What's Going On?

[Unofficial]

Lately my idle has been extremely low, and sometimes it will pulse a little bit (the RPMs) I don't have a tach, but trust me, it's low. I broke a vaccuum line that brought gas fumes back into the motor about a month ago, but I plugged it.

I bought a K&N filter to fit a new air cleaner assembly I got, but I don't think that has anything to do with it. Also, when I slow down, it almost stalls on me. I doubt my torque converter is going on me, the truck has 83,000 on it. And one last thing. When I give it a little gas, sometimes it will "bog" out. It's almost like I'm always in too high of a gear. Eventually it switches, but today I was getting it up to 40mph, and it started running weird, and it was chocking up and it just about stalled on me.

I'm in the process of getting a 350 rebuilt...

[Blazin]

Whats your trans? TH350? Your vacuum to your modulator on the trans good? Spay a lite mist of either around the intake to heads, carb base etc. If you idle comes up you have a gasket gone or a crack in a vacuum line.

[VileZambonie]

You need to give more detail on your set up. Year make model engine etc.

[Unofficial]

It's a 700r4...I think. It's an overdrive.

I replaced my intake gaskets about 2 months ago. I'm not very knowledgeable about all this. Where exactly is the tranny modulator?

Sorry Vile, 1987 r10   305/700r4  Like I said, everything has 83,000 miles on it.

[DnStClr]

Unofficial, your 700R4 tranny doesn't have a vacuum modulator to help shift. It has a cable attached from the throttle body called a TV cable (throttle valve cable) to the tranny  and replaces the vacuum line and modulator on the 3 speed trannies (the TH350, TH375, and TH400) This cable is a critical linkage from the throttle to the tranny and it's gotta be properly adjusted so your tranny will shift properly at the right speeds and load conditions. There is an adjustment procedure for the cable and Vilezambonie and others have described the procedure in other posts. Not the expert, but I hope I helped some. 
http://www.73-87.com/7387garage/drivetrain/tvcable.htm

[VileZambonie]

So you have a TBI system. Check the throttle body base gasket.

[Blazin]

I only said that as I didn't know what you had for a trans. The symptoms sounded like when the modulator hose is unplugged.

[Unofficial]

I checked the TV cable and it's tight. The housing is as far back towards the firewall as it can go.

[Dragon]

Choking or Serging with a TBI/Fuel Injection Setup would lead me to believe that you have a loose/disconnected Vacuum connection somewhere...  Since you started  having this problem when you put a new filter assembly on, I would go back and see if you didn't accidently disconnect or left anything not connected....  It is possible that the Vapor line that was plugged off, instead of repaired/replaced needs to be connected...  Even though you may not have known that vacuum line made a difference with the Stock Air Assembly, you can notice a difference with the Higher Volume K&N Setup....

Some of the Experiences I had when working with my FI Buicks and my TBI '89 K2500 after changing over to a Higher Volume Setup(Also check sensor wiring pigtails, cause it's quite possible for one to be loose, and still allows the truck to run)