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Discussion Starter #1
Hi All

I'm getting an intermittent but severe misfire on medium to high acceleration.

It can also go into limp mode with the flashing red throttle warning light.

I've checked the wiring loom/ aircon pipe fault and although it has rubbed quite badly no wires are broken.

The codes that are thrown up are confusing.

P0234 Turbo overboost and P0299 Turbo Underboost.

My knowledge on turbos is limited but I notice that there is a servo on the turbo with an arm attached going into the turbo. Does this control the wastegate and could it be faulty?

There are no other codes.

Any advise would be greatfully received.

Regards

Doug L
 

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Hi Doug,

It could be the actuator you suggest but think you have to eliminate other things first.
If you note the actuator linkage while someone else turns the ignition on you should see the actuator linkage move by a few degrees and then settle back again. You could make sure the external linkages you can get at arnt seized.

You could check for air leaks on the big hoses on the intercooler at the front of the car, i suppose these could in theory be flexing about and sometimes leak and re-seal making it difficult for the pressure to be controlled acuratley. But the most likely item would be a faulty pressure sensor or faulty connection/ wiring on the pressure sensor. You could do with being able to look at the live data to see if there are any strange spikes from the pressure sensor.

Many cheapish code readers will display live data, including the Torquepro app for an Android phone or tablet.

EDIT
Some members have found a leak on the turbo outlet pipe due to a missing "O" ring. On the metal pipe joint at the top of engine just after the turbo, running the length of the engine.

jack
 

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Discussion Starter #3
Many thanks Jack.
My little code reader will give live data and I'll try it on the way home tonight. I have access to a much better reader/diagnostic box which I'll get hold of later.
The actuator arm actually feels loose with a bit of wear in it.
I'll check the outlet pipe for leaks as well as the other connections.
I have a Drake2 box on it which I'll take off just to eliminate it.
Regards Doug
 

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Discussion Starter #5
Hi Jack

Update: I used another code reader and it picked up P0046 (Boost control circuit performance). It can't erase it so I might now have a solid fault.

The actuator doesn't move with the ignition turn on.
Please can you give me guidance as to the location of the pressure sensor.
Rgds Doug
 

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Hi Jack

Update: I used another code reader and it picked up P0046 (Boost control circuit performance). It can't erase it so I might now have a solid fault.

The actuator doesn't move with the ignition turn on.
Please can you give me guidance as to the location of the pressure sensor.
Rgds Doug
Hi Doug,

The boost pressure is determined by 2 sensors. One in the air filter housing and one at the front left of the engine when looking from the front.

BUT: It appears you dont need to bother with that because P0046 points you in a better direction.
P0046 is the detection of an electrical fault on the actuator for the Turbo. Either shorts to chassis or shorts the the supply , or possible actuator fault. So you either have a fault on wiring that you haven't yet found or probably the actuator is faulty. Also proven because the actuator didnt move when ignition switched on.

You need to check the wiring and actuator. Its not easy to prove the actuator itself cos it operates with a Pulse Width Modulation signal to drive it, but you can at least check for the supply voltage and the continuity of the actuator to see if you can detect a fault.

The actuators do fail sometimes though and are only supplied as part of the Turbo (Bloody Expensive). You can though buy them second hand or reconditioned sometimes though.
I'm not sure I believe the "reconditioned" bit though. Probably just a used one thats been checked.


Jack
 

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Discussion Starter #7
Thank you Jack
Actuators on ebay are about £180 exchange. There are alternatives on the interweb as well. Input voltage should be easy to check. Tracing the wiring back may take some time. Rgds Doug
 

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Thank you Jack
Actuators on ebay are about £180 exchange. There are alternatives on the interweb as well. Input voltage should be easy to check. Tracing the wiring back may take some time. Rgds Doug
Yes:
Pin 1: 5V permanent supply
Pin 2: Chassis
Pin 4: PWM signal. Could measure with an AC voltmeter but ideally would need an oscilloscope.


Jack
 

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Your too kind !!!! lol
Yes retired now Paul.

Was a TV Engineer on leaving schools and got my electronics from there.

Worked as an Instrument Technician at a big 2000MW Power Station before progressing to Maintenance Supervisor looking after all the Stations: Instrumentation, Electrical and Mechanical before retiring.

Did a lot of hands on fault finding and maintenance work on Power stations including Instruments, Electrical, Pneumatics, Hydraulics, Mechanical.

No qualifications on Cars at all but got a good grounding in all sorts of mechanical and Control systems.

Regarding the P0046 code, it doesn't really take a lot of deciding what can cause the problem, its clearly identified in the workshop manual. The only possible thing that can bring it up is an electrical fault. It cannot be brought by just running conditions or Boost Pressure being abnormal. P0046 only checks for voltages being abnormal. (That's assuming Chrysler Manual is correct. Lol !!!! I dont really trust Chryslers info.)

Jack
 

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Discussion Starter #12
UPDATE

Changed the turbo actuator today and all appears OK. I've done some full throttle acceleration through the gears with no hesitation or cut out.

Many thanks for your help Jack.

As an aside, I had to do a 100 mile round trip yesterday, travelling at 70 (2000 rpm) with minimal acceleration. It returned 46.3 mpg!!

Regards Doug L
 

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UPDATE

Changed the turbo actuator today and all appears OK. I've done some full throttle acceleration through the gears with no hesitation or cut out.

Many thanks for your help Jack.

As an aside, I had to do a 100 mile round trip yesterday, travelling at 70 (2000 rpm) with minimal acceleration. It returned 46.3 mpg!!

Regards Doug L
Result !

Re fuel consumption. Sounds too good to be true, i dont get anywhere near that. I assume thats from EVIC reading though and they are often inaccurate.

I always calculate mine manually.



jack
 

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Actuator

UPDATE

Changed the turbo actuator today and all appears OK. I've done some full throttle acceleration through the gears with no hesitation or cut out.

Many thanks for your help Jack.

As an aside, I had to do a 100 mile round trip yesterday, travelling at 70 (2000 rpm) with minimal acceleration. It returned 46.3 mpg!!

Regards Doug L
Hi Doug
Do you have a link for the Actuator as I have the exact same problem.

Many Thanks.
 
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