95 S-10 Blazer 4x4 2dr

okay heres my problem started on a long trip about 500 miles at the 350 mark i start getting a hesitation while driving as i keep going i gets worse (no codes)(no ses) and then dies as i turn of the highway so at a lower speed. I take it to the dealer and he says its the fuel pump and test drives it and its still doing the same thing. Mechanic cleans the injectors and test drives it without knowing if that fixed the problem he test drives it and has no problems sends me on my way!!

i make it home about 150 miles and then later that week probably 50 miles later it starts doing it again so i take it to a guy i trust and he has it for days thinking it could be the computer,injectors or wiring harnes he fixes a wiring harness he's says was faulty, it runs well but still has a miss in it and runs rougher.

5 weeks later i take the same trip as the first one no problem, get back to town and it starts hesitating and sputtering upon start up. I take anothe rlong trip later in the week and 500 miles of hesitation in progressively gets worse nad finally quits 140 miles from where i need to be stalls as soon as i stop at a light and won't restart for another 1.5, and then runs roughly the 140 miles home.

i have alot highway miles on my car and i'm trying to figure out where to start with this problem with coil,fuel injector?????

oh and on my last trip the SES light came on but i tried to read it with my OBD II and it nothing would come up.

Welcome to the forum!

First step is find out what codes are stored. 95 was a transition year for computer controls on GM S&T series vehicles. It could have one of 3 different systems. Advance Auto Parts and Autozone will read the codes for free. Write them down and post them here. We will help you diagnose the problem.

Next step is check fuel pressure, here is a guideline:

Fuel pressure is not monitored by the On Board Diagnostic (OBD) system and therefore cannot set a Diagnostic Trouble Code (DTC), or illuminate the Service Engine Soon (SES) light.

Fuel pump operation:
The fuel pump circuits are designed to energize the fuel pump through a relay continuously any time the key is in the START position. When the key is in the RUN position the fuel pump will operate provided the engine is running. If the engine stalls, or is not running for any reason, the PCM/VCM will shut off the fuel pump after approximately 2 to 3 seconds.

Fuel pressure test:
Install the fuel pressure gauge to the test port near the distributor. Turn the key to the RUN position but do not start the engine. While the fuel pump is running, fuel pressure must be 60-66psi. After approximately 2 to 3 seconds, the fuel pump will shut off. Fuel pressure must remain between 55-60psi for several minutes. A drop in pressure below 55psi indicates excessive leak down. Possible places to leak are the fuel pressure regulator, the fuel lines under the upper intake manifold, a fuel injector that is stuck open, a leaking fuel line or connector, or the check valve in the fuel pump assembly.

Here is a link to an inexpensive, and adequate fuel pressure tester: http://www.harborfreight.com/cpi/ctaf/Displayitem.taf?itemnumber=92699 Accurate diagnosis of an internal fuel leak requires additional test equipment. In some cases it requires the removal of the upper intake manifold.

Hope this helps.

my code reader wouldn't show any errors, i will check the fuel pressure again but i just had the dealer put in a new one 2 months ago.

i wil also have to check to see how the injectors are operating, or the intake isn't leaking right??

thanks for the help!! got somewhere to start

The symptoms sure sound like fuel... Might want to check the fuel filter, you may have picked up some dirty fuel. A can of dry gas/heat/gas line antifreeze, (what ever you want to call it) might not be a bad idea either in case you got some water in with a fill up.

turned out to be a faulty wiring harness to the injector FYI!!!