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Heres the problem...
Drive the car from cold goes really well as the engine warms up power (torque) seems to decrease significantly.
Car has been superchipped with turbo pressure at 14psi complete scorpion exhaust including de cat pipe.
Anybody with any ideas????
I am suspecting the actuator?? or maybe the lambda sensor (or though the ecu light does not come on).
This is getting irriatating!! :mad:
 

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Just to make sure, you do realise that as the car gets hot then the power will decrease as the charge temperature increases ??

Apart from that, do you have any induction kits fitted to the car or is it a plain old GM or replacement panel filter ??

When you say you are suspecting the actuator or lambda sensor - Does the car run variable boost all the time or does it manage to run/hold the boost at fairly consistent levels i.e. when you accelerate, does the boost go to say 14psi, then if you do it again it only goes to 9psi then back to 12psi if you accelerate again ?? (I am hoping you have a boost gauge fitted especially as you are running higher than normal boost :rolleyes: )

If the lambda sensor was dodgy, the ECU light would come one.

Rich
 

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As RDS is probally still asleep I'll try to help.
We were hoping you (Richie) would post and help, Ideal!.

I've been in the car when cold and its very very impressive but as it warms its performance appears to detteriate, we realise charge temperature will increase and performance decrease, but the change is of such amount surely vauxhall never intended it to be like that.
Rob would like to fit water injection but we are hoping to get to the bottom of power problem first.

Boost gauge however.... ...not yet.
I think Rob is going to see if he can borrow one from a local tuner for a bit.

Standard element filter.

As for the ECU light this only appears at high speed and high boost, Rob spoke to someone at superchip and they said its perfectly fine as this happens at over/high boost.

Hope this helps some.
Mike :)
 

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The superchip will allow you to run more boost than was intended i.e 0.8 bar. This is not a bad thing as the C20LET can handle around 16psi tops as a standard engine (better at 14-15 which is 1 bar)

The thing is, the superchip may have stopped the ECU from interfering with the boost in order for it to run this high but it still dont stop the ECU from flashing up (code 113 - boost control out of range) and saying "OI, me boost is too high" :D

There aint gonna be a quick fix, I'm afraid its jus a trial and error but you can help this by doing 2-3 things -

  • 1.Fit a boost gauge to see whats happening to the boost levels. If you need help in fitting this then take a look at Fitting a Boost Gauge to a Cav/Calibra Turbo which is found on CavWeb's forums
  • 2. Get the fault codes read to ensure it is ONLY the boost thats doing it (code 113). You can find a guide and a complete code list here - Guide to engine Fault Codes by AndyK
  • Post the problem on the CavWeb Forums as there are a few ppl there with years of C20LET experience that can help LOTS..... try using the "FAO: Dunk, Russ or AndyK" as the subject field there :D

Are there ANY other symptoms thats happening while this is going on ?? Also, we talking just a plain simple decrease in power or is it kangarooing or mis-firing or anythig else ??


Rich

[ 15-07-2001: Message edited by: Richie ]
 

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Forgot to say the ECU light doesn't stay on only comes on for a moment at high speed usually.

Mike.

What about cold to hot??
 

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Oh and a bleed valve in place of electronic thingy.
 

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Rob you online still?

Andy K, whos "pissing about" with a gauge,
He's only had it a month or so!

Mike,
 

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The bleed valve should be adjusted so that the ECU light does not come on when running higher than normal boost. It works by filtering off some of the boost pressure before it gets to the ECU which is measuring it. The ECU then thinks its running lower than it is and the light stays off Superchip should have told you this as they fit it to nearly all of their chipped C20LET's

Thats why its important for you to fit a boost gauge as its all too easy to wind the bleed valve up till you dont know what its doing then BOOM!! :eek:

I think you need to get the codes read firstly as they may point to the fault directly and save a lot of hassle. See, when the ECU light comes on, the car goes into "limp home" mode and runs the emergency map of the ECu so that you can still drive but there is a SEVERE loss of power. Its only meant to allow you to drive it to the nearest garage/dealer to get repaired.

Codes are REALLY easy to do. Follow the guide on the 5th post here and see what it brings up. Codes are flashed as follows btw -
  • flash flash...gap...flash = code 21
  • flash....gap flash flash flash = code 113

As it says in the guide, the 12 code (flash, gap, flash, flash) is shown on the ECU dash light 3 times and then the 1st error code 3 times then code 12 (marker)3 times then 2nd error codes then 12 3 times etc etc.

The codes loop round till you disconnect the wire from the diags plug
 

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Are you booting the car from cold? Not wise.

If the power decreases ONLY when the ENGINE warms up, then it is more likely to be the air temp sensor (on the inlet manifold) or the coolant temp sensor (just below the thermostat). The ecu adjusts the mixture as the engine temperature rises. Maybe another can of worms to open here though - are you sure your fueling is up to the job? The mixture will be rich until the engine is up to operating temp. Maybe it's too lean when it gets up to temp.

The guys are right though, you will notice a decrease in performance on hot days, more with each subsequent heavy application of boost, particularly if you don't have any intake charge cooling.

Need to make sure you are not confusing engine temperature with ambient air temperature - the first doesn't affect power (if it's inside normal parameters and all your ecu sensors are reading it correctly!), but the second does, even on NA cars, and even more so on turbos.

Good try about the filter Rich, could've been sucking in hot air from the engine bay if there was a cone on it. ;)

Water injection is worthwhile and the basic kits are easy to fit. Very useful for higher boost engines to help control detonation.

Cheers
Russ
 

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Russ said:
Are you booting the car from cold? Not wise.

If the power decreases ONLY when the ENGINE warms up, then it is more likely to be the air temp sensor (on the inlet manifold) or the coolant temp sensor (just below the thermostat). The ecu adjusts the mixture as the engine temperature rises. Maybe another can of worms to open here though - are you sure your fueling is up to the job? The mixture will be rich until the engine is up to operating temp. Maybe it's too lean when it gets up to temp.



Cheers
Russ
Mine is the opposite way around when the car is cold it runs like a bag of nails but when it gets up to normal operating tempreture then it runns fine
 

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HI,

I HAD THE SAME PROBLEM WHEN COLD, BUT RUN GREAT WHEN WARM.AS I DIDN'T BOOT IT WHEN IT WAS COLD I DIDN'T THINK IT MATTERED UNTIL ONE DAY IT STARTED POPING AND BANGING.IT TURNED OUT TO BE THE AIRFLOW METER,NOW IT RUNS GREAT WARM OR COLD.


:D

HARKY.
 
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