I have a 99 zr2 BLAZER, 4.3 vortec of course, and im having this problem with it sputtering down the road. Its been happening for about 3 months or more. I cant figure out for the life of me whats going on. Comming from an 85 k20 silverado lifted 9" with a 350 and no sensors, im ready to scrap this thing! The idle is fine, i can sit there an rev it without any misfires or anything, but as soon as i put it in gear and drive down the road, it starts sputtering. When i stomp on it, its fine, doesnt sputter at all. I can feel it sputtering at about 55-75mph also. Ive replaced o2 sensors, cam sensor, crank sensor, full tune up 3 months ago, and its in the shop right now getting the trans rebuilt (blew second gear ). Ive hooked up the code scanner and found the "crank shaft to cam shaft position correlation", Ive also found 2 codes for misfires, on 2 different cylinders, cant remember which ones. Now i have done some research, and narrowed it down to a worn distributor gear, or timing chain. Unless im missing something, any help would be awesome, thank you!

 

Id like to know about this as well.. mine kinda/sorta does the same thing, but weirdly enough only when shifting from 1-2 and from 2-3. Kinda starts sputtering but when i let off the gas and then hit the gas again it shifts normally and is fine after you get passed 2nd gear. Did you ever resolve yours?

 

Actually I never figured it out. The only thing I can think of is a worn distributor gear, or timing chain, I guess those are pretty common, ill start with the distributor first time seeing as its easier lol

 

"crank shaft to cam shaft position correlation", you did have them do the CASE relearn when it was in the shop...right?

 

I'm here for the same problem with my 99 4dr 4wd. Is it possible that this is a fuel delivery issue? Reason I ask is that I'm getting funky readings on fuel pressure, ie: key on, engine off- 64psi, but as soon as the pump primes and stops, drops sharply to 56 or so, but holds for 10 minutes. Running- 58 steady. It sounds a little low but the funky part is when I isolate the pump (checked just before the filter), the reading is the same. I've seen on this site and others that it should be over 70, possibly up to 100 psi at that point since the regulator isn't in play there.

Am I misreading the posts? Lord knows my eyes are burning from reading 40 threads, not to mention the gas fumes lol.

It would also be prudent for me to mention that before I knew any better, I put an aftermarket pump assembly on it (about a year and a half ago) so I've just been waiting on it to fail since I've learned how picky these things are when it comes to replacement parts.

 

Crooked, it would be best to start your own thread with the problems your having, its free!

 

sorry it took so long to reply guys,i couldnt find the post again! well i tore my distributor out and took a look at it, the teeth were sharper than my knife!!! so i ran down to the junk yard and $20 got me a used one. i cleared the codes and sure enough that worked! no more sputtering but of corse with my luck, the sputtering came back and now im mad and ready to scrap this turd. The code read "cylinder 4 misfire" and then an o2 sensor, but no "correlation" code. so im not sure what else it could be, maybe distributor cap but im not gonna go throwing money at it untill i know for sure what it is, im dam near $10,000 in the hole already! any help would be much applied!

 

Swap plug wires with another cylinder, drive it and check the codes again. If the misfire followed the wire, put a new wire on it. If it didn't follow, swap the plug with another cylinder, drive it and check the codes again. If the misfire followed the plug, put a new plug on it. If the misfire continually stays on cylinder 4, check compression & cylinder leakage. Post your results.

Edit: Did you take care of the P1345? Did you perform the crankshaft position sensor relearn after replacing the crankshaft position sensor? (mandatory). Did you check & adjust camshaft retard after the distributor was out? (also mandatory).

 

I didmt do the relearn or check the camshaft retard, when I took the distributor out, I marked it so it went back in at the same place, after I put it all together, I erased the code and it never came back. I didnt have a problem with it until a couple weeks after that

 

If the P1345 did not reset, it means the distributor gear is meshed properly with the camshaft, that's all. It does NOT mean camshaft retard is ok. Camshaft retard data might not even be "in the ball park". The crankshaft position sensor relearn needs to be performed and camshaft retard set correctly, before any acurate "engine running" diagnostics can be done. All calculations that the PCM makes are based on correct input data from every sensor. If the input data is not acurate, the engine will not perform correctly.