Td5 no power

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I thought that if it ran the same with or without the MAF connected, that it suggested a duff MAF as the ECU was running with it's defaults? o_O
 
leeby7 said:
cant think what else it could be? when i opened the air box there was no air filter in it at all for some reason
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Can be a clogged CAT if it still has it or it ran much without air filter and sucked in much dust the compression can be low as well due to worn piston rings... i'm wondering how well it was serviced though if you just realised it doesnt have a filter:rolleyes:

go somewhere where the noise is not an issue, undo the downpipe from the turbo and make a drive test ...if it will have good power this way fit e de-CAT downpipe
 
That pipe you remove from wastegate and put on the pipe that goes to intercooler? do you have to put a feesh piece of pipe on as it looks too short? thought someone mentioned you just pull it off and place on intercooler pipe?
 
If you want to bypass the modulator you have to take the pipe which runs from intercooler to the bottom port of it and connect it to the actuator valve but i doubt it's that cos the symptom you described doesnt look like overboost at all
 
overboost, it would be ''agressive" with good power up to max 3000 rpm then cut fuelling for overboost protection then regain power after few seconds when the rpm drops and so on... better concentrate on that flow thing in the exhaust first
 
MAP sensor can also cause gutlessness. Also, check that your Ambient Pressure sensor is connected correctly too. Had this a while ago with another TD5.
 
leeby7 said:
Hi simon where is ambient pressure sensor located? is it on the air box
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Yeah it is. Often I've found its the MAP sensor. If you measure the output, idle should be about 2v if I remember corectly. Full load was about 4.3v (1.2bar) I think. Don't count me on those figures, but its a start to the diagnosis.
 
Simon098 said:
Yeah it is. Often I've found its the MAP sensor. If you measure the output, idle should be about 2v if I remember corectly. Full load was about 4.3v (1.2bar) I think. Don't count me on those figures, but its a start to the diagnosis.
Click to expand...
There seems to be an element of confusion here. The MAP sensor is mounted on the inlet manifold, that's the "Manifold Absolute Pressure/inlet air temperature sensor.
The MAF is built into the air pipework between the air filter and the turbo. It's the Mass Air Flow sensor.
The sensor to which I think you are referring is the Ambient Air Pressure (AAP) sensor which is mounted in the side of the air filter box.
 
brian47 said:
There seems to be an element of confusion here. The MAP sensor is mounted on the inlet manifold, that's the "Manifold Absolute Pressure/inlet air temperature sensor.
The MAF is built into the air pipework between the air filter and the turbo. It's the Mass Air Flow sensor.
The sensor to which I think you are referring is the Ambient Air Pressure (AAP) sensor which is mounted in the side of the air filter box.
Click to expand...
I'm talking about the MAP sensor and the AAP. If the AAP is disconnected, the ECU controls the pressure at 0.9 bar.

If the MAP sensor reads wrong, the fueling calcs go all funny and it feels like its gutless. Alot of more modern vehicles seem to use the MAF for fuel calcs, but this one seems to use the MAP.

Heck the ECU could think its at 1.2bar already when in fact its only at 0.2 bar.
 
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Actually the default for AAP complete failure is boost limited to 1 bar though the OP didnt report black smoke and for both AAP or MAP failure in most cases black smoke is present under hard throttle cos when they start to fail the readings are going lower not higher so the ECU compensates for the presumed lack of boost (based on the low reading) with more fuel... though IMO these things can't be properly diagnosed without tester or going the rudimentary way by replacing them with new or known good ones and hoping this would fix things
 
the ambient pressure sensor wires were damaged! repaired and is alot better, and eplaced the air filter, one thing i did notice is that there is 2 plugs unplugged drivers side close to bulkhead? i am presuming these were for the egr valve which has been removed
 
Yes, Personally I noticed no real difference. That I could quantify. Others say how amazing the change was and that the earth moved for them....who knows.

Except it sounded better. ...........................:p:p

Cheers
 
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