Omega Owners Forum
Omega Help Area => Omega General Help => Topic started by: haydnm0 on 29 March 2007, 01:06:31
-
my 2.5 v6 has been suffering from quite a definite flat spot so i had a friend hook it up to his diagnostic.
it has flagged up a problem with the maf sensor so that's easy enough to cure but it also came up with
hall sensor switching on and off
engine pulse sensor switching on and off
all we can get off the diagnostic is that it is NOT a TPS or crank or cam or o2 sensor so eliminating these
has left me a bit stumped any ideas greatly received
cheers friends
-
Something I learnt from Mark a long time ago....
Don't take the results from a diagnostic machine at face value. They are reporting the symptoms, not necessarily the problem... :)
MAF sensor rarely fails on the V6, however the reporting of that being faulty is often a symptom of the crank sensor starting to fail.
Only sensor that works on the Hall Effect is the crank sensor to my knowledge.
What part pf the rev range do you get the flat spot?
-
try the "paperclip test" - instructions here (http://www.topbuzz.co.uk/info/fault_codes/fault_codes.htm) - then let us know what that comes back with.
When my crank sensor wiring failed I got code 19 (crank sensor incorrect signal) but ALSO a code 74 (MAF high voltage) ... go figure!
Codes were cleared by the garage who fitted the sensor, neither code has returned since ...
-
When my crank sensor wiring failed I got code 19 (crank sensor incorrect signal) but ALSO a code 74 (MAF high voltage) ... go figure!
The poor ECU is doing it's best. Since it's not seeing some crank pulses the poor think thinks the engine isn't turning over so fast and the MAF tells it about all that air going past so what does it do? All it can do really is report everything and hope the engineer doing the repair can put two and two together. Unfortunately dealers seem to use techs who are trained to replace what it tells you has failed and know nothing about diagnostics.
-
the flat spot is between 2.5k and 4.5k but only on hard acceleration i haven't had any work done yet.
they did clear the codes at the garage and none have returned yet
-
hall sensor is cam sensor normally ;)