Running rough above 1500rpm´s

[Xpbernardo 0]

Following my error 34 reported in my other post, I managed to source not one but two original Bosch used purge solenoid valves. Error went away. Happy days! NOT......... Now car idles perfectly but if I do a kick down, revs will go above 3000rpm perfectly. If I accelerate slowly or hold the accelerator pedal, revs won´t pass the 1500rpm on the instrument cluster, although the engine rpm´s go above that but in a slugish mode. All this in Neutral. Car is undrivable like this. No errors on the ECU or engine light . Need to say that the AFM module is not a original Bosch one. It´s a LOWE Automovil one. Apart from that car is in original status. I´m lost again....

 

The strangest thing in all that is the fact that the rpm´s wont rise in the instrument cluster only when I accelerate slowly ...

[Xpbernardo 0]

Heeeelp

I'm thinking on coil or tachymetric relay... 

[SRDT 186]

There is no tach relay on a Motronic. New ignition modules can have this kind of problems when driven by a Motronic, or maybe it's the distributor.

[Xpbernardo 0]

It has a big relay on a yellow plug near the ecu. Isn't that the tachy relay? 

What can cause the rpm pointer sticking on 1500rpm while the engine revs higher than that?

[SRDT 186]

It's a dumb 5 pin dual output relay, the ECU is doing the smart part here.

The tachometer is using pulses from the coil so there is something going on with the ignition but likely not on the ECU side.

[Xpbernardo 0]

Yes. I can see in the diagram wire 112 runs directly from the Coil to instrument cluster on "L" contact. Same one that will feed tachometer from there

Edited August 22, 2024 by Xpbernardo