power band ? or possible problem?

hey guys new here and still new to the b. i have had it for just about 2 months now. little info on truck 93 2200 5 speed efi roughly 150k on motor. the p.o. had cat replaced and said recent tune up but i am thinking maybe just plugs and wires and not cap/rotor.

here is my question
the truck fells like it runs out of power after like 3.5-4k. 4k and up just feels like nothing just feels like it gets up to 3.5k and the power band flattens out.

checked plugs and look good and the cat was replaced 2 yrs ago (have receipt for repair). just passed smog and i also checked it and timing is right on

i searched and only things i found were about trucks dying or falling on their face in high rpm and could be related to vacuum advance
just wanted to know if this was a normal powerband or what i should be looking for

thanks for all the help in advance

your EFI motor shouldn't have a vacuum advance on it, it should all be electronic. There is also a way that you should be checking the timing on the EFI models, a certain plug that you ground before checking IIRC. These trucks don't do too well past 3500 rpms, were never really designed for power. What are you getting for mileage?

A possibility could also be a clogged catalytic converter... but like emjay said, these don't have a whole lot to give after 3500 rpms. I usually shift around 2800 when accelerating moderately, 3500 is where I shift when I'm getting after it pretty good.

Having said that, mine will pull to 5000 rpm fairly easily in the first three gears.

it feels like you said steve so I am guessing it's just the nature of the truck. Cat had been replace 2 years ago so I don't think that to be a prob. Doesn't really feel like there is a problem with the truck, it runs really smooth just feels like runs out of power in higher rpm. But sounds to be alittle normal. How is it that I check timing on this motor? I just did the normal hook my timing gun up and check but it was said that I have to ground something?

I don't take my B2200 over 4000 rpm, so don't know.

Does it run out of power smoothly?
If so it's the same as all of them... just useless over 3.5krpm... it's a diesel in disguise I swear! lol.
If you can see smoke or anything suspicious at those rpm's that'll tell you something is amiss... perhaps black exhaust (not so much smoke) saying you're getting an incomplete burn.

Timing light: #1 spark lead for the "pickup", positive feed to positive terminal on battery, earth/negative to the negative terminal or just ground it somewhere
I'm sure you're doing that right so no drama.

Solution? KIA!!!!!!!

haha ya i does feel like a diesel .. feels like my duramax but it tries to fool ya letting you think it has more lol

im loving the little truck and have a few plans for it too. my fav. thing so far is the mpg and fuel costs , much better then my diesel

is advancing the timing on this motor worth anything? if so how far? or should i just leave it at maufac. setting and be happy lol.
i am always trying to tweak things (one reason ,my duramax is outa commission right now) also looking for few other suggestions for motor to make it run a little smoother i guess lol

sorry for all the newb questions .. i have done a lot of searching but most of everything is for the carb motor

I don't think that spark advance gives you much on these engines - I would leave it at factory spec (6 BTDC, I think).

It wouldn't hurt to try a little advance (as long as you're not getting any knock) and see if you get any noticeable difference, but watch the MPG's as you might find a slight increase in power, but it could be at a small (or maybe significant) loss in mileage.