52 replies to this topic

[mbes2]

Suspect vacuum leak.... somewhere.... Anyone any good with ECU output to help spot anything..

 

Symptoms - hard throttle anything under 3k it bogs down, doesn't do it under slow smooth throttle.

 

Anything over 3k its fine.

 

The only error code that comes up a few times now is P0170, which points to a leak causing wrong mix of fuel/air.

 

The P0170  "Fuel Trim Malfunction (Bank 1)" 

 

I've replaced the following:

 

Coil pack

MAF 

Intake sensor

lambda sensors(both)

Checked all pipe work/clips for splits, nothing found.

Plugs 

Fuel pump

 

 

[attachment=26370:ECU output Capture.txt]

[fezzasus]

fuel pressure regulator?

[siztenboots]

short fuel trim values are going to -25% which is why you get the error. there must be a air leak somewhere is the exhaust gasket good? any sign of sooting around cylinder 3 or 4? are exhaust studs all there and tight?

[Nev]

Check your inlet manifold studs are tight. Check TB is tight and green rubber gasket is good.

Edited by Nev, 19 July 2015 - 07:55 AM.

[mbes2]

Couldn't spot anything like above. Will remove heat shields and check bolts in the week. I can see the -25 now, good understanding Thanks guys

[mbes2]

Not sure how good the torque app is for boost.. shows 32psi...lol

[siztenboots]

Correct that's the over boost

[siztenboots]

sorted it yet? are you working from home tuesday?

[mbes2]

sorted it yet? are you working from home tuesday?

Yep, shall I put the kettle on ?

[Bargi]

Could it possibly be your air filter colapsing or blocked? Saw a turdo with similar symptoms and turned out the filter was completly waterlogged from hitting a big puddle on the trip.

[mbes2]

Watch "Finding Engine Vacuum Leaks With A Cigar" on YouTube - https://youtu.be/zMok2y05jNE

[mtt88]

Have you tried pulling fuse 8 out? I had something similar to this on my vxt and was down on power. Think it resets the fuel trim and ecu learns it all again?! Worth a try?

[mbes2]

Have you tried pulling fuse 8 out? I had something similar to this on my vxt and was down on power. Think it resets the fuel trim and ecu learns it all again?! Worth a try?

Good thinking, will give that a try tonight, Deffo something odd going on

[Nev]

Hopefully you will receive the bung tomorrow. Do you have a compressor and 1/4" pressure line to plug it into ?

Edited by Nev, 22 July 2015 - 05:07 PM.

[Nev]

Have you given the turbo a good few whacks with a hammer to check the wastegate isn't stuck open? Alternatively, try pulling on the wastegate spring and see if it will move (if you have enough access room to actually lever the thing).

Edited by Nev, 22 July 2015 - 05:09 PM.

[mbes2]

Fuse 8 removed.. will re fit in the morning.. then test drive

[mtt88]

Think I left mine out for about half an hour then replaced it and it made an electronic sound after refitting.

[siztenboots]

it will clear any fault codes and zero the fuel trims, but they will soon adjust back if there is still an air leak between the MAF and the lambda sensor.

[mbes2]

it will clear any fault codes and zero the fuel trims, but they will soon adjust back if there is still an air leak between the MAF and the lambda sensor.

 

Symptoms the same, if anything more noticeable now 

 

Device Time Fuel Trim Bank 1 Long Term(%) [color=#ff0000;]Engine RPM(rpm)[/color] Fuel Trim Bank 1 Short Term(%) Intake Air Temperature(°C) Speed (OBD)(mph) Turbo Boost & Vacuum Gauge(psi)

43:36.2 -0.78125 [color=#ff0000;]1402.25[/color]  -25 26 0 -10.49400997

43:37.2 -0.78125 1454.5    -25 26 0 -8.05953979

46:41.2 -0.78125 3654.25  -25 27 34.17541504 -2.1222434

49:58.2 -2.34375 2881.25  -24.21875 27 26.71896172 -6.42941284

46:46.2 -1.5625   2834.25  -21.875 27 39.14638519 -4.32305241

46:58.2 -1.5625   3007.75  -21.875 26 42.25324249 -8.73950768

46:59.2 -1.5625   3006.25  -21.875 26 42.25324249 -8.76626015

47:00.2 -1.5625   [color=#ff0000;]3001 [/color]     -21.875 26 42.25324249 -9.21500492

[Nev]

Sounds to me like it may be some sort of lambda issue. Have your double checked the contacts? Have you go spares to swap out the sensors themselves?