Wentworth lumpy at start and heavy fuel consumption

[Jeevess]

Hi
Well my old girl, owned for 10 years has been back on the road for 2 months. She's had new head gasket, cat, distributer, leads, radiator, plugs, water pump..
She is running lumpy at tick over and seems to be using a lot of fuel. Can't seem to see any air leaks or fuel leaks.
She runs smooth when hot but does seem to lack the power I seem to remember. (off road for 18 months)
There is a bit of a rattle when coming from the turbo when it disengages as such..
Any ideas where to start?
Much appreciated

[aardvarkash10]

head gasket + odd idle + lack of power + fuel use increase = cam timing error as a first guess.

Outside that it is a process of following a logical test sequence. Helps to have access to a bit of test equipment and the relevant Green Book.

Is it the B200 turbo engine?

[Laird Scooby]

In addition to Ash's excellent suggestion, it's also worth checking/replacing the Coolant Temperature Sensor (CTS) for the ECU - not the gauge sensor which is a different animal.

If the turbo is rattling, that might bear further investigation but usually gives a lot of white smoke from the exhaust if it is on its last legs.
More likely to be a loose heatshield or something.

Please tell me when the head was skimmed and you refitted the sensors you didn't use PTFE tape to prevent leaks? That also prevents the CTS earthing correctly, resulting in the ECU thinking the sensor is faulty and goes to preset values so the engine can run but won't be great on performance or economy - this is known as Limp Mode. If you used PTFE tape on the sensors this is likely the cause of your problem.

[Jeevess]

[QUOTE=aardvarkash10;2465968]head gasket + odd idle + lack of power + fuel use increase = cam timing error as a first guess.

Outside that it is a process of following a logical test sequence. Helps to have access to a bit of test equipment and the relevant Green Book.

Is it the B200 turbo engine?[/QUOTE
Yes B200FT.. Thanks for your advice

[TheLeeds]

All of the above makes sense.
Only thing I can add is, have you reconnected the throttle position sensor ? I forgot once after working on the car, and it ran like it was on lager instead of petrol.

[Forrest]

If the head gasket has previously failed there is a good chance the o2 sensor in the exhaust near the turbo has been damaged by the hot water vapour in the exhaust. This could be causing the over-fuelling.

[Laird Scooby]

Originally Posted by Forrest

If the head gasket has previously failed there is a good chance the o2 sensor in the exhaust near the turbo has been damaged by the hot water vapour in the exhaust. This could be causing the over-fuelling.

Good shout but the way i read the original post, it's lumpy when cold and fine when hot? This would suggest another problem like Ash suggested, timing most likely especially as the Lambda sensor isn't used to control the fueling until it's heated up and so has the engine. Until that point, it runs open loop sois running lumpy on open loop but fine on closed loop, suggesting the Lambda sensor is fine.

Could be the MAF is clogged with gunge of some description or possibly the intercooler.