy. I have today installed the ignition coil, cable and sparks of my friends with my rs1. did not do anything. the parts are again dismantled and now the rs1 of my friends is not working properly anymore! I have read the error code p0602 on the ECU. Did you tell me what this error code means?

jonfoc

kevin1987

my friends RS run great before we have installed his ignition parts on my rs. After we had the parts reinstalled with him, he had exactly the same misfires as mine...
which hose do you mean exactly?

t230

Do you mean that all new bits failed? -

bassboy

This is going back some time now, but from what I remember, I traced it down to a dodgy ignition coil, which although was brand new, wasnt sparking hard enough...switched to an Intermotor coil I think it was, and it was spot on!

kevin1987

Unfortunately, I can not tell you exactly what was broken. But I tried different ignition coils, cables and sparks and only after I replaced everything together was the problem gone.

Unfortunately, the problem has come back now. After about 80 kilometers drive without problem, he starts again with misfire ... I think something in my focus destroys my ignition coil.

boost monster