Alright so I took the lady out to dinner and as I left the restaurant it was shuddering and kept dying so I figured I was out of gas even though I knew I couldn't be. I got to speedway and it took 6 gallons. It would run but die if you hit the gas or put it in gear.
A few friends came by and we started trouble shooting.
Fuel pressure at 60psi, fuel pump was obviously working strong, new fuel filter also. A SES light finally came on and we pulled code Po122 off of it and no other code. So of course tps came to mind and my buddy ran back to his house and picked one up. ( he is a s10 nut and is building a nitrous motor so he has so many parts laying around) We tried the new tps which worked when he took it off his truck and still nothing. We used the scan tool of his and with the truck off and ign on position we put the pedal to the floor and got 23% throttle when it should be more like 96%. Next I took a voltage tester and checked the tps and it was very inconstant from 1.3 to 300. My friend had a guy who has the same program mechanics use to search for common issues where you enter the SES code and get common errors. It came up with short by the driveshaft, shorted wire on top of transfer case and the last one was something like SVAT in the kick panel.
I ended up having to have the blazer hauled home on a car trailer by the girlfriend’s father. I was able to drive it up the car trailer in 4 low by letting it just idle. As soon as you even slowly touch the gas it chokes out. I had to restart that truck around 100 times last night and I have a feeling my battery is pissed at me but luckily I have a new battery with a 3 year warranty.
I thought I would ask you guys for opinions first because this forum is very helpful. I'm just going to have to park it till next weekend and drive my company truck to work and class.
Thanks guys
-Brian

 

I would test the voltage to the sensor from the PCM. It should be 5V.

Here is the diagnostic sheet for the code:
P0122 - Throttle Position Sensor Circuit Low Voltage

 

I read that post you made already.
It should be 5v at idle and .2-.4 at WOT
I'm getting such off the wall readings I would only think I would have a wire rubbed through somewhere. I checked it out this morning with a creeper and a couple spotlights and found nothing. Next weekend ill take the looms loose and check it out especially on the crossmember and about the transfercase.
A side note that when I had that obd2 reader the tps was showing up as .13 at idle.
Also my tps does not seem to spring back after you load it but my friends replacement he gave me does. That might not mean mine was bad in the first place but it was odd.
Thanks for the imput Swartkk.

 

No, you will have a 5V reference from the PCM powering the sensor. Your output should be around 0.5V at idle and around 4.5V at WOT.

 

I was just reading that and I was going to ask. I suppose I tested the output then by testing the plug of the tps. How do I test the PCM 5v?

 

Pull the plug. With the key on, probe the +5V reference wire (terminal A - gray wire). While you are there, test for ground at the sensor as well (terminal B - black wire). The ground is shared with the ECT (engine coolant temp) sensor located in the driver side cylinder head.

 

Alright thanks. I will try that.
Can I do all this without a scan tool?

 

A regular multimeter can be used to test this.

 

I have one more question for you sir. I checked all my connections, I took apart most of the looms and looked for shorts, and lastly I checked with the multimeter and I'm not sure I did this right but my black and grey wire were showing up as .30 and my blue wire was 1.94( cant remember for sure on that last one). I started checking my grounds and I shook the ground thats on the firewall on the passengers side. I started up the truck and everything ran fine. I know the ground must be still loose though. Its tight on top. I wanted to ask you where the ground goes to because I could not trace it down. I know it runs down the backside of the motor but when I look underneath I cant find it.
Thank you,
-Brian

 

The ground goes back to the ecm to complete the reference voltage circuit