Hi, I've posted this on ffoc but was wondering if anyone on here could shed some light on the problem (Rob?)??

Right, My RS has developed a boost problem which has been getting worse over the last few months.

The car has been de-catted, Mongoose system, K&N Gen II + Bluefin.

Basically, when under load the boost peaks then keeps backing off by about 1/8-1/4 of a bar, then peaks, then drops and so on. It doesn't do it every time but is becoming more frequent. One time after this happening the car would only run half boost for the next 10 miles (rest of journey) untill the next morning when it was fine again?! Sometimes changing up a gear or backing off the throttle then nailing it again will make it hold the boost. It's not just a dodgy gauge as you can feel the car pulling then backing off.

Also, twice over the last few months when putting it under load the car has sort of misfired, banged, had no boost then all of a sudden come on boost.

The Bluefin diagnostic came up with the error 'P0234' which means 'Eng Overboost Condition' but I've never noticed it overboost??!! Anyhow, I have re-installed Bluefin to see if that makes a difference and now it's running like a bag of shit, as it did the last time I reinstalled it after fitting the CAT back part of the Mongoose system. It seemed to just sort itself out last time though?

It has been suggested that it could be the dumpvalve (running standard one) or the MAF sensor, but there was no error code for this sensor. If it is the DV I assume the only way to find out is to replace it? If so can the Focus RS run without a DV, will I get chatter??!?!?!

I've yet to take the car out for a proper drive after reinstalling Bluefin to see if it's cured (if it will eventually idle + stop missfiring) the problem.

Any idea's??

 

It's that time of the year when the temps are getting cooler and the air is getting denser. Could be that your previous safe boost is now spiking over the pre-set boostcut with the cooler charge temps ???

2p

Martyn

 

Good thinking mate. Took the car for a thrashing last night, it seems to have sorted it's running issues out + pulls alot harder than it has been of late + is holding boost fine, touch wood, at the mo. It hasn't recorded another overboost fault either. May try changing the DV anyhow for a Bailey re-circ as I've heard a strange whilstling noise a couple of times which mades me wonder if the standard vavle is leaking?

 

I think you need to fit a boost controller nath. Many member on the rsoc have already done this.

 

You can tell the RSOC was down last night


Naths gonna love you

 

hehe old skool!

 

Hi mate i am having the same problem with mine so yesterday went to the gurus at graham Goode was there for four and a bit hours i have to say these guys now there stuff, Alistar took the car out with lap top attached and after a few gremlins where sorted out the car was still misfireing at the high end of the boost scale, Turns out my fuel pump cant cope at the high end and the ecu was trying too put 50% more fuel in which is way too much this in effect was also causing my car to stall out when coming down to idle as the ecu was still overfueling too compansate for the high boost,so new fuel pump on order and the car will be booked back in at Graham Goode.
Also have too say i was there as mentioned for over four hours and because i took the car away effectifully not fixed although the problem was identified the guys or more Alistar only charged me for 1 hours labour and 1 hours diagnostics time how good was that. this level of service and respect for the customer and his car does,nt happen enough in the car tuning ,service game big thumbs up for Graham Goode.