Hi -

I have a 1989 740 turbo intercooler with 147K. Runs perfect until put under load for hill climbing or passing. Turbo buries into the yellow on steep hill climb, and one instant of RPMs jumping crazily with hesitation in a passing situation.

I replaced exterior fuel pump/filter at 125k and new spark plug wires. New plugs at 142k. New timing belt and throttle body cleaned at 145k. Mileage is steady at 24/25, 75 is on interstate is 2500 RPM.

Obviously a brick newbie, so any help would be appreciated. FPR? Is there a firetrap I need to clean?

Thanks.