wow, i sure would appreciate that you could check out the dist. from that 96 Astro that you have. this way we will all know if it also has magnets in it too like the earlier years. maybe you can also put a peiece of metal on the shaft or reluctor to see if it sticks to it magnetly too.
yes, i have the plastic distibutor that has a permantly fixed hold down tab as part of the dist. body. and the reluctor looks like the 96 type. and it also has that hall effect sensor in it....
please let me know what you find out.

also on a different note, today i took off that plastic cover that says "Vortec" thats bolted to the top of the intake plumen and under that there is a round black thing under it thats held in with 2 screws and when i pass over it i smelled gas....why? is that the injector? or part of it?

 

That is the MTV (manifold tuning valve) can be removed and you can look down inside the plenum to check for a fuel leak..

 

so wait, this manifold tuning valve can be removed within minutes? and is there a gasket under it that needs to be replaced if i do remove it? i would like to remove it to see if theres any fuel leaking under it but then i want to put it back just incase i need to drive the truck. what else should i look for while the valve is off? also, whats the purpose of a manifold tuning valve? thanks much

 

I had a problem with timing jumping around on an old '87. Turned out the ground for the ECU was loose (it was on the back of the drivers side head, below the windshield wiper motor). Try to check the timing when the motors cold and in open loop mode - my truck ran ok when cold but would be undriveable once it went into closed loop mode. In my limited experience, those pickups in the distributors either work or they don't.

 

I havea Vin "W" 1995 4.3 in my BLazer, I get some timing "jump", but I only get 1-3 degrees of movement on mine, but i have the side post distributor, I don't know what style you have ..

 

Hi Biohazed,

i have a side post distributor too. it looks like a crab. the spark plug wires hook from the side. does your timing have a minus symbol in front of the timing number while you were scaning it? aside from my timing jumping like crazy, it also reads in the negative zone, why?

Hi cks20,

how many ground wires should i have? maybe i should hook up a new ground wire from the battery to various places on the motor to see if it runs better, what you think? i did check the timing when the motor was cold in the morning and the timing was a little bit more steady but it still read in the negative zone. whay is it in the negative zone? i advanced the distributor 1 tooth but it didnt not want to run. also where is my ECU on my 95 S10? also what would your truck exactly do after it warmed up and was in closed lop mode? thanks so much