I am hoping someone can provide help on the hesitation problem I am
having with my 95 Blazer, It is a 4dr, 2wd V6 4.3. It starts and idles fine, however
when I put it in D and press the gas it hiccups and hesitates. Me and my friends
have already check fuel filter, and replaced the Idle Air Control Valve. In the last
year i have already replaced the ECM, EGR, Spark plugs and wires, and distributor.

 

Have you done a fuel pressure test on the truck? When was the last time you inspected your spark plugs? Are they clean, showing a lean burn or clogged?

 

+1, also try cleaning the MAF sensor.

 

Let me know when you figure this one out.

My truck has been sitting in the driveway for over a month with the same problem.

NOTE: I AM NOT GETTING A CHECK ENGINE LIGHT!!
And YES it works; I made it come on by unplugging my MAF Sensor to make sure.

I have noticed when I first start it up it runs great for about a minute or two.
I mean it runs like a brand new one but after it sits there and idles for about 1 minute it seems like the timing is off or something and it will backfire if you crack the throttle open really fast.

I'm letting mine sit until I get some extra cash to go at it again.

I've replaced the following with mostly AC Delco or Delphi parts;

Fuel Pump
Fuel Filter
Fuel Injection Spider w/ new pressure regulator
Distributor Cap
Rotor Button
Spark Plugs
Plug Wires
Camshaft Position sensor
ECM- With a known good used one flashed to this trucks Vin#
Map Sensor
Idle Air Control Sensor
Throttle Position Sensor
EGR Valve
Purge Valve
Alternator
Catalytic Converter

Tested:
· 02 sensors
· Crankshaft Position Sensor
· Physical Timing (with dist cap off turn crank back and forth to get a approx degree)
· Ignition Switch (connections/ground/hot)
· Did the wire wiggle test to see if it made any difference when I wiggle the wires around



I don’t know where to go from here but when I figure it out I will post it because this seems o be a common problem with these aggravating little pains in my ***.

 

well just got back in from the garage, plugs look great and my 95 does not have a MAF.
Replaced the fuel pump today because i had already bought it and have the same issue.
Idles fine, upon acceleration it lopes before it is willing to go.

 

viper1ex19, The OP has a 95 with CMFI, your 97 has CSFI: two totally different computer control and fuel injection systems requireing totally different diagnostics. Best if you start another thread, we can help you diagnose yours in that thread.