Help sick s-10

I have a 99 s-10 that for the past 2 weeks has been acting strange. When Im driving on the highway and let off the gas, it doesnt slow down, just keeps on at same speed for several seconds before decelerating. Also sometimes when stopping at a light the rpm`s will stay high for a few secs after stop. And now when the engine is cold taking off in 1st gear(5 speed) it wont take throttle for a sec or 2, just stumbles then takes off.
I dont know if these 2 symptoms are related or not. No ck engine light, no codes.
It is a 4.3L
Thanx for any advice.

It could be a sticky throttle body. Spray some carb cleaner through it and work the throttle with your hands. Continue until it no longer feels sticky.

If that doesn't work it could be your tansmission

A quick update: As far as the throttle sticking, I checked with
a Pro-Link and the throttle is coming back to 0% but the
engine is still reving. It doesnt do this all the time and it is
worse with the a/c on. A friend told me it could be the idle
air control valve, that make sense?
Thanx

HI

Just a thought have you checked the throttle body base gasket?
It maybe sucking air under the throttle body.
good luck
Sparkey

The idle air control valve does make sense. If that's not it, you could have a problem with your rev limiter. You would have to hook it up to a computer to know for sure. As far as your problem with taking off in 1st gear, it's probably just because your transmission hasn't warmed up yet. The gear oil in the tranny is cold and still thick which puts a little resistance on the gears and they won't want to move very freely. It doesn't sound like the 2 problems are related. Did you check the throttle body visually? If not, I would suggest doing so, just in case. Nevertheless, it can't hurt to give it a good cleaning. Regular maintenance is a very good thing. Good luck

Ok first things first, it sounds like a vacuum leak to me, this will cause your engine to lean itself out and therefore rev high. To chack you base gasket for leakage get you propane torch out (trust me) start the truck, then turn on the propane torch (don't light it) point the propane at the base of the throttle body (or carb as some people like to call it) if your engine revs higher it means you have a leak and the propane is making it's way into your engine. You can also point it around your intake manifold area (right beside your valve covers on the throttle body side) this would indicate an intake manifold gasket leak. Your Idle Air Control Valve or more commonly called Idle Air Motor could be dirty, therefore sticking open and therefore (again) letting air into your engine causeing it to lean itself out and rev high. You will need a big ass wrench (like 1.5") the IAM is located on the pass. side of the throttle body near the back, it will have wires going into it (be sure to unplug it first) and is black in color. Unscrew this unit and take some throttle body cleaner spray and spray the cone looking part (at the end of the spring) then maybe brush it clean with an old toothbrush or something just as soft, do not use the wire wheel or brush! once it is clean do the same procedure to the throttle body side, spray inside the IAM hole and hit it with the brush. Then use the rest of the spray on the throttle body. See if that helps.

man my spelling sucks ass....sorry, just improvise my words....you means your sometimes....sorry

So this is OBD2 and it's not throwing codes?
Maybe thats a clue in itself.

I want to say but a TPS would throw a code.
I'd think any other sensor would throw a code in a OBD2 also.

Vaccum leak, but where?