Can someone tell me where the fuel sensors r located on the 4.3 engine...1995 blazer?

How is your o2 sensor? if it is bad it would make the car run rich and foul the plugs.

EGR valve sticking or bad vacuum leak, might be a place to start. I presume the ECM, control module are functioning properly?

additive? for what reason, for stalling? or just for fun added.
you didnt say.?????
if it was for bad running, did you read the container, ?
and add the correct amount on a full tank of fuel, if not , then you may have added too much, some additives are very bad,
next time use Techron fuel additive, (if you feel compelled)
if the car runs bad no fresh fuel, and all 4 sparks are fouled.
no additive is best. fouled sparks are from other reasons.
50 reasons. and not one is cured by magic in a bottle.
I run Chevron fuel in my car, so adding more benzene is of no help
ever.
you said plugs, that to me means, (????)_all 4 are fouled.
4 plugs changed, where they spec type spark plugs, J plugs.
and were the gapped to Geo Storm spec.
if new plugs foul? that means (all 4?) means its running rich.
top reason for rich are:
1: thermostat missing or stuck open (engine never reaches normal temp)
2: Sensors reading wrong,
The Check engine lamp, what does it do.?
Is CEL light glowing key on,. then out after starting, (no? then pull the DTC codes and read the problem)
too high fuel pressure, ask your mech to measure that. or DIY.
ECU stuck in limphome mode. check DTC codes for reason.
Dead , bad or weak sensors.
leaking injectors
Ask any ASE mechanic, to just diagnose the problem.
then you have your answer. but many shops never seen a GEO ever
and have no documentation. on these.
how ever alldata dot com has it.

Leaking fuel pressure regulator , or leaking injector's ,depends on injection system . ! it's only running rich on right bank. whatever that means . Your vehicle is a v - 6 has two banks . right side of the engine an left side of the engine . Bank 1 is where #1 spark plug is . bank 1 is odd numbers 1-3-5 Bank 2 is even firing #'s 2-4-6 . What fuel injection system does it have ?
Your best bet mite be to take your vehicle to a qualified repair shop.

Hi Dale,

Several factors can contribute to spark plug fouling:

- The air/fuel ratio may be too rich as a result of incorrect carburetor adjustment or a poorly performing fuel injection system.
- Worn piston rings or valve seals may allow too much oil to leak into the combustion chamber, leading to oil fouling.
- The ignition system may not be performing properly.
- Prolonged idling or continuous low-speed driving may keep the spark plug from reaching its optimum operating temperature. Using too cold a spark plug can lead to the same problem.
- A dirty air cleaner can create a too-rich condition which can lead to fouling.

Have each of the above checked and corrected.

Fuel, oil and carbon fouling can all be the result of different causes but, once a spark plug is fouled, it will not provide adequate voltage to the firing tip and that cylinder will not fire properly.

In many cases, the spark plug cannot be cleaned sufficiently to restore normal operation. Hence, I always recommend that a plug be replace, once it becomes fouled.

Cheers,

Scott


"If this has helped you in any way, please be kind enough to rate this solution"

Your Jimmy is running rich, air fuel ratio is not correct. Start with cleaning your MAF sensor, a dirty MAF sensor will cause your engine to run rich or lean, other causes would be a faulty fuel pressure regulator. Start with the simple and to common and try cleaning your MAF sensor, you can pick up a can of MAF sensor cleaner at most auto parts store like Auto Zone or Part Source.
Also make sure your engine is running at the proper operation temperature 190", cold running engine will cause the ECM to run your engine rich. Causing the back soot and fouling up your spark plugs and intake ports with carbon.
The ECM was programed to recognize the 4.3 vortec to run at 190" and anything cooler will cause it to run rich and poor on economy.
Thank you for using fixya and good luck.

2 things that you have to check on no starts every time. Spark at spark plug and fuel. Turn key to run position and listen at gas tank for fuel pump to run you should hear a whining noise. This will only happen for 3 to 4 seconds then it will shut off until engine starts. You can turn key off then to run every 3 to 4 to listen for fuel pump. You may hear the relay click off in engine area even if pump does not run. Fuel pump failure is pretty common. If pump is running pull spark plug out or put a spare plug into spark plug wire and have someone crank engine set plug on engine and watch for spark. This will give you a starting point. Hope it helps.

Car is running rich, can be a bad fuel pressure regulator or bad MAP sensor and can even be as simple as a bad vacuum hose that is disconnected. Regardless your engine is running rich (too much gas in to the engine from the fuel injectors) causing your plugs to turn black and foul, which is also causing your engine to sputter.
Start with the simple and check all your vacuum hoses, fuel pressure regulator and MAP sensor.
Good luck and keep me posted, be glad to help you get your car running 100% again soon.
Thank you for using Fixya

If your plugs are oil fouled, then either the spark is weak and not firing correctly in each cylinder (you would probably have misfire) Or the 02 sensors are bad and the engine is running really rich.

Sounds like two problems. P0300 and P0303 are possibly spark plugs. They could be a coil pack but I'm leaning toward a spark plug problem because of the other two codes - they're indicating O2 sensor problems. If the O2 sensors are screwed up, the car reverts to preprogrammed, rich fuel maps that send excessive fuel through the engine. The reasoning is, if the ECU can't trust the O2 sensors to determine how much fuel to burn optimally, it'll pump a bunch of extra fuel through the engine to keep it safe. Having too little fuel (aka running lean) can destroy an engine, so the ECU plays it safe and runs rich (too much fuel) instead. The consequences of rich running are relatively minor compared to lean running, but can and do tend to create excessive carbon buildup on the catalytic converter and O2 sensors, as well as fouling spark plugs.

First thing to do though is to swap the wires on your coil packs and see if you end up with a misfire code for the same cylinder #3. If you do, then it's the plug or wire. If it moves, it's the coilpack. Replace whichever part is faulty. You'll probably need oxygen sensors too, before you can clear all the codes.