I'm new here, just found these forums, great site!!

I drive a 2000 Blazer LT, 4.3 Vortec. (I'll do a sig at a later date).

My problem - When I first crank and head out onto road, sometime it seems to stall, than picks up and runs fine the rest of the day. Also when this happens, I can hear the engine "whine" through factory radio. At first I thought it was bad gas (Wal-Mart Murphy USA, its cheapest) so I switched, still does it. Today as I was backing out of the driveway, it totally cut-off but cranked back up fine. Got onto road and it did it again, started to stall, all interior and guage lights came on, then smoothed out. Went back home, cut it off for about 30 secs, re-cranked and it was fine all the way to work (22 miles). Like I said, I know if I hear the engine whine, I know it is prolly gonna do the stall thing. No whine and it runs like a top. Also, only does it the 1st time I crank, rest of the day it runs fine.

I really like the Blazer (prefer Chevy over all other makes) and I have only had it about 4 months. Any and all help really appreciated..

 

I really wish i could help you ... But i had a 2000 same as yours and it did the same things. I spent hundreds at the dealer tryin to find the problem and no one could fix it....I ended up tradin it in on the zr2 that i have now..... I hope that you can find the answer to your problem i would like to know myself...

 

Welcome to the site.
I don't have your answer, only ideas.
I would check all the engine grounds. There should be a ground wire on a bolt at the back (firewall side) of the cylinder head or heads.
Check the small ground wires from the battery to the fender or rad support. Look around for any wires from the harnesses that go to bolts on the manifold or firewall. Just wiggle them to see if they are loose or take a wrench and make sure they're tight. The one on the back of the head is a little difficult to get to (maybe use a mirror).
Like I said, just ideas.

 

Good ideas.. been speaking with a friend of mine, said Vortecs have problems with fuel pressure regulator? fuel injectors, and fuel rail spider set-up assembly.. Says it sounds like a fuel delivery problem, maybe taking time for fuel pressure to build up.. ??

 

If it is a fuel pressure leak down problem, simply holding the key in the 'On' position until you hear the pump shut off should build up fuel pressure so that when you crank it, it should fire right up. If this helps, then you'll have to dig further into the fuel system. You could also check the fuel pressure for leak down with a fuel pressure gauge through the shrader valve test port on the main fuel supply line.

Now other things that I would recommend are... Pull off the throttle body and clean it up very well with some sensor safe carb cleaner. Clean out all of the passages. It is possible that the IAC valve is getting gummed up and that it takes it more time for it to get adjusted for proper idle speed. Cleaning the TB can only help. You also may want to clean the MAF sensor as a dirty MAF can cause some pretty weird problems.

 

if you're hearing a "Whining" in the stereo... that sounds more to me like an ignition issue. several things can cause that whine first thing I'd do is check all your plug wires... do it at night in as dark as possible place lift the hood and fire it up and look around try to follow each wire and look for an arc sometimes you can even hear a "POP POP POP POP" if it's arcin' good... second off could be the distributor cap sometimes they'll wear to the point of the arc flyin' all over the place and causin' noise.... and THEN we have the coil... get a bad coil.... you'll get what's called a "Leak" in the coil.. and no this doesn't mean $h!t oozing outta it... a coil has sheilding to contain noise and if the coil is goin' or possibly the shielding pukin' out on it it'll "leak" noise... I myself would be more lookin' at the coil if I knew the wires and cap were ok... what COULD be happening here is.... (and I've seen this happen before to a buddy) the coil is JUST what it says it is.. .it's a coil winding and as you well know metal will expand and contract with heat/cold so you could have a winding that's goin' in the coil and when you first start the vehicle it's makin' a good contact then when it runs for a few seconds or whatever current through it causes it to heatup and the windings to shift around (causin' the spark to have nowhere to go and just load up in the coil possibly causin' your whining noise and then totally lose contact and make the engine puke out then heatup enough to move and connect to somewhere again inside it) you migth hit a junkyard and see if you can pickup a new coil for cheap and maybe test it to see.....

Just some info on that "Whine" it might lead ya back to what's goin' on...:P

 

Today, about 15mins before time to leave for work, I went out and cranked, went forwards and backwards several times to "warm" it up.. kinda sluggish at first so I really nailed the gas good, it spat and sputtered back at me. Turned it off and finished getting ready for work.. When I left for work, got onto my road, gave gas normally, still sluggish, by the time I got to around 20mph it finally smoothed out (about 1/10 mile) and ran fine all the way to work.. and no engine whine thru radio.. Also I have noticed this seems to only happen on the hottest days, upwards of 90 degrees or hotter..

Gonna replace fuel filter, air filter, PCV valve, and gonna add some carb - injector cleaner this weekend to see if that helps.. guess its a start..

 

pcv is prolly a good bet seein' as how they always clog on these things.... but if it's happening during hot.... then ya prolly got a thermal problem.... and I'd be lookin' more in electical systems.... (could be fuel but I'd say it'd be something in the electrical system causing the incorrect fuel delivery llike a sensor or something breakin' down under heat).... hope the pcv does it though.. if not keep postin' and we'll keep tryin' to help ya run it down... if it is thermal there are some "tricks" to finding thermal probs... :P

 

What are those "tricks"?

Another forum is telling me sounds like it is poss vapor lock..

 

You won't vapor lock a modern fuel injected vehicle unless you've got some SERIOUS heat on the fuel line.