Shudder upon acceleration

I have 94 Caprice wagon, LT-1, cold air kit, 160 thermostat and a throttle body air foil. It has been running fine up to now. It now won't accelerate when cruising and then try to
give it more throttle or stuff it. It just shudders and stutters and won't go. It's not really a miss. The wires and plugs are new but made no difference. Scanned it and it shows no
codes. Any one have any thoughts? Thanks Steve.

Fuel filter?

Could be the EGR, too.

Clogged cat(s)?

check yer vac hoses????

do you have datamaster? if so are you running lean or rich? any black smoke out the pipes???

my 94 had a miss and it ran like that until you went WOT, then it'd take off.

When mine did that, it was an EGR valve

My wife's 94 had the same problem. After replacing everything I could including the opti, I did a compression check. It was good but several of the new plugs had carbon buildup. I cleaned and re-installed them and also cleaned and tightened the connections on the aux battery post. There were a couple wires burned there so I put new ends on. The car ran great after that and hasn't given a problem since.

Jon

Thanks for all the replies guys. I'll try the fuel filter Sunday and hope for the best. If no change, I'll do the EGR valve. I knew you guy's would have some ideas.
I'll let you know what cures it. Thanks Steve.

Has the opti been replaced? Your description is a classic case of a failed opti.
A failed opti will drive fine under light throttle, but will just bog under medium to full throttle, and have no power.
A bad EGR will bog, and go.
Do you hear any funny noises when it bogs?

I lost my first opti in 1995. It was under warranty back then, but still a pain.

Well, it was the opti cap and rotor. Replaced them and it's running like it should. With 53,000 miles it didn't hurt doing the fuel filter as well. It's getting near time for it's long winter
nap here in Northwest Ohio. Thanks for all the help guy's. Steve.