i have a 95 blazer with the 4.3 vortec engine. It started running rough (surging 200-600rpm) it does it at idle and under load.changed the dist cap,rotor,plugs still does it. now it has started to pop through the exhaust any suggestions would be appreciated it shows no trouble codes

 

95 used two different computer control systems. Under the instrument panel on the driver side is the data link connector, which style do you have?

 

it has the obd2

 

Rough running accompanied by the exhaust backfire, I would suspect a lean misfire possibly cause by a restricted poppet nozzle. If that's the case, a professional fuel injector cleaning might cure the problem. If the service engine soon light is on, or flashes, there should be a diagnostic trouble code, (DTC) in memory which would help in diagnosis.

 

when was the last time you changed the fuel filter? i would start with that.

 

My 95 gets to running a little rough and the ses light blinks about like a turn signal light and its always the same thing - the wire to the #6 cylinder spark plug is burnt up inside the boot on the spark plug. Replacing that one wire will fix it every time for a few months to a year or so, then it does it again.

No codes from this.

No idea why that one wire burns up unless its working its way loose off the plug for some reason. I have found it off the plug (but not yet burnt up) when I started doing checks on it every so often. If I can keep it pretty much plugged to the spark plug the end of the wire in the boot doesn't burn up (from arcing).

The 96 doesn't ever do this (same engine, etc.) but the 95 is just a pain in the butt.

 

A blinking MIL is a sign that the ECU has detected a potentially damaging misfire condition. You do not want to take this too lightly.

If you have a problem on a particular plug, have you tried replacing the plug along with the wire? Is there anything pulling at the wire?

Also, when you had the ECU scanned for codes, did you use a scan tool capable of reading both OBD2 and the maligned OBD1.5 systems? You could have either.

 

all plugs and wires in good condition. now it seems to have a high idle around 1500 rpm but it does not do it all of the time fuel filter is new sometimes it dies for no reason and when you try to restart it the fuel pump makes an odd sound like its straining to get fuel the pump was replaced in July 2010 as was the injector this is driving me crazy

 

I finally found my gremlin going back over things one more time was rechecking my plug wires with an ohm meter and noticed that one of the wires would read good depending on how it was held(broke wire) i replaced it and now its running like a champ thanks for all of your input