Still fighting this hesitation demon on an 89 240 wagon. 113K on clock, recently (last 3 months) in service after sitting for an extended period. Attempts to get maintenance up to snuff, I've replace the in-tank fuel pump twice now which does not impact symptons. New in-tank pump sock. New main pump, fuel filter (Bosch), and poor electrical ends on main fuel pump removed and spliced in new wire. Brand new marine grade 25amp fuse and holder under hood for fuel injection. Cleaned all connections on black connector on driver's inner fender that leads to battery. Above average correct battery. Posts cleaned. All fuse holders on interior cleaned with wire brush and all fuses replaced with copper fuses. I do not know the fuel pressure while driving. Have had some vacuum hose deterioration which reduced problems when a zip tie was applied to the vacuum nipple at intake manifold. Two fuel injection relays interchanged and no changes. Symptoms are an unexpected loss of power and if you feather the pedal, seems to have no power. Sometimes will just catch and go on, but most of the time all it takes is to turn the car off, sit for about 5 mins and start and go, mostly with no more problems. Does seem like it may be related to a less than 1/2 full tank, but inspection of the little rubber hose on the in-tank pump appears intact and without deformity. I'm beginning to wonder about the fuel pressure regulator whether it's a mecanical issue or one of vacuum. Air filter is new (Mann). New cap and rotor, wires and plugs (NGK), new timing belt and front seals (Volvo brand). Got an oil leak I can't figure out and the A/C needs charged, but rides very nicely on the new Michelins.

Thanks board memebers!

JBeechcraft