kv rev limiter

[stoop44rio]

my 90 with a kv hesitates under hard acceleration. it feels just like the rev limiter kicking in only at about 3500-4000rpm. in fact im 90% sure its the rev limiter. the cars had new plugs, leads and filters. dizzy caps recent too. rotar arm next to change but i dont think this will cure it anyone any ideas??

[Isimmo]

Originally Posted by stoop44rio

my 90 with a kv hesitates under hard acceleration. it feels just like the rev limiter kicking in only at about 3500-4000rpm. in fact im 90% sure its the rev limiter. the cars had new plugs, leads and filters. dizzy caps recent too. rotar arm next to change but i dont think this will cure it anyone any ideas??

There are 2 types of rotor arm, the KV type should have a centrifugal spring loaded centre section, this acts as a rev limiter... Whilst the Ur's had just a basic rotor arm...

On the KV type arm, the spring can become weak and set a low rpm limit... our RallyRep when we got it was at 5200rpm... So I (as I have done several times before) just binned the spring and the slider from the rotor centre. This then leaves the Hall Sender to do the rpm limit at 6500rpm approx.

[Puglife]

Wont be rev limiter, thats up near 6500 (trust me I've found it on occassion).... May be a faulty rotor arm, they work on centrifugal force which pulls back the contact at a specific rpm....

Simmo will prob have the answer as this is a known problem RE: kv engine at times.

EDIT: Simmo beat me to it

[stoop44rio]

thanks men, i think thats it!! looked at the rotar arm earlier but theres defo no springmost likely wrong one then? hope so-will keep you posted

[Booty]

Annnddd don't forget the fuel pump relay also has a rev limiter fitted into it's circuitry too. German and Swedish do the lot, I'd change them all to rule out a vacuum pipe braking down ( closing up ) under load / pressure. The KV runs critically on vacuum big time. If you need to know more then pm me and I'll go through the bits to look at and check.