1996 GMC Z71 extended cab deceleration annoyance

[quick69gto]

I have recently purchased a 132,000 mile 1996 GMC Z71 extended cab, short box, 4X4 pickup, with a 5.7 liter Vortec and auto trans. It’s in perfect condition and bone stock (except for cat back dual exhaust and the problem existed with original single exhaust) but it has one annoying problem:
When driving and I take my foot off the gas pedal to decelerate, I don’t get engine braking until around 30 to 45 seconds later.
It will maintain speed for about 30 to 45 seconds then it will start to decelerate.
It will do this in town or at highway speeds using overdrive or not, AC on or not.
Is there a way to shorten this setting or is this a normal behavior for the ’96 Vortec.

Any help would be appreciated.

[east302]

I used to have a 1998 and I'm pretty sure it was like that too. I don't think I noticed it that much until I got new tires...the new ones had better tread (more rolling resistance, traction or friction, etc.) and that's when I saw the difference.

As long as the accelerator isn't sticking, you're probably fine. Do the rpms drop when you let off the gas?

[quick69gto]

Yeh I came to that conclusion also (sticking).
I am going to go thru the throddle body with some cleaner to make sure that's not the problem.
It is a high mileage truck so I'm sure cleaning it up will be a good thing.
It could be me that's the problem. I have never had a daily driver that was this new. My last vehicle was a mint '77 Jeep Cherokee with a built 360 in it and before that I drove a mint '64 Chevy P.U. with a built 383 stroker.
Anyway, I won't list all the older vehicles I've owned and still own, but you get my point?
Maybe it's the fuel injected, overdriven feeling that I'm not used too when I drive the GMC.
Give me some time to clean up the fuel system and I will let you know how it acts.

Thanks.