So I have been fighting this '95 from the beginning and I am throwing in the towel. As soon as I get it up to selling standards it's gone.
I struggled with fuel issues and finally broke down and got a reman spider. Ever since then it's had a loss of power and does not run as good as it did before. Also runs hotter which leads me to believe that there is a vacuum leak. I capped off the HVAC/transfer case vacuum lines so it's just EGR, brake and EVAP lines that could be leaking.
I'm guessing that the nasty state of the old spider was covering up this problem.

When running the Torque App on this it is showing that the PCM is pulling timing at all times which is not correct. So, it may also be a problem with the timing being advanced. I have messed with both the CPK and CPS but after connecting to it with a high-end scanner it did not even come up with the ability to do a relearn.

If there are no suggestions I will just sell this Blazer for as much as I can get in the state it's in. I don't have anything bad to say about the S10 platform in general but the CPI method of fuel injection combined with the incompatable communications of 1995 are more than I'm willing to put up with in a vehicle.

 

I rolled the dice and installed the distributor 1 tooth retarded from where it was. The scanner was telling me it was pulling around 20 degrees of timing which if my math is correct (360/2=180) (180/6=30) this would leave it at 10 degrees retarded so that the PCM can advance timing instead of pulling. If it throws a code I'll switch it back. All other vehicles I connect to show a timing advance around 20 degrees instead of pulling timing. Might also explain running got ever since I changed the spider injector.

 

My older sister had a 1995 Blazer some years back, she experienced the same problem my dad spent $600 having the fuel injectors changed and when that either didn't (or just didn't make my sister happy) he said to her "either you can get a new car, or you can spend a roughly equal amount of money having an engine put into it similar to the one in your brother's 1979 Camaro Z28 (which had a 350 LT-1 from a 1970 Corvette that was rear-end totaled swapped into it along with the Muncie M-22 Rock Crusher 4-Speed Transmission that was attached to it in the 1970 Corvette)... She ended up getting some new Pontiac

 

We're on the same page. I'm just trying to get it into the best shape I can because it's already listed on Craigslist and the local Facebook Auto Sales. I can't take it anymore. I'm having problems with my Pontiac too which will also be for sale spring next year. I like my GM vehicles but they sure do require a lot of my time. Repairs are quick and fairly cheap but at the expense of doing them constantly.

 

Woah, defiantly wasn't a tooth advanced on the distributor. Sure didn't like that much. Idled like a harley for about 15 seconds.

 

I'm maybe going threw same thing.
I have a power loss when it runs for 2-3 min. Starts to run real rich and pops a little bit.The throttle will surge when driving it like fall on its face you floor it and it goes like a bat outta hell than will sputter again when you drive at normal speed.
I put New AC delco spider injectors in it and the fuel pump relay also map sensor and IAC sensor. New Cap and rotor and temp sensor the one by the water pump neck. Also did a new muffler and tail pipe cause tail pipe was missing when I bought it a few months ago.Replaced the lower intake gaskets and the upper ones with the new spider injectors.
Brought it to a friend of mine who is a Ex GM mechanic . He thinks it may be the plugs are fouled on the one side and its building up gas not burning it out than when it does come out the fumes will burn your eyes while in the garage with the door open of course.He said once they foul on these 4.3 they do not and will not ever un foul and clear out.
I did buy new plugs AC delco and know they need to be gaped at 45k. I will do it this week end and if the solves this head ache I will kick my self... Oh well crossing my fingers.

 

Yeah, I'm pretty sure the plugs fouled when it was trying to run because it was very gassy when it finally died. That's my after work project for today. I've been through very fouled plugs before. I usually have luck pulling the plugs and giving them a shot of brake cleaner and a once over with a wire brush. At least enough to get them firing again.

 

Well I did mine today with the exact plugs gaped right and still runs like poo.