Alfa 156 V6 2.5 Not revving poor idle *FIXED*
Alfa Romeo 156
2.5 Saloon 2001
VRM:ALFA ROMEO 156 V6 24V TURISMO (MK1)
Engine # 324.05
2492cc 24v 189 BHP
Problem – Idles but revs up very slowly to a maximum 1,800 RPM, also erratic idle, cuts out occasionally but starts again straight away.
Every now and again car runs idles for a blip of a second but then idles rough again.
** FIXED **
Car came into us recently with snapped timing belt, customer had second hand engine fitted with various new parts, timing belt kit, water pump etc.
Car left premises and was running great for about two weeks, and then customer complained about loss of power.
We tried the throttle body reset procedure but to no avail.
On checking on the diagnostic machine it was saying that the throttle body was at fault so we got hold of the customers old throttle body ( as he took all parts of the old engine away) and changed it back over, still it had the same problem, we then tried the throttle pedal potentiometer attached to the pedal, still no difference, then we checked wiring to the throttle body and pedal all correct all earths correct (as the wiring connectors behind dash can be problematic) we noticed however that the negative on the battery was quite loose due to being a poor fit prior to us refitting it after the engine swap.
We then decided that the ECU on the engine was at fault ordered one up from a supplier quoting the Bosch number on the ECU, fitted it and started the car (key programs to ECU on first turn) the car seemed to idle better straight away, but still did not rev, we then scanned the vehicle, the throttle error had gone, but a couple of codes were still in it, one was MAF as we had checked that also, but the other was D600 which was a communication error between the key and ECU, these were erased and hey presto car revved and runs perfectly.
Hope this helps someone in the forum, thanks Dave.