i have a '98 T10 Blazer with (aprox.) 182K (113 miles) on it. the truck has a stupid hesitation/shudder to it (in first gear only) and sputters/surges @ any cruising speed that runs around the 2 grand mark (or higher).
if you drive it like an old lady (ie: normal, light acceleration) the thing will stick in first gear (practically) forever, and sputter like mad up to 2500/3000 RPM-and stay there without shifting, until you ease up (ever so slightly) on the throttle.
if you "get on it", but not necessarily floor it, it will accelerate smoothly (but kills the fuel mileage of course). this issue has been happenig for awhile now, but used to disappear while towing (even an empty utility trailer would cause it to go away), but now it's constant.
another issue is while cruising (speed not relevant, only RPM). it starts to appear around 2000 RPM (usually 60 MPH), and gets significantly worse the faster you go. you can't drive the truck in Drive-at all-as it's like riding a bronco (the bucking kind, not the Ford kind).
i've only owned the truck since the end of Dec/08, and at first thought "probably needs a tune up". i did a complete tune up-wires included, and only use the best parts (ie: brass cap/rotor, no aluminum crap), but this only minimized the symptom's. the truck will idle as if there is no issue what so ever, and starts up every time (even during our last winter, which dropped down to -42 degrees Celcius, or -44 for you guys in the US).
i'm getting a P0147 code, and a P0300 code. i know i changed one O2 sensor (pretty sure it was the one @ the cat, gonna check), so i'm not sure if it's faulty (still under warrenty, so who cares), but the P0300 is driving me up the friggin wall.
oh yeah, i made sure the truck passed our Drive Clean testing here in the GTA (that's South Central Ontario) before buying it (i've gotten burned twice before on this test) and it passed with flying colours, so it was running well in the beginning. also, i've had the truck scaned (and cleared) many times, but they keep poppin' up (finally went and bought a half decent scan tool myself).
well, i guess i've ranted enough (sorry 'bout that), anybody have any ideas as to what the hell is this trucks issue?

thanks for all your comments.

 

sounds like my truck, lol. what type of spark plugs did you use? if you drive the truck for a while and get it hot and then turn off the truck and walk by the front, do you smell antifreeze? have you checked your distributor gear for any wear? these trucks are known for the symotoms you described.....

 

everything was B.N.I.B. AC Delco. funny, i might have smelled antifreeze (i'm pretty sure if the wife was asked, she'd say "i already told you that" hahaha). no i haven't pulled the distributor yet (wanna wait 'til the Summer trips up North are over this weekend).
these 2nd gen trucks are **** compared to the 1st gen. the only problems i had with my '92 was, blowing up the ring/pinion 'cause i always towed to much stuff (at once, hahahaha! had 13,803 lbs on my trailer once-ouch!) and breaking the 5 spd 3 times (the damn thing just didn't like 7+ grand shifts i guess). seriously though, this thing seems like (mechanically) it can't handle the strain of working, guess the engineers @ GM turned it into a ***** truck, listening to all the office workers complaining "it rides so stiff/harsh", or "it doesn't handle like mt Olds does".
what's up with the antifreeze odur (you think the gasket)?

 

if you smell antifreeze, its more than likely that your lower intake manifold gaskets are leaking. they too can cause that misfire. do a search under "intake gaskets" and you'll find tons of pages on that. these truck are known for this. also which antifreeze do you use? death cool? or green preston?

 

"Death Cool", hahahaha, i like that. yeah this truck still has the origional DexCool s**t in it. personally, i don't think the lady i bought it from (who was the original owner) ever changed the cooant. the truck had no heat (thermostat was a mucky mess), and still has a low running temp. i was thinking of having it power flushed before the winter.
i'm not 100% sold on a leaky intake gasket (but, i'm not ruling t out) as the plugs aren't fouled up, and any idea as to why it's more noticeable when the truck hasn't warmed up?

 

have you checked your fuel pump? check the pressure from the rail cause i had similar symptoms and it was that. does it ever just stop and studder, without any power whatsoever, to the point where she wont move?

 

nope. read my post, 'cause it's exactly like i sayin' it acting, no different.

 

i assumed you used all AC Delco parts for your tune up. even the spark plugs. next i would immediatly flush out the death cool and put striaght water in there with 1 bottle of 2 liter coca cola to disolve some of the barnicles that have formed in there from the death cool and drive it around for a bit. i would also look behind the AC compressor and behind the alternator at the intake gasket to see if you can physically see anyting antifreeze seeping. but if you dont, and you still smell it when the motor is hot when you pass by the front or open the hood i would guess you still need lower intake gaskets. i would also look in the upper plumemn to see if there is any small puddling of fuel in there. if so your fuel pressure regulator is leaking. and i would also pull the distibutor to visually inspect the distributor gear for any wear. thats a common problem too. and then go from there...

 

yeah bigdaddy, i was gonna pull the distributor next week and see what the bottom of it is like (don't really think it's that, but ya never know......).
as for the puddling (fuel or coolant) i haven't found any. but i'm gonna try the straight water and Coke to flush it out (i know Coke will strip rust away, not sure why i never thought about taking the crap out from inside the rad too).
i usually don't buy all Delco products for (tune up's) but was told these trucks like their products better (really?). and, since i know these trucks are waaaay more finicky than the 1st gen's, i thought i'd give 'er a try, see how it works out. hope everyone enjoys their weekend, i'm outta here in 2.

 

yes these trucks are very finicky and tempermetal pretty much like a girl. thats why i recommend AC Delco parts. however like on the lower intake gaskets, you can use Felpro there, because felpro actually make the gasket for GM but only in black color for GM....