loss of pickup

'89 2.5 class U engine....Was cutting out on load after warmup - would spit and stutter until I eased off accelerator. Replaced wires, plugs, fuel filter. No change. Had shop replace coils I couldn't reach (Thanks CTESLA !) cutout and sputtering has stopped, but engine seems awfully weak - have to really push it to get to 60-70. Am going to check wires again this weekend. Could other coils or misfires have damaged my wires ?

(Followup note - Is there a difference between the DR39 and DR39X coils? I believe the shop installed DR39's) <Standard Motor Products>

Thanks,
Mac

The wires could be your problem since if the coils were firing badly they could have damaged them. The wires are usually the culprit that causes the coils to go bad rather than the other way around.
There may be a slight difference between the coils but there should not be enough difference to cause the problem you indicate. If the car is running then you shouldn't have any issues with them once you change the wires.

Ok..put another set of wires on this weekend. Engine still seems weak, and idle is not as smooth as it was a few weeks ago. "Feels" like weak spark. Car was running fine till I noticed it buck and cut out when taking off from a stop. Have now replaced coils and wires (and fuel filter). No more bucks and spits, but very hesitant on a hill. What should I look at next ?
Thanks for all the help. Car has never had a problem that plugs and wires didn't fix.

How many miles on the car? If this is a high mileage vehicle you may be developing an injector problem. As injectors age they tend to develop a higher resistance than normal. As this happens they put less fuel into the engine and you have less power.

The other issue could be a blocked or partially blocked cat. If exhaust gasses can't properly escape then it will cause the car to seem sluggish.

Also take a fuel pressure guage and check the fuel pressure under load. The regulator could be going bad or the fuel pump. As long as you have decent spark then the next place to look is at the fuel system. If fuel pressure drops while driving then the problem is probably the fuel pump.

Check fuel pressure, cat and finally injectors!