Tach Problems

[munz_clio]

clio 172 2004

ok so i installed my autometer tacho a few months ago and all readings were at around 40 percent of the actual rpm.

the above was connected via pin one orange cable on the coil pack to the green cable from the taho

what i did today was connect the green cable from the tacho to the orange cable and also to the cream pin two cable on the coil pack it felt like it was losing power. but this was done in a very temp' manner to see if it would work. what i was thinking is if connect the orange and cream (pin and 2) would cause problems could i connect my green cable from the tacho with a one way current flower and than connect it to both cables.

the reading was correct from the last test

cheers all

 

[cliocc]

No don't even think about it! That’s just hassle and you'll bl;ow your coil pack. The reason you’r getting a 50percent reading is that as the coil pack has only 4 wires and two of them are used for 12V supply and ground. The other two carry the signal from the ECU to the coil to control which plug to fire. As far as I can work out from the small amount of time I’ve spent looking at it, the coil pack works like a logic trigger so for example if one signal cable goes high plug 1 fires, if the same cable goes low plug 2 fires. Anyway that might be totally wrong but you can see why you'd be getting a 50percent reading.

There is a better way. Get the signal from the dash taco feed which is as it turns out is a full 4-cylinder ECU “manufactured” signal instead of 2 cylinder signal.

Alternatively, in the car unless you have a cup it should be pre-wired for air conditioning or have air conditioning. The air conditioning brain seems to need a taco feed so Renault put one in to the AC brain. Now double check this on your model but mine has it on the middle wire on one side of the gray connector going into the AC brain. I can’t remember pin number for sure as it was years ago I played with mine.

The ECU sends a full taco signal to the AC and the Renault taco in the dash so you should be able to hijack a signal from one of those places.

Oh and your Autogauge should still work from this ECU “manufactured” signal.

 

[munz_clio]

No AC

 

[cliocc]

Yeah mine has no AC but was pre-wired for it. Look up under your dash in the drivers side. The unused connector should be clipped in view towards the middle of the car.

 

[munz_clio]

was orig' a 1.2 16v got a 172 ktec conversion so cant see that con' being there

 

[munz_clio]

anyone no the tacho wire behind the dash

 

[munz_clio]

ok ive tried pin 1 and 3 at the ecu not them