Half Idle Rpm ...

[Dandu 0]

Hello,

 

I recently had to face a short moment of fright, as my idle went down to 500 rpm in the middle of heavy traffic. But the engine went on smoothly. During the acceleration the rev counter moved rather sluggishly. It appeared to me, that the rev counter decided to reveal half of the current rpm over the whole rev range from now on. I didn't check it out, while revving the engine to its maximum potential.

 

As far as I remember, the transplantation of the 2.0l turbo engine into a 205 usually comes with this kind of problem, the rev counter operates improperly. Usually a kind of technical device or circuit is implanted in order to double the rev signal. Does anyone know, where this circuit is usually to be put? I don't know, where to start looking.

 

What do you think? Is there a chance, that my rev counter itself has got a mechanical or electronical problem?

 

Much thanks in advance,

 

Dandu

Edited June 18, 2013 by Dandu

[Anthony 1,000]

It would normally be placed either near the coil pack wiring plug, or near the ECU.

 

Look for three or four extra wires that have been spliced in.

 

It could be that one of the diodes have failed (or the wire joining it to the loom has broken away) if it has a typical simple tacho converter installed - this would give similar symptoms with the engine running smoothly but the tacho reading half the actual rpm.

[pug_ham 241 3 Cars]

If I read this correctly. its on a 2.0l turbo conversion which means you have either a modified rev counter or conversion box to change the ecu digital signal to analogue for the original rev counter.

 

Can't help with where this box might be or if the rev counter was modified to work using the pcb moved wire method but this sounds lik your problem imo.

 

It does sound more like a converter is somewhere in the system & one of the resistors or a diode has died.

 

g

[Dandu 0]

You, guys, are just marvellous. Much thanks for your help! Will be scrutinised soon. Dandu