So in Feb we bought a 94 S10 Blazer with 158,000 miles. Engine was recently rebuilt and appeared to be in great condition. Being in FL it is hot most of the time and a short time after buying it it began not starting. You can go out in the morning and it starts not problem, but if you drive a few miles, stop and shut it off and try to restart it won't. It hesitates but will usually start on the 2nd to 3rd try, but always starts.
The other day it started stalling. When turning onto a street it stalled out and wasn't re-starting. On the phone with roadside assistance to get it towed and it finally started. So get going get on the highway, and going 70 mph it just stalled out. Again refused to start, but after a 10-15 mins it started back up. It then stalled at a stop light and again didn't restart immediately. After that when approaching red lights put it in neutral and gave gas while stopped. Oh, check engine light is on, and we're taking it to have it read tonight. It didn't stall out.
So my questions are:
What's causing the starting problem?
What's causing the stalling?
Could the two problems be related?
Thanks! Any help would be greatly appreciated!

 

They most likely are related issues. Start with a fuel pressure test. Fuel pressure needs to be 60psi or higher key-on, engine-off and should not bleed down more than 2-3psi after you turn the key off.

 

Ok, so did some things to try and fix the problem, cleaned EGR valve and replaced fuel filter. Still having trouble so replaced the fuel pump. Now it won't start at all, not getting any fuel. The pump was hooked up just the way the other one was. You can hear it turning on when you turn the key. Any idea what could be causing this?
Thanks!

 

Did you check the fuel pressure before installing the new pump? What is it now, with the new pump?

Did you clean the tank out while you had it off?

 

And did you make sure to reattach the pump ground wire?

 

That tank is clean, the ground wire is on. The blazer will start and immediately stall. Try to restart it and it will just turn over and over. Let it sit 5 to 10 mins and it will start and immediately stall then when you try to re start it it will just turn over and over. I tried switching the two relays on the firewall around. no joy.

 

Fuel pressure reading?

 

Still haven't checked the fuel pressure, wanted to find out what the check engine codes were first. Had to buy the stupid OBDI code reader. Anyway got one code off it, code 43 "Electronic Spark Timiing (EST) circuit-low voltage detected. OR Electronic Spark Control (ESC)- circuit problems."
What does all that mean? Do I need to replace the ESC module?
Thanks!

 

Something did not sound right about your description of the trouble code so I looked it up on TroubleCodes.net and found that code 43 is dealing with the knock sensor output.

94-95 GM 4.3L Vin Z:
43 Knock sensor signal was either above 3.5 volts or below 1.5 volts for at least 20 seconds.

I would check to see that the knock sensor is connected and functioning properly. It is possible that the ESC is not properly relaying the knock sensor input to the ECU, but I would start with the knock sensor.

 

Thanks, someone that I talked to actually suggested the knock sensor as well. I do have one question, how do you know if its a Vin W or Vin Z. There is a W in the VIN, so does that mean that its a Vin W?