Carbon Canister removed, tick over crap

[Rustynuts 0]

Having decided to do the carbon canister removal on my G60, all relevant hoses blocked off. Now idle seems a little rough and car has a tendency to to stall coming up to junctions (not good when your ignition switch is dicky!!) I have had a play with the idle screw to see i that makes a difference, strangely it makes no difference what so ever.

 

Any ideas?

[h100vw 0]

Idle adjustments MUST be made with the BTS disconnected or the ECU ignores what you do.

My guess is there is a pipe that needs blocking off somewhere.

 

Gavin

[Rustynuts 0]

All pipes are blocked off, checked for leaks and all seems ok. Its a strange one, but thanks for the advice on the blue temp sensor, i tried disconnecting the blue sensor but the engine died, which is a little odd i thought but that could be because the idle is too low

[VR6 0]

Shouldn't block the petrol tank breather .....

[h100vw 0]

All pipes are blocked off, checked for leaks and all seems ok. Its a strange one, but thanks for the advice on the blue temp sensor, i tried disconnecting the blue sensor but the engine died, which is a little odd i thought but that could be because the idle is too low

 

Sounds like you have the screw in too far. Wind it out and try again. When you disconnect the BTS it sends the ECU into basic setting mode. You get no interference from the ISV. Set the tickover to 900 ish then reconnect the sensor.

Good point Tom, you will create a vacuum if the breather is blocked.

 

Gavin

[Andy Brookes 0]

Toms correct, need to vent the tank breather pipe to the inner wing.

[Rustynuts 0]

I have vented the tank, into the back of the airbox, when i meant blocked pipes, I meant all the ones i was supposed to.

 

Anyway, thanks to G-man (Darren) he diagnosed the problem over the phone, i had put the ECU pipe on the wrong connector on the back of the throttle body. Interestingly the car absolutely flew like that, probably due to the ECU pumping in too much fuel. Might swap them back over for next month at the pod to see if i get better times.

[steveo29 0]

what did you use to block of the vac pipes?? id like mine to look neat n tidy

[Dubcharged 0]

Interestingly the car absolutely flew like that, probably due to the ECU pumping in too much fuel. Might swap them back over for next month at the pod to see if i get better times.

 

I wouldn't recommend you try that one! With the ecu hose on the wrong side of the butterfly valve, the ecu always sees zero boost and so fuels as if it was zero boost. If you floor it and get positive pressure (boost) into the engine, it will become incredibly lean since fuelling will be for zero boost!

:cry:

[Rustynuts 0]

I don't understand that, because it smells like a petrol station when they are on the wrong way round. Surely if the ecu hose is on the wrong side of the butterfly valves the ECU will see permenant boost all of the time?

 

Anyway, did try it at the pod, made no difference to the times and all i really managed to do was burn my hand on the rather hot inlet manifold.

[Dubcharged 0]

When the hose is on the wrong side of the bypass valve, at idle it will see zero boost and zero vac so the ecu will over fuel (as if you are driving with partial throttle and boost gauge moves from vac to zero). When you floor it, the bypass butterfly is closed and so that side of the system will not see any boost built up in the inlet manifold, so your ecu will still think its off boost and wont fuel properly whilst your engine is seeing boost and getting VERY lean. Hence your hot manifold. You're lucky you didnt do major damage.

 

 

Basically you will overfuel when under vac, and under fuel under boost cos the ecu wil always see zero net pressure.

[Rustynuts 0]

Ah, but the hose that connects to the ecu is never on the wrong side of the bypass valve. It can be the wrong side of the main throttle butterflies. Now in its normal position i can see that the ECU gets a reading depending on how open the butterflies are. If it is the other side surely it will read boost even if the bypass valve is open (ie when the throttle is closed) or closed (when the throttle is open. In effect there is always boost running across the pipe.

 

I don't think at any point my car was running lean, otherwise it would have been very noticeable on my times at the pod.

 

Now i am not trying to be clever here, if something else is happening you might have to explain it in layman terms.

[stevemac 0]

what did you use to block of the vac pipes?? id like mine to look neat n tidy

Use "diesel injector blanking plugs". They're little rubber pipes about 3/4 inch long - blocked at one end. They fit very tightly over the vacuum outlets that you need to block off.

 

Available from most car/van parts outlets & motor factors.