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  #11  
Old 01-12-2017, 12:22 PM
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Since the boost is ok, it has to be fuel metering. And that's going to be:

1) MAFS
2) SCV
3) Injectors
4) Fuel Rail Pressure Sensor

The MAFS is highly suspect. Here's a trick to check if it's operating properly.

I've noticed that at 80km/h or more (with a snorkel - you might need to go a little faster, like 100km/h) the MAFS reads the same as the ambient temperature. If you don't have the ambient sensor, just a normal thermometer will do (in shade). Grab your Torque app and load up the Intake Air Temperature. Go for a drive and check the temp.

If the temp is close to the measured outside temp then your MAFS is likely fine. I suspect it may not be. The MAFS uses the voltage difference across a hot wire to determine how much air is flowing. As a wire heats up, its resistance increases and the voltage difference across the wire becomes greater. As air flows over the wire, it is cooled, lowering the resistance. Thus it is possible to measure the amount of air flowing past - as long as you know the temperature of the air.

That measurement is crucial. If there's dirt on the MAFS, the wire may show less resistance, which (as a sensor reading) indicates a greater cooling effect which is usually the result of more air. If the ECU believes there's more air moving in, it will increase the fuelling appropriately.

The answer to that is to clean the MAFS. Precautions shouldn't be taken lightly. Even if you can see the muck inside, do NOT EVER touch it. Just keep spraying more contact cleaner in the hole. I just found a thread on this that I wrote here. Pictures included.

Please let us know how it goes! I'm obviously assuming it's not going to be SCV/injectors or FRPS. This last one has been a sore point a couple of times, and may just be dirty contacts, but if you monitor fuel rail pressure in Torque as you're driving and you don't spot any spikes/dropouts while moving (try choosing a graph mode to see this) then the electrical connection is not suspect.
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  #12  
Old 02-12-2017, 11:56 PM
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replaced the air filter and cleaned the MAF, then thought, nah, that's not going to fix it. So snooped around , and what did i find, the usual culprit.
Car is back to normal!

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  #13  
Old 03-12-2017, 04:16 AM
jonney jonney is offline
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well hows that. i can see why those hoses broke. bad design in bends.
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  #14  
Old 03-12-2017, 04:22 AM
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2 or 3cm's longer would have made all the difference!
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  #15  
Old 03-12-2017, 04:50 AM
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yes. it just looks like the tubing has too much bend in them.
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  #16  
Old 03-12-2017, 07:50 PM
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The tubing is like that so you can get the hose onto the tube. It's nice that it's at the top of the engine and not down near the vac pump (above the fuel pump, below the intake manifold). The hoses look like they weren't quite long enough. Your brakes must have been suffering too!

It's surprising that it boosted properly, but obviously not properly enough! I think I'll make it a mission of mine to replace that hosing every couple of years just to be on the safe side.
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  #17  
Old 04-12-2017, 02:57 AM
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yeah, was strange, as understandably, there was zero boost under normal driving, but if i booted it, boost reading went up as afar as 18psi. now there is always some boost, even at idle, and shoots up to 21psi.
funny thing was people were asking me if iv'e had an exhaust fitted, as the car was much louder, and i couldn't hear any induction noise through the snorkel anymore. makes sense now, as the turbo vanes would have been open all the time.
Also, turning the engine off was more abrupt when it came to a halt, now it's smooth again!
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