Yes, I'm a newbie, been trolling on here for a while, just now registered. Searched for countless hours using forums and google, and I'm exhausted after trying to fix this truck.

Here is the background and I'll get on with the problems.

78 K30 Frame and Running gear, 454/TH400/205
88 S10 Cab,

My dad bought the truck a year a go to wheel while we dovetail, bob, shorten, and turn his 84 suburban on 1-tons into an 84 Avalanche. When we bought the truck it had a street avenger carb that someone had attempted to convert into a truck avenger. Truck ran good on flat ground, but sucked in the hills with fuel spilling out of vent tube into the venture. Truck would run rich on full throttle and very lean on part throttle. Ditched the carb, and bought parts to swap to fuel injection.

Howell Harness for 95 C3500HD 7.4L, and Prom to remove VSS and EGR functions
95 ECM, 16197427, BHMH Bin
95 GM OEM 7.4L Throttle Body

We installed the harness and all sensors. ( IAC, MAP, Heated O2, TPS, CTS). Running a factory style GM HEI....

Bottom line is, the truck runs super rich, and Howell has not been very helpful.

Using a Volt meter, as well as a borrowed OBD1 Scanner, we have checked all the sensors and everything is working correctly. Vacuum is steady at idle at 18.5-19". Idles choppy at 750-900 rpms. Small cam in 454, not too much overlap, considering idle vacuum. No other mechanical problems or vacuum leaks. Checked and rechecked all the typical easy fixes, and checked for leaks using propane, and found nothing.

The Heated O2 Sensor is in the Pass side header, just downstream of the collector, and measures around .89V at idle, pointing out the Rich Condition.
The Map Sensor voltage is between 1.5-1.8V at idle, again 18.5-19".
The Tps sensor was reading 1-2% at idle,
The IAC works and could been seen stepping in/out on the borrowed scanner.
The Base ignition timing is set at 12 degrees advanced with the connect closed (jumping out terminals)
The CTS is reading 298 ohms at 190 degrees, and 617 ohms at 150 degrees. Whether the engine is cold or warm, no change in AFR.

Fuel Pressure is 30psi, and the regulator works. From Howell -> 1995 HD 7.4 models used a higher 30psi fuel pressure to get needed flow from injectors. At first startup we had 15psi tbi pump and it definitely ran worse. Swapped to e2000 pump. Confirmed Regulator is working by pinching off return line and pressure runs up quickly. All new fuel lines so I doubt a blocked return line with the confirmed regulator operation.

As you crank up the truck the O2 sensor voltage starts at .45 volts and just creeps upward to .89-.9 the longer it runs. The exhaust will burn your eyes and is obviously rich, as well as plug fouling doesn't take too long. Tried 3 different heat range plugs with no effect.

Once engine is warm, when you drop it in gear, truck will stumble and stalls 50% of the time.

Replaced O2 sensor, TPS, MAP, and CTS and makes no difference. Only difference is truck runs better with the O2 sensor unplugged.

This brings me to building an ALDL cable per instructions on several forums. Can run it on either direct serial port or Serial to usb converter. Verified cable operation by plugging it in to 89 4.3L s10 blazer, and had all functions of WINALDL and Freescan. I have downloaded tunerproRT, Winaldl, and Freescan and nothing will communicate with the 95 ECM. The goal is to further diagnose the terrible rich condition by using TunerproRT as a glorified scan tool, and decide how to fix the truck, and get it to run better.

I downloaded the BMHM bin file, as well as the $0D Mask, and the $31 mask from this site.
Pretty sure I have done necessary steps with TunerPRORT but not positive because I have no communication with 95 ECM.

Also, when I try to open bmhm bin file, tunerprort says unable to open.

First off, not sure If I am doing correct things in the correct order with TunerproRT, and not sure if I installed the BIN file and Mask correctly. I'm not fluent with TunerproRT yet, but tested the ALDL cable using WINaldl on the 89 4.3, to rule out that it is a cable problem.

Any Ideas on why it is running rich? and Any advice appreciated on how to use TunerproRT with the masks for my ECM.

Thanks,
Scott.