Millers VSP Plus

[jimbo]

Hi all,

My Sprint has a bit of a cough between 2000 and 2500 rpm. If you are incredibly delicate on the throttle you can 'stroke' it through, but it's a bit annoying as when you change gear the new gear tends to end up smack in the middle of the 'zone of uncertainty'.

Amongst other things I thought I might treat it to some Millers VSP Plus. Is it worth it without a retune or will I not see the benefits without tweaking the carbs? Any other reasons to not give it a whirl?

Thanks,

James

[nebogipfel]

The only reason I can think of not to use Millers is that Castrol Valvemaster Plus claims to do the same thing and is far cheaper to use at 1ml per litre of fuel.

As to the question of improving your flat spot, my guess would be neither will help.

[denicholls2]

Hi all,

My Sprint has a bit of a cough between 2000 and 2500 rpm.

The RPM seems a bit low (I saw this around 3000-3500 in the Europa) but this could be "lean stumble" where the idle jets run too lean at the top of their service RPM. The test for this is that the car won't do it if you're into the pedal (the accelerator pumps supply the missing fuel). It's a steady-state problem running lean idle jets near the point of cutover.

Just a thought. If so, correctable with either bigger idle jet or (IIRC) smaller air corrector.

If the plugs are black, could also be leaking (worn) fuel inlet seal or, if electric fuel pump, too much fuel pressure.

Might also be a vacuum leak, check boosters first if equipped. Best troubleshooting starts with plug condition after a long run at this speed.

Other options are electrical -- points, condenser, rotor. All less likely if Ignitor equipped.

My money says snake oil won't fix it.