This morning as I was driving my 1990 3VZe A340H (currently 147xxx miles) and I lost all power, again. This time, after getting it home, I ran the codes and I have four present. As the title states, those are what are present. (52 is present because sensor has no male connector in harness. PO cut out and "hard wired" a crappy wire in. Have not fixed yet)

Little back story: At cold start the idle is fine. Little low (IMO) around 1100-1200. After around 5 miles or a thorough warm up it idles very roughly and have to assist. Between 35 and 40 MPH the truck will "surge" (constantly losing and gaining power repeatedly). I also went through and replaced a ton of parts on it as I have a previous thread regarding. Will try to link in once I figure out how.

Code 12- Engine Speed Sensor- Circuit
I am not too familiar with this code or what would cause this issue to arise. Most certainly seeking help in this department.

Code 41- TPS
Brand new as of two weeks ago.

Code 42- Vehicle Speed Sensor VSS-
I believe this code was present when I had issues with injector wires last time.

Code 52- KS
Known cause as to presence.

I am starting to learn that a lot of the issues I have had are due to old wires which have previously been uncovered and have melted through insulation and ground out or have become corroded and disconnect the circuit. What can you expect with something that is 28 years old?

 

https://www.yotatech.com/forums/f116/shorted-battery-after-rebuild-will-not-start-304627/

 

I had the exact thing happen to my 3vze pickup, you need to replace the whole gauge cluster. My truck would start "surging" or cutting in and out around 30-50 mph. It was the oddest thing and it threw code 42 if I remember the VSS code. I replaced my cluster and it stopped having that problem.

 

this whole gauge cluster is what you need to replace. they are usually on ebay for not too bad a price, pretty simple replacement just have to take apart some of the dash around it carefully, some screws bolts, and unplug, replug the new cluster.

 

Yoti808 has the combination meter ("cluster") that goes with a cable speedometer. Mine ('94) has the electronic speedometer; I can't tell you which models or years have that.

The cable speedometer has VSS1 inside the cluster (just a reed switch.) The electronic speedometer has a Hall-effect sensor mounted into the back of the transfer case as VSS1.

Just figure out which one you have. From the back of the transfer case, you either have a speedometer cable, or just wires.