11 replies to this topic

[JG]

This seems to have been posted on here about three times in the past but none have been updated since. Benw if you're reading this , you were one of them. So i'm getting this code combined with rich running. Car is booked in to be fixed but if i always like to have a go first. So if anyone has any experience of this, please let me know. Thanks, James.

[Zoobeef]

This seems to have been posted on here about three times in the past but none have been updated since.

Benw if you're reading this , you were one of them.

So i'm getting this code combined with rich running. Car is booked in to be fixed but if i always like to have a go first. So if anyone has any experience of this, please let me know.

Thanks,
James.

Computer says

Fault: Fuel system lean mixture during acceleration,

Possible causes: Fuel filter, fuel pressure low, MAF sensor, TP sensor, HO2S, injectors


Dont know if thats any help

[NickB787]

I wouldn't be supprised to see more of these. Me thinks OEM fuel pumps are getting old.

[Winstar]

if the fault code says it's running lean but the car is actually running rich then won't it be the pre-cat lambda sensor? or possibly an air leak pre sensor, cracked manifold? fuel pump would be fault code coupled with running lean wouldn't it

Edited by Winstar, 07 July 2009 - 02:34 PM.

[vocky]

I had that error due to a faulty mixture lambda sensor (the one between the cat and manifold)

[Zoobeef]

if the fault code says it's running lean but the car is actually running rich then won't it be the pre-cat lambda sensor? or possibly an air leak pre sensor, cracked manifold?

fuel pump would be fault code coupled with running lean wouldn't it

That sound very sensible to me

[Shamone]

I'm still working on mine I fixed an induction leak on the brake vacuum hose and fitted a new post cat lambda sensor but still get it. I also cleaned the connections on the two main plugs behind the expansion tank and checked out the fuel pump relay with a bench power supply and multimeter. I have now bought a scan gauge so I can clear it easily, although it's still a pain as I'm a perfectionist when it comes to things like this. Courtney did think it was the cold start cycle (mines supercharged) but now after much use recently I realised mine occurs on part throttle when the engine is fully warm. I used Gendans EngineCheckPro to view the freeze frame data and every time I get the fault all the parameters captured are very similar. Calculated Load 25.49 % Coolant Temperature 88. C Short Term Fuel Trim Bank 1 7.81 % Long Term Fuel Trim Bank 1 0. % Intake Manifold Pressure 38 kPa Engine Speed 2265 rpm Vehicle Speed 87 km/h Ignition Timing Advance 16. º Intake Air Temperature 25. ºC Fuel System 1 Status Open Loop (accelerating)

[JG]

that interesting as i have a crappy lamdba sensor. can't remember which one, but i know one of them is not oem.

[vocky]

the cheap sensors are rubbish use NGK lambdas, exactly the same as OEM but cheaper

[JG]

For future reference if anyone gets this code. I replaced the lambdas with vauxhall ones and i can't replicate the fault. Consumption seems to have dropped too. Shall be out driving toay, empting a tank of optimax to see what its like.

Edited by JG, 22 July 2009 - 08:30 AM.

[benw]

Just found this thread while searching for something entirely different but thought I'd add that my P1171 was the result of a cracked exhaust manifold. Whether it was the loss of gases through the manifold or the rich mixture fouling up the lambda sensor that caused the fault code I'm not sure but it may be worth checking both if you get P1171.

[markv]

Just found this thread while searching for something entirely different but thought I'd add that my P1171 was the result of a cracked exhaust manifold. Whether it was the loss of gases through the manifold or the rich mixture fouling up the lambda sensor that caused the fault code I'm not sure but it may be worth checking both if you get P1171.

lean mixture sounds like a logical error code with a cracked manifold. Oxygen is getting in at the manifold, causing the lambda sensor to read a lean mixture. ECU will try to compensate for this, but hasn' t got enough room to fix the leak. So you should get an engine running pretty rich with the ECU logging a lean mixture code..

Mark