I have a 56plate 1.9CDTI Signum Z19DTH and having a problem with hesitation/judder/flat spot and would like some pointers to a diagnosis of the definitive cause rather than replace bits willy-nilly (that's what $tealers do best and I'd rather avoid that!).
I have had a look through all the EGR posts and have cleaned mine and also the boost sensor (both badly coked up) and I'll do the throttle body when I get a gasket. The EGR valve and the swirl valves work as expected when activated with a code reader OBD thingy.
I get an error code P1900 occasionally that disappears once warmed up and the error code is listed as below, no idea if its related...
"P1900 - Exhaust Gas Temperature Sensor (Bank 1 Sensor 1) not plausible with Intake Air Temperature, (51) - Not present"
Does anyone know where this sensor is? Somewhere in the exhaust and nearer than the engine than sensor 2 at a guess, but I have no clue where either live!
The MAF may be suspect, as the readings are 40 whatevers and I believe it should be 25 - anyone have a method of testing one for sure? MAF has been cleaned but didn't look gungy anyway. (The car is barely drivable with the MAF disconnected).
If I try to blip the accelerator quickly the pedal flaps around doing very little and if anything seems that the car could stall (in neutral). The fuel consumption has plummeted from 48 on a run to 30 ish .
Hesitation/whatever is at about 1500-1850 rpm.
Car is recently serviced. Oh and injector loom is blue capped and engine number is in the updated range, so injector 3 should be OK and the readings are -0.5 to +0.8 on the OBD reader.
PS Incidentally I'm in Birkenhead if anyone needs to use my OBD/Op-com thingy.