Rev limited to 4000 rpm

[jcq]

My 1988 BX 16 Valve started to show a lack of power below 4000 rpm highly noticeable when going uphill and does not rev beyond 4000 rpm.

Can anyone help ?

[Toddman]

Worth checking that the throttle position switch is working correctlky as this puts the ecu into idle mode and prevents the engine from revvingmuch above 3k.

It is the black plastic pack on the throttle body that has micro switches inside and they usually click when the throttle returns to closed position.

I posted all the details how to adjust them correctly on the old forum so if you are a member do a search if not I will repeat them here for you.

It could also be an ign fault such as the coil or ign amp breaking down this is quite common - of course it pays to check and clean all electrical connections on the ign components and airflow meter etc.
Could be so many things so without more details it wiil be tricky on a forum - don't forgfet fuel filter either.

Cheers
Luke

[Kitch]

Is it misfiring? I had a similar thing recently, which turned out to be a bolt coming out of the rotor arm and piercing the dizzy cap!

It was like hitting the limiter at about 3800rpm

[thanuttiscotsman]

hi there,
if you have a 16v and its not revving over 4000rpm you need to tighten the accelorator cable. only fast logical explanation. you can do it under the bonnet there is a clip you need to pull out theats all. or if like mine your cable length is adjustable you can do it that way too.

cheers rossco

[RobC]

may be the ignition module. when i changed mine for a new one it cut out at 4,000 rpm, or thereabouts.

[Anonymous]

If the connector block on the loom from the crankshaft speed/position sensor become corroded, the signal from it to the ECU is weakened and causes just the same symptoms that you describe. Mine did the same after a quick pressure wash prior to removing gearbox and this turned out to be the cause.
Tobytronicstereophonic.