Why is my rev counter not working?

[Martin347]

I have just put a 318is engine into a 325i and my rev counter isn't reading correctly. It seems to be reading far too low rpm. Is there anything I can do to solve it or do I need to buy an aftermarket rev counter?
Thanks, Martin.

[dazleeds]

did you swap the plug in the cluster for the 325 plug??

if not thats ur prob

[gcorky]

did you swap the plug in the cluster for the 325 plug??

if not thats ur prob

ditto what daz said as you are running 4 cyls instead of 6 ...you need a 318 coding plug.

[Martin347]

When you say 'plug in the custer'. Which one do you mean?
Thanks, Martin.

[dazleeds]

on the front of the cluster on the right hand side youll see a white plug bout 2inch ya need to put the plug for the is engine in to there

[Martin347]

Sorry, I might be being abit thick here but what do you mean by 'the cluster'.

[gcorky]

Sorry, I might be being abit thick here but what do you mean by 'the cluster'.

take out trim from in front of your speedo/revcounter etc,and on the bottom right is a plug in module......aka coding plug..

[Brianmoooore]

The iS four cylinder engine produces two pulses per rev to drive the tacho; the 325i six cylinder engine produces three pulses per rev.
All E30 instrument panels are the same (except M3 and some early ones) so information on the number of cylinders and fuel tank capacity is contained in a separate plug in unit on the front of the instruments, behind the trim panel just under the instruments and above the steering column.

[Martin347]

Swapped it, everything is working fine now. Thanks for everyones help.