Hi, I need a little help finding this problem,I have a 98 s10 blazer 4.3 vortech engine v6,2wd,4 door,I am a rural mail carrier my truck drives 124 miles a day 6 hours straight,it will drive perfectly fine in the morning after about two hours of drive time it will start to buck when i take off from a stop,when i get to about 60 it will only stay that way for about 5 minutes and then engine will quit,it will start back up and run fine again for a short time,I have replaced fuel pump,filter,new o2 sensor,new mass air flow sensor,new plugs and wires,new fuel pump relay switch,I am now out of ideas and so is my mechanic,can anyone help?

 

Possible ignition module... and maybe a coil.

 

what does ignition module do?

 

I have been having the same problem, mine is in the shop being looked at they have replaced everything from the cat. converter,cap,wires,plugs,iac valve,o2 sensors, computer,ignition module and new fuel pump!! still problems!!

 

well,lord what could it be?

 

You will probably need to find someone with a good scanner like a Tech2 or equivalent that will let them "see" whats going on.
By the time you get done spending money changing parts, you could just pay a good technician for an hour labor and "know".

 

True,guess I'll send her to the doc again next week,thanks

 

Well, mine is at a chevy dealership and has had all the scanners put on it, carbon vac, fuel presure test everything they can do but can not find the problem!! Good luck with yours

 

thanks,I'll keep trying