250 actuator holding too much pressure

Discussion in 'Mechanical - Engine, Gearbox, Exhaust etc' started by odinson, Apr 23, 2015.

  1. So was hoping to collect my new (to me) rs250 from ktec on Saturday and being a good 6 hour round trip it's not exactly down the road. So I was delighted to hear that the car will not be ready due to the forge actuator holding too much pressure? The cars got front mount intercooler, decat downpipe, miltek cat back and was having updated map fitted by them before collection. Surely it's just the spring in the actuator? Will this take 2 days to resolve? Been waiting for a week for new exhaust to arrive so couldn't collect the car last week and bow may have to wait another week to collect it.

    Was hoping to get some decent days driving out of her this weekend too
    Big Uno likes this.
  2. Like I told you before, Ktec have a mixed reputation. Some people won't go near them...

    Hope all is well for you though buddy.
    Big Uno likes this.
  3. Something don't sound right there.
    How did the previous owner drive it if it was over boosting?
  4. Well the have had the car on the dyno for an updated map due to the downpipe being fitted so I'm assuming it's to do with the new map etc
  5. That sounds suspicious to me. Have you a refundable deposit ?
    Big Uno likes this.
  6. It's rather impossible to overboost the RS250 with the actuator. The 250RS uses the throttle valve to regulate boost pressure as well. I've tested this with all the springs that come with the Forge actuator, I simply can't get it to produce any more boost than the mapping permits into the intake manifold.

    So I'd say it is down to the mapping being flimsy, or the actuator is almost stuck, resulting in an extreme amount of pressure in the intake piping system (but not necessarily in the intake manifold due to throttle valve regulation) which may cause limp mode.
  7. Not on the parts I've paid to have fitted as they needed to be done before the mapping session
  8. Maybe a faulty actuator
  9. Or dodgy mapping as tymen says...... They still have Andy Cutler doing their maps :eek:
  10. Pretty sure it throws it into limp mode if it over boosts so impossible to dive with that fault anyway .
  11. Yer they think it's a faulty actuator as the cars going in to limp mode. They are throwing an oem actuator on the car so see what's what
  12. Ovy


    THIS!!! Until recently I was wrong about this scenario so did abit of homework on it IMO the actuator would have to be faulty or it would have to be the map. Also they could just be feeding you a lot of horse as the cars simply not ready?
    Just for your info my car came from Ktec It was overpriced but got it on a trade deal as it was the closest to the spec I was after at the time and it was purchased standard. The Car has been ok only a small gearbox leak not picked up by them. All my work n mods done elsewhere though.
  13. well I'll find out what it's like when I get it I suppose.
  14. Got a call the cars fine now with standard actuator.

    Made 291bhp 320lbs torque With turbo back exhaust, ktec front mount intercooler, panel filter and map. David did say the dyno room was pretty hot today. Not sure if they are good or bad figures
  15. Not great figures.

    I wouldn't let my own car go anywhere other than RSTuning personally.
  16. Ovy


    The torque is in and around the right area but bhp is a bit low considering the mods. The bhp is calculated via the torque and that figure isn't too bad regardless of it being abit warm.
  17. Well I pick the car up Saturday so will see how she is, nothing stopping me taking a trip up to Leeds for a mapping session..
  18. a couple of days ago on a spirited drive, I noticed that the car seemed low on power right from the get-go. Boost gauge (OBDII) showed 2,3 bar (1 [email protected], so showing data from the MAP in the intake pipe, I suppose), but sometimes it would go to 2,5 and once it went all the way to 2,9.

    Car (RS250) is mapped to 315'ish hp, so 2,5 would be a reasonable max value, I suppose (AFAIK, RS265 is about 1,3-1,4), but 2,9 sounds way too high - Am I likely to be looking at a faulty actuator, or maybe a sticky waste gate? (first I thought I maybe had a leak, but 2,9 counts against it)

  19. Could be a faulty map sensor
    Big Uno likes this.
  20. I had a stuck actuator and the car never never went into limp mode. Renault couldnt find a fault and RS tuning in SA found it been stuck. Drove the car for 10 000km and never gave error codes

    Sent from my BLA-L09 using Tapatalk
  21. The ECU would set a code if the two MAPs didn't read similarly at WOT, I'd think..

    I suppose it could also be the recirc not closing properly..

    Is the OE actuator available from anywhere? It doesn't seem to have a Renault part number. If not, a forge or boost island replacement unit could be an option..
  22. As far as i know you buy it complete with the turbo from Renault. Thats why people go with the forge ones if they have issues

    Sent from my BLA-L09 using Tapatalk
  23. By the way, should I be able to move the actuator arm by hand/using pliers, when it is in working order? It doesn't seem to move when I try that..
  24. Big Uno

    Big Uno RSM Trader

    Is the forge actuator new (something you paid for?) Or was it already on the car?

    The diaphram inside (im assuming the forge ones have one?) May be damaged. Presumably the actuator is the fault if refitting the OE one has solved the problem.

    In the case that it was already fitted, it was probably why the car was sold to them in the first place, and shows how well it was tested on sale :tearsofjoy:

    Also did they mention if that power is measured at the wheels or flywheel? Presumably flywheel?
    I would say injectors are probably the limiting factor for the power you have. Ill guess they didnt mention the duty on them making 290hp? Probably high and near their limit so may be worth looking at some 630s later :blush:

    Anyway I hope everything goes well with it for you!
  25. Big Uno

    Big Uno RSM Trader

    There is no way a 2litre will produce enough exhaust flow to spool a turbo to make 1 bar on idle, it is most definitely an electrical fault as Ian said probably map sensors. How does it idle? Are the revs sitting high? May be leak at manifold but unlikely. It is highly unlikely to be wastegate or actuator related IMO.

    Also I would not suggest driving it as your AFR will be all wrong which probably explains the loss in power, however when you did drive it did you find the turbo seems to be spooling as normal?
  26. That is normal.Map sensor is reading absolute preasure.that is why it is showing 1000 mbar on idle.
  27. Big Uno

    Big Uno RSM Trader

    Good point. 1 bar is atmosphere.

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