boost lag and fuel economy question

[hunker7]

Definately running on all 5, I drove from London to Leeds in February on 4

I will have a look tomorrow for timing mark through the little window.

[hunker7]

Not surprising weather is complete pile of ****. I did pull the plugs out;



I unplugged N75 and didn't see any difference either. First one is flooring it in 6th;





Fuel consumption was 23mpg average speed was about 50mph

[hunker7]

When you say crank do you mean the front pulley?



Its a 0 as Newsh picture. Are you looking in the correct hole?

Is the cam timing in the head correct? Two O on the inside of the cam gears should be level with the top of the head and point at each other.

MPG and performance sound way off, its no economy engine but should get 30 on cruise, drive ability about town is one of its perks.

Timing mark is on the big drive belt pulley that bolts together with the small timing belt pulley.

I will take rocker cover off and have a look, but I haven't removed the chain.

About the 0 mark, I'm sure I am looking at the right place.

[UrS4boy]

I unplugged N75 and didn't see any difference either. First one is flooring it in 6th

If that is true, then the ECU is not seeing the mechanical boost/vacuum signal at the MAP sensor.

Perhaps the hose is off at the Moisture Trap or your MAP sensor is Fubar.

[hunker7]

If that is true, then the ECU is not seeing the mechanical boost/vacuum signal at the MAP sensor.

Perhaps the hose is off at the Moisture Trap or your MAP sensor is Fubar.

I meant it didn't change anything regarding running. It limited boost at 1.4bar and regarding moisture trap, I have new clips on all vacuum hoses

[UrS4boy]

I meant it didn't change anything regarding running. It limited boost at 1.4bar and regarding moisture trap, I have new clips on all vacuum hoses

Sorry but you need a second driver opinion. Is there no one near you with a properly running AAN-powered UrS4 or UrS6 that you can drive and/or they can drive your's?

Flooring the car in 6th is not a good boost or acceleration test if the RPMs are way down, e.g. less than 2500. That is NOT how you drive these cars.

[Error404]

I still believe this is a mechanical issue not ECU related. The ECU is clearly requesting boost and you are achieving it, but the turbo seems unable to deliver it at the rpm you would usually expect it at. The would suggest to me a restriction in the intake / exhaust.
If the ECU detected timing was incorrect I would think it would not request boost.

[hunker7]

I am 100% sure there isn't blockage in manifolds. I will check all the nuts and bolts if they're tightened as downpipe was off if that's all fine I'll look into exhaust and see if that's blocked.

[andy10v]

I still believe this is a mechanical issue not ECU related. The ECU is clearly requesting boost and you are achieving it, but the turbo seems unable to deliver it at the rpm you would usually expect it at. The would suggest to me a restriction in the intake / exhaust.
If the ECU detected timing was incorrect I would think it would not request boost.

Like Jase11n's S2 with the blocked cats? Down on power, poor economy and a prolonged diagnosis.

[hunker7]

Is there a way to check if exhaust is blocked? I've been planning on getting a decat made up but not just yet.

[andy10v]

You could hook a boost pressure gauge up to test pipe in the downpipe, you would need a "normal" reference though.

Jas11n removed his cats to check.

[mike74]

Unscrew and remove lambda sensor then take it for a quick drive. If the exhaust is blocked then that should help it a bit

[hunker7]

Unscrew and remove lambda sensor then take it for a quick drive. If the exhaust is blocked then that should help it a bit

I think there is a bolt on downpipe that I could take out, remember doing this on my V6 to check blocked exhaust .

I'll check that out actually.

[Henkjan]

how is the air flow meter?

[hunker7]

Got a refurbished one, it was much better.