Well here is the update to to the update!! I borrowed an Innova 3140 Scanner ( May have to get me one these reads a lot of makes and models although doesn't do ABS but I hear the 3160 does ) Anyway I only had one code it was P0123 Throttle Position Sensor A circuit high input. Ok I was able to clear and erase the code however I am expecting the CEL to come back on in time because when I took the truck for a drive it was back to its rough idle, lack of power and almost wanting to stall phase. I am thinking I want to just replace the TPS ( 33.99 and 2 yr warranty at Autozone ) it has been in the truck for over 100k miles and 12 years but this will be the thrid sensor. I already replaced the IAC and CKS ( Had high ohm value so I thought it was the problem ) so I don't want to keep throwing parts at this in the hopes of fixing it. So what do guys think??? Ha getting better with all the acronyms too LOL!!! Yaya doesn't take much to keep me amused LOL...

 

If the PCM is whining about it... Test it. Got a vom? Analog would be preferred..... Measure the resistance across the terminals as you slowly open the throttle. The needle shoud move smoothly across the range. If it jumps around, sensor is toast.

Also, measure signal voltage from the PCM. Should be five volts. (digital meter is best for this application.) If it isn't, find out why.

 

As I opened the throttle meter read from .987 to 4.1 K in a smooth rise I checked it multiple times. Also did a live data test on the TPS with the scan tool it measured 13.7 to 75.3% in a smooth rise as well as I depressed the gas pedal. Measured voltage purple (Supply) to black (Ground) key on cable disconnected 5.17 Vdc. Voltage connected orange (Signal) to black (Ground) key on .7 to 3.8 Vdc as I opened the throttle. Still was running rough as hell at an idle. I am still hearing the hiss coming from the TB not sure if this is normal or what. IAC is fairly new, vac line to the TB looks good I'm at a loss here but still plugging away... Atleast she is running again!!!

 

Sounds like the TPS is fine, and doing what it is supposed to. Wonder why the PCM is whining about it.......

Hissing is the IAC. What you hear is bypass air. Nice convoluted path, so, it tends to be a bit noisey.

Can your scanner do an IAC test? How old are your O2 sensors?

 

Couldn't find a test on the scanner for the IAC but I did pull it and both coils read about the same approximately 52 to 53 ohms. As for the O2 sensors they are as old as the truck (12 years and 100K miles). Only thing I had replaced before this was the fuel pump at about 60K miles. Well other than normal maintance stuff like oil, filters and plugs...

 

have you checked for vacuum leaks around the base of the throttle body, etc?

 

Yes actually I have but those can be rather hard to isolate but I haven't given up yet!!!

 

LATEST UPDATE!!! Truck starts everytime now but we are back to the original problem that I was going to clean the injectors for. Truck had a rough idle almost to the point of stalling after initial cold startup and then any startup there after warm or not. Any way been playing with new Innova 3140 scan tool checking anything that was supported. Started monitoring O2 sensors like you guys suggested. It seems the B1 S1 (PreCat) is bad only fluctuates from 80 to 200 mv. Its staying in a lean mixture therefore leading to my rough idle. The B1 S2 sensor is sitting at about 200 mv. I checked our newer 3rd gen and the fact that it sits seems to be a normal condition. On the 3rd S1 in jumped from 100 to 800 mv and the S2 stayed at about 600 or 700 I don't remember exactly. So looks like I'm off to buy at least one O2 sensor. Brand suggestions for best reliability???? Denso? Bosch? NTK? Walker? Best place to purchase??? Thanks

I see light at the end of the tunnel .... LOL

 

Final Update - Ok I know I should have done this earlier so the thread has a fix but I've been running tests to make sure all is good and checking mileage so sorry guys to be so late. Any way rebuilt PCM from Auto Computer Exchange in Florida fixed my starting issues. ( Dealt with a guy named Rudy and everything went smooth ) Had my Kelsey Hayes 325 ABS Module rebuilt by Module Masters and they were one of the best companies I have ever dealt with. As for the rough idle I replaced the Pre Cat O2 with Standard Motor Products Part # SG1816 18 inch wire. I actually lost a 1 MPG since truck isn't running lean anymore but now have increased power and a smooth idle. I want to thank everyone that took the time to help!!! You guys are awesome especially Cmckenna and Hey You... Time to start adding mods now LOL