Power surge on CM870???

[Rawze]

what is the boost gauge doing?

BTW: those engines are not supposed to be driven like a 'rocket' .. It is abusive and turbo lag and everything else is going against you. Especially on an 870, as the turbo is air actuated and sometimes you get a little more or less because there is no feedback for the turbo position.

what your doing sounds just like your fighting unpredictable amounts of turbo lag. That is the nature of an 870 with a turbo (or controller or air actuator) that is getting worn and starting to hanging up a bit. Does not hurt a thing is you drive it normally, and the lag will usually always catch up to it.

it ain't no damn race engine! ... ESPECIALLY if it has a million plus on it. - I guess the notion of sending a piston thru the block due to age, a million+ of wear, etc. and pushing it so hard like that hasn't occurred to you yet.

Drive it gently ... drive it by the boost gauge, keeping it to 20 psi or less, ... and she'll continue to make money for you a year or 2 more ... otherwise, I hope you got a spare engine laying around.