I figured while I was at it, I'd see what you guys thought... No doubt this has to do with some computer issue. I have a 1995 Chevy V6 Vortec LS Blazer. I posted something earlier on about how it has a "missing" problem. Since that post, I now only drive it around town. (To afraid to go much further with it...) Here's what bugs the bejezers out of me. Sometimes I can start it up and drive it to the store or my folk's house and it will run perfectly. Other times, I start it up and it runs like crap from start to finish. The one thing I have noticed is if I punch it, it will get up and go without any problems. If I start off from a stop like I'm supposed to, it will spit and sputter right along. I paid a station here to find and fix what ailed it. The machine, of course, only shows "random misfires". DUHH! They checked this and that and put new wires, plugs, cap, etc. and charged $350.00 for that tuneup. I came and drove it home and then to a store and low-and-behold, you'd have thought they hadn't even touched it. It ran just as crappy as ever. One day, I had a daddy-daughter-date-day. We were going to go to a town about 35 miles away. I took the Blazer (for some reason) and the dang thing drove _perfect_ all the way there, around town, and back again! So~ tuneup, lots of gas treatment, new fuel filter, other things "checked", and I'm still left wondering, Thanks for your previous responses, any other ideas would be greatly appreciated!
I know so little about these modern systems . Does it have either a TPI Switch or an air flow sensor (" hot wire ") ? . Or maybe a MAP Sensor ? . All of those are common to the complaint you mention but different F.I. systems use differing items so your truck may not have these .
To tell you the truth, Nate, I'd have to check. I have no idea. This is exactly why when my 52 is rolling, I'm dumping the Blazer and driving my truck for the rest of my life. (No matter HOW much gas will cost!)
Zig, s10 blazer, right? If so, go to this website and study it. Seems to be a lot of big info and a forum that might help you with the problem. www.s10forum.com
I only have the one... You read my mind, Bill! I only have the one block, however, and it's spoken for. Wouldn't that knock 'em over though. I'd love to pull back into that station and say, "The problem seems to have taken care of it's self for good, could you check this and see how that could be?" Then I pop the hood and there is an inline GMC long block rolling away in there...
This will be where I place my money~ The TPS has my vote. It also has a MAP sensor, but I'll start with the TPS. It just makes sense. If I get the throttle past the normal (very limited movement) positions, Things go fine. But leave it around the normal driving range movements, and that where the trouble is. The fact that it's not an "always" issue makes me think that it's a sensor thing. Sometimes it "senses", sometimes it loses it's focus. Thanks for the ideas!
Had an S10 about every 2 years the TPS to be cleaned or replaced.I later learned that a clean fuel filter heped the longevity of the TPS. Bobby
Glad I didn't bet real money... New TPS, same old $hit. Come on Chevy~ WTF?! Ideas??? Stomp on the gas, it goes. Drive like your supposed to, phagidaboudit~ yeah, it goes, but I won't make money if I only drive it a quarter mile at a time, believe me!
Well... While this has been fun, I gotta take my foot off the gas sooner or later, and when I do... random misfires... Bad Chevy! Baaaaaaaaaaaaaaaaaaaaaaaad Chevy!!!
My Fix Zig I've been lurking on this sight for a couple of years now and learned quite a bit from you guys you are great! i have 1953 3600 and a1966 c/10 I play with. I have been dealing with the same problem you are dealing with on my sons 1996 GMC on and off for about 6 months. When it first started I went through it and replaced plugs wires cap and rotor was fine for a couple weeks then same thing again started looking again then noticed rhe coil looked like it had a burned spot on the sides of it so I replaced that. No change same thing. The next thing I did was I cleand the MAF & the throttle plate seem tto run better but not Quite perfect. But not perfect but drove it like that through the winter, This spring he bought a new truck and trying to sell the 96 and it starrted to act up again. I went through and cleaned the throttle plate and MAF again. No change! To me it sure seemed like a ingnitio problem so I checked all the plugs and wires they seemd fine so I went back to O'*****s where I bought the cap and they gave me a new one under warranty. Still the same thing. I give up! it has to be fixed. So I took to the shop where I worked as a mechanic for 17 yrs and asked them to check it out. I hate giving up and taking stuff in but I was stumped! They put it on their scope and said the spark was jumping all over. So they put in anoter cap and rotor from N**A. The truck runs better than it ever has. now we just have to sell it! 1996 GMC C1500 4.3 Vortec 5-speed. Hope this helps! Smitty
Trailing / Part Throttle Misfires Does this thing have a MAP sensor ? . (on old 1970's vintage MAP controlled FI systems , a bad / leaky MAP Sensor does this) Have you tried connecting a vacuum gauge to the open intake manifold to see what's going on at various throttle settings ? . This is why I HATE modern rigs ~ they screw up and then I get curious and wind up touching the danged things...
