Problem with a 2 litre zetec turbo running an Emerald ECU mapped by Dave Walker. on getting the car back home it wouldnt fire up the following day unfortunately it was found to have 2 bent valves. so head sent off new valves fitted, lapped in etc head refitted car starts and tick over no problem sounds sweet. However when revved the car dies down, if we unplug the MAP sensor the engine revs up okay the turbo spools and dump valve opens. it will run but doesnt pull with the MAP plugged in it will run without the MAP but there is no boost. A lot of head scratching has gone on head stripped off everything resealed wiring checked nut same problem exists. Any ideas chaps ? PS petrol use ie excessive

ok so is the waste gate stuck open as you say there is boost but no power? its a process of 1 thing at a time

when reved stationary the dump valve opens and releases to the atmosphere, this is when the MAP sensor is disconected

have you tried another map sensor?

when a map sensor fails most ECUs will run its maximum load value i.e. full boost fuel values/corrections. although this doesnt explain why it runs unplugged??

if you can connect to your emerald, check that the sensors are reading correctly, coolant temp, air temp, TPS and MAP ( + lambda if used)

more than likely to be a sensor fault, or a fault with the wiring.

- colin.

with the map sensor attached it now shows its running lean without it connected it is over fuelling

because you have unplugged it, the ecu will run the map sensors default maximum value, i.e. full boost fueling. hence the richness.

have you managed to connect to the emerald?

woud be interesting to see what the map sensor is reading when plugged in, and obviously see what the other sensors are doing.

- colin.

just run the car for 10 minutes engine up to temp etc connected to data logger all sensors appear to be working okay with values altering when accelerating de celerating . However the graph line for boost is flat signifying no boost any ideas ??

Perhaps start at the start?

Re check your work.
Check your ECU, engine and wiring harness earth.
Compression?
Cam timing?
Manifold leak?
Blocked cat?
Does the turbo spin by hand?
Have you left a rag in the intake pipe. (dont laugh, I have seen it done)
Are you sure you havnt swapped sensor plugs over?
Throttle position sensor...did you move it. This will effect mixture (if you have one fitted)
Perhaps get the intake system pressure smoke tested. As you are working from manifold vacuum any leak will mess up all Daves hard work.
Good luck

I think its all been done to death will be checking the actuator compressions all good, definitely no rags in the systems. TPS reset, all joints resealed its a mystery