Engine sputters unless....

[schlob27]

This is driving me nuts.

My 2000 GMC Jimmy 4.3 2 door, James as we call him, has been sputtering for about 6 months now and I have run out of ideas as to why. Its not all of the time but at least 75%.

I have replaced the distributor, rotor cap, spark plugs, serp belt, fuel pump, temp control sensor, thermostat, fuel filter, and crank shaft sensor (both about a about a year ago), and flushed the radiator while putting in the green paper stuff to seal the head gasket.

Also the heat does not work and it seems that its blowing into the engine compartment and not into the dash. The vent actuator works.

So driving along today shaking like a leaf on a tree, I turn on the A/C from the off position and by golly James gets his sh*t together and start driving normal. I scratch my head and turn off the A/C and he starts sputtering again.

I am happy for the most part but getting chilly so I move the air from cold to in between cold and hot, in the middle of the temp thing. He starts whimpering a little and the timing is off but not too terrible. Turn the A/C back to full cold and he is running fine.

So as I am typing this out I start thinking, is it the serp or A/C belt?

Hell, I don't know and need some help.

 

[Molson02536]

This is driving me nuts.

My 2000 GMC Jimmy 4.3 2 door, James as we call him, has been sputtering for about 6 months now and I have run out of ideas as to why. Its not all of the time but at least 75%.

I have replaced the distributor, rotor cap, spark plugs, serp belt, fuel pump, temp control sensor, thermostat, fuel filter, and crank shaft sensor (both about a about a year ago), and flushed the radiator while putting in the green paper stuff to seal the head gasket.

Also the heat does not work and it seems that its blowing into the engine compartment and not into the dash. The vent actuator works.

So driving along today shaking like a leaf on a tree, I turn on the A/C from the off position and by golly James gets his sh*t together and start driving normal. I scratch my head and turn off the A/C and he starts sputtering again.

I am happy for the most part but getting chilly so I move the air from cold to in between cold and hot, in the middle of the temp thing. He starts whimpering a little and the timing is off but not too terrible. Turn the A/C back to full cold and he is running fine.

So as I am typing this out I start thinking, is it the serp or A/C belt?

Hell, I don't know and need some help.

Sounds like one of your vacuum lines that is connected to your vent selection switch has gone bad or the switch it self. The switch uses the the vacuum from the engine to control your vents and AC switch.

Start with the simple and inspect your vacuum lines that connect to your switch and replace any damaged parts. Also cleaning your throttle body and giving your engine a http://seafoamsales.com/vacuum-line-method-with-sea-foam/ treatment would not hurt also.

Good luck and keep us posted.

Molson02536

 

[schlob27]

Well thank you for the reply. I was the Distributor cap/rotor, replaced it with the AC Delco and we are really moving now.

On a side note, when I returned from the store I was screwing around with the dist cap my arm hit the return line of the heater coil. I pulled away fast like it would be hot and it was not... I pull both lines and hooked a hose up and sploosh, he must have had bad Chinese...

Now my heat works as well as the other hvac stuff. Read some places that the Dex-crap can build up in spots and cause a slow down or blockage.