'93 Suburban Weird Idle

[1993Suburban]

Hey all, wondering if you could help me out with yet again another issue i am having, (well i suppose not a huge issue but it is for someone as nit-picky as i am). 1993, 350 5.7 liter engine, automatic, 4X4. Sometimes, (like half the time) i let my engine idle, the engine sounds like theres a choke or something thats coming off and on. The RPM's lower for about a second and then come up for a second and then down for a second etc. It almost sounds like the engine is about to quit but then comes right back up to idle speed and then continues this in a cycle until i put it in gear. The other half of the time it idles just fine. It has always done this since i have owned it. Leaking vacuum tube? Maybe a tune up would help? Also what does a tune-up consist of for a fuel injected engine? Any idea's are appreciated and thanks alot for all your help.

[Fryall4]

Hey '93, Sounds like your engine is searching for an idle speed. I am not too hip on this problem, but many others here are. I am having a similar issue with my 93. Long story short, I've thrown all kinds of parts at it, and we are still awaiting the verdict from the Dr., LOL.
As far as a tune-up goes it would consist of cap, rotor, plugs and wires if needed. If doing the job yourself do yourself a favor and buy the brass terminal cap and rotor, not the cheapest one available from the parts store. Mine set recently cost $39.00. Remember, you get out what you put in. You can ohm out each individual wire with a multi-meter, if the resistance is over 30,000 ohms it is time to replace them. Fry-

'93 Suburban Weird Idle
Hey all, wondering if you could help me out with yet again another issue i am having, (well i suppose not a huge issue but it is for someone as nit-picky as i am). 1993, 350 5.7 liter engine, automatic, 4X4. Sometimes, (like half the time) i let my engine idle, the engine sounds like theres a choke or something thats coming off and on. The RPM's lower for about a second and then come up for a second and then down for a second etc. It almost sounds like the engine is about to quit but then comes right back up to idle speed and then continues this in a cycle until i put it in gear. The other half of the time it idles just fine. It has always done this since i have owned it. Leaking vacuum tube? Maybe a tune up would help? Also what does a tune-up consist of for a fuel injected engine? Any idea's are appreciated and thanks alot for all your help.
__________________
~Suburban Freak~