Juddering off throttle

[dazsir]

Hey! me again, well the car runs ok idling and at speed but when I come off the gas the car will judder unless I drop a gear and the revs lift.

Any ideas what might be wrong?

Thanks guys

[MikeLMR]

not too sure on this one, does it idle OK ? is it pulling OK in all the gears ?

[Don Pamponi]

Dont think of these engines as similar to a piston engine.  They HATE low revs.  I found it weird in my 1st rotary, you just cant drive them below 2000rpm.

[MikeLMR]

they shouldn\'t judder off throttle though and unless you are really taking the p1ss with the rev\'s my 1st gen will pull very cleanly from low RPM\'s no juddering

I\'d say check the ignition parts, plugs, dizzy cap, rotor arm & possibly the leads, 1st gens seem to like them to be in very good nik to run properly.

I\'d also check the fuel filter, it isn\'t very likely to be the cause of your problem as you say its off throttle but they get neglected and old fuel tanks have a lot of cr@p in them.

[dazsir]

Thanks for your help fellas.  The car idles beautifully @1000rpm, the acceleration is clean and purposefull so I was and still am a little confused as to why the car will judder off throttle, like you mentioned the car seems not to like low revs so I drop a gear to avoid the juddering.
I will investigate at what point the juddering begins to see if it is the same rev point, which I would guess would indicate something like the carb, otherwise other things would not be always at the same point would they? Law of averages and all that!

[MikeLMR]

1000 rpm is a little high for normal idle, I suspect someone has been playing around with the carb. IIRC it should idle at 600-700 rpm.

have you checked the plugs etc. ? they need changing frequently on rotaries

[diabolical1]

i\'d inspect the cap and rotor myself. however, are you sure there\'s not a small vacuum leak somewhere? that could cause the increased idle (and i\'ve seen them do it smoothly, too) and wouldn\'t show itself much when in the upper RPM ranges.

[g11ary]

Is it possible for the juddering, to be a mounting somewhere? Sometimes low rpm and speeds show these more.