I have an 89 V-6 Z Vin.

The idle while in drive is sloppy. It wants to stall and sometimes does but usually, I can feel or hear the engine correct whatever is wrong.

I have replaced vacum lines.
Cleaned EGR.
New Plugs/Wires.
Oil Change.
Replaced O2 Sensor.
Replaced Fuel Filter/PCV Valve.
Sea Foamed it.

I think it's firing on all cylinders. It seems like something in the fuel system. I have never changed a pump before and I'm not sure
I even have to now. I can hear the pump so, it shouldn't be that right?
Anything else I should look into. I'm not a mechanic by any means. What is this spyder thing I keep reading about?
It stinks because the truck starts right up and runs ok but at traffic lights it wants to stall on me.
Also, sometimes when I park it stalls or comes really close and the window dosen't want to go up? It seems like the truck is possesed by some kind of power demon that only messes with me after I feel that the truck is running better.
Is GM playing some kind of horrible joke on me or something?
Should I just light this thing on fire to please the Blazer Gods or is there something simple and inepensive (a paradox) that I'm overlooking?
Thanks for any help/suggestions!
May you all find peace with your Blazers!

 

You have a Vin Z so your engine doesn't have a spider.

You say you replaced the plugs & wires, but did you check the cap & rotor?

 

Ok no spyder.

Yes I checked cap and rotor. No depostis or anything. Sanded down the contacts a bit anyway.
I'm pretty sure it's a fuel problem and not a spark thing though....

 

Check your fuel pressure if possible. The pump may be working but the Fuel Pressure Regulator may not be adjusted correctly. I recently installed an adjustable FPR in my 89 and my stock regulator was around 6 psi which is below spec. I bellieve GM Spec for the 4.3 TBI Vin Z is 9-11 psi. I now have mine adjusted to 11 psi and what a world of difference in the Idle. I also installed a inline Fuel Pressure Gage so I can always check my pressure. You could also have a faulty Idle Air Control valve and do you know if the EGR is making a good seal?

 

Thanks. Any links on changing out a FPR ?
The Chiltons manual isn't real clear.
Can I adjust mine if it's not damaged?
My EGR has a good seal. I put a brand new gasket on it when I took it of for cleaning.

 

nevermind found it in Chiltons but.....
in the manual it says the meter cover and the regulator must be changed as an entire unit but, all of the part stores sell only the diaphram?

 

Most TBI rebuild kits include a spring and or a diagphram. However there are companies that sell an adjustable FPR. I bought mine from CFM Technologies. It was easy to install. The adjustment was a bit hard because the adjusting screw was hard to get at once installed. I ended up adjusting it offthe TBI installing it then checking the Fuel Pressure. Kept repeating the process of installing/Checking/Removing/adjusting/installing again untill i got the pressure within spec. Here is a link to CFM Tec. I also searched ebay and found adjustable pressure regulators for sale. At the same time i installed CFM tee and fuel pressure gage.

http://www.cfm-tech.com/gm_tbi_fuel_pressure.htm