95 GMC 1500 engine problems.. stumped

[Abstrakt123]

ok so firrst the basics
1995 GMC Sierra 1500
4.3L V6 4X4

___PROBLEM___

so in the past few weeks i have not changed a single thing since the problem has arised.
i have already replaced the Starter, Fuel Filter,Air Filter, Spark Plugs, Water Pump, Every Gas Fuel up I use Seafoam or IsoHeet, new muffler (thrush pipes)
Symptoms.
-it only happens certain days sometimes just for a minute others. it will do it no matter what
-will start to sputter like its not getting enough fuel or bad spark but that wouldnt make sense if it occasionaly does it only sometimes. which made me eliminate fuel pump and spark plugs
- the sputter consists of massive loss of power even sometimes to the point to where no matter how much pedal u lay down it wont even make a noise until u floor the pedal and then it will kick and be totally fine...until you let off the gas again. i mean litereally no sound from the engine not even an attempt at noise( i have a loud muffler so u can always tell) sometimes when u let it try to recover it lets a huge backfire sometimes a couple before it starts moving again.
- somedays it will rough idle weather its warmed up or just cold. and it will sit there and fight with its rpm. starts to idle fine. starts sputter and dipping to low then revzs it self up,. comes to an idle and a few seconds after it will begin to start dipping over and over until it finally will just sputter and die. but it will start right back up everytime. its more of an annoying nuesence then anything

if anyone can help me at all on determining what could be causing this issue without sinking tons of money ( i dont have) to replace parts till i finally find the right one

my opinion.. its either of the following
-Mass airflow sensor
- distributer cap
-loose wire
- oxygen sensor
those are the only outcomes i see any ideas please please let me know i love this truck all to much to want to part ways and give up

 

[rdm1465]

The symptoms you have described leads me to believe that it is one of a couple of things. First inclination is the Mass Air Flow sensor, or that you have bad fuel. I know you mentioned that you have used fuel stabilzers. But, if you already had enough moisture in the fuel (water), then it will do the same as you described. I would try flushing out the fuel system and put fresh gas in it first, probably cheaper than a MAF sensor. good luck

 

[Abstrakt123]

Ya But I Mostly Put Isoheet ( red Bottle) and isnt that a water remover?? so therefore it should be perfect ( by The way its winter here)

 

[pondscum]

After the service manager at my dealer tried to sell me on the idea to buy moisture "remover" with every fill up, I had to read and think about this. Do thee products realty "remove" water? And if so where does it go? Like my body, there is only a couple ways out! That water still has to be passed somehow?

 

[Molson02536]

ok so firrst the basics
1995 GMC Sierra 1500
4.3L V6 4X4

___PROBLEM___

so in the past few weeks i have not changed a single thing since the problem has arised.
i have already replaced the Starter, Fuel Filter,Air Filter, Spark Plugs, Water Pump, Every Gas Fuel up I use Seafoam or IsoHeet, new muffler (thrush pipes)
Symptoms.
-it only happens certain days sometimes just for a minute others. it will do it no matter what
-will start to sputter like its not getting enough fuel or bad spark but that wouldnt make sense if it occasionaly does it only sometimes. which made me eliminate fuel pump and spark plugs
- the sputter consists of massive loss of power even sometimes to the point to where no matter how much pedal u lay down it wont even make a noise until u floor the pedal and then it will kick and be totally fine...until you let off the gas again. i mean litereally no sound from the engine not even an attempt at noise( i have a loud muffler so u can always tell) sometimes when u let it try to recover it lets a huge backfire sometimes a couple before it starts moving again.
- somedays it will rough idle weather its warmed up or just cold. and it will sit there and fight with its rpm. starts to idle fine. starts sputter and dipping to low then revzs it self up,. comes to an idle and a few seconds after it will begin to start dipping over and over until it finally will just sputter and die. but it will start right back up everytime. its more of an annoying nuesence then anything

if anyone can help me at all on determining what could be causing this issue without sinking tons of money ( i dont have) to replace parts till i finally find the right one

my opinion.. its either of the following
-Mass airflow sensor
- distributer cap
-loose wire
- oxygen sensor
those are the only outcomes i see any ideas please please let me know i love this truck all to much to want to part ways and give up

Inspect your vacuum lines and your EGR valve. Sounds like your EGR valve is sticking which causes the issues your have mentioned above.

Clean out your EGR valve with Carb cleaner and best to remove it to clean and inspect for proper operation of the Valve. If its damaged or to dirty, best to replace it with a new one.

Good luck and keep us posted.

Molson02536

 

[Abstrakt123]

Ok so i have another symptom i forgot to mention. the truck if not in gear ( its a 5 speed Manual) will run fine and i can max the rpms know problem unless i leave it sitting at an idle will it do the idle problem but as soon as i give it gas it will run utterly flawless until i put it in gear and give it strain. also there is a sound it makes when i first start it each day that almost sounds like a belt slipping but not squeling at all its a very weird sound. im gonna youtube the noise it makes and the symptom tomorror and post a link to the youtube video for further information and help . ty so much for the replys everyone

im goimng to be taking off the EGR Valve tomorrow and Carb Cleaning and swabbing it to check that and i was also told it could be my distributer router thing im gonna replace that anyway since its a cheap part and i have put this truck through alot of pulling and some big mud =)

 

[Abstrakt123]

AT THIS TIME I HAVE GOT THE EGR VALVE out of the truck and it is riddled with black shit. been spraying it for an hour to loosen it up and swab as much as i can out. the valve is very ruff but its getting better at being less hard to push. but its very slow when it moves into normal position after being pushed down

 

[wrenchist]

If you had EGR flow at idle the engine would idle poorly. TBI is a low pressure system. Even 1 psi below spec would cause the symptoms you describe.

 

[Abstrakt123]

ok so i cleaned my EGR valve and replaced the distributor cap and rotor and symptoms persist.. im so lost on what to try next