5 replies to this topic

[pebbledesigns]

Hey Guys,

 

My new mini has a situation when I pull away from a standing start. Particularly when I am at a junction and another car flashes me to go. Therefore, my revs are roughly idle (below 1.5k) and then I immediately put my foot down. At that time, the pulls off but then very quickly feels bogged down. Sometimes I am able to blip the accelerator to pick the revs up higher but other times i find double clutching works better.

 

The mini is a 1998 Rover. Stage 2 (or 3, not exactly sure) MPI. I have checked the engine over for loose wires, pipes but it is a really clean car.

 

Question is, what would you do? 

 

Would you take it to a rolling road for them to have a look at the ECU?

Or, take it to a classic car garage?

Or, if anyone can help, is there anything I can check / replace first before the above options?

[Earwax]

Sounds like , you just maybe got startled and were a bit too quick on the clutch .... near stall.  Both the rpm lift and the slight slipping of the clutch are a means to help the engine catch up.. even though the mini is  lightweight  , there is still some mass to overcome ......    I would attempt to re- emulate the situation a few times ( particularly uphill) to see if there is a fuel stumble  or it is maybe just technique as above.  If fuel stumble ... check your fuel filter first  before going off to a garage.

[ACDodd]

If the engine is fitted with 1.5:1 rockers these do produce an off idle bog on the spi and MPI type engines.

Ac

[pebbledesigns]

If the engine is fitted with 1.5:1 rockers these do produce an off idle bog on the spi and MPI type engines.

Ac

 

Yes! You are correct, they do have these fitted. Can this be 'fixed' / improved?

[pebbledesigns]

I have found on another post:

 

"P.S. I have a set of 1.5:1 roller rockers from Minisport (I got buying fever and went and got them) but now I deem them un-necessary due to my change of cam spec as they would make the car unusable below about 3000RPM!!! I now wish to change to 1.3:1 as this will be much more usable and will be kinder to my valves". 

Interesting reading another reply...

"After a week I was fed up with the loss of low down pick up and power, constantly having to push the revs even in light traffic just to get the engine respond in any meaningful way. So I changed back to the standard rockers and I was much happier, as was my engine."

Looks like this is my issue...

 

 

 

 

 

 

If the engine is fitted with 1.5:1 rockers these do produce an off idle bog on the spi and MPI type engines.

Ac

 

Yes! You are correct, they do have these fitted. Can this be 'fixed' / improved?

 

[nicklouse]

High lift rockers lose you low down torque but give small top end BHP increase.

 

pointless on a car that does not use what most of the time.

 

and as a general rule of thumb if you are fitting high lift rockers you fitted the wrong cam.