Lil'John

In my old Land Cruiser, I've got an 2004 LQ4 mated to an NV4500 mated to a Land Cruiser transfercase.

I'm using a "custom" VSS made from a 2004 4L80e speed sensor and a 40 tooth reluctor ring.

My issue is the signal at the PCM jumps a lot. At a steady speed it will go from dead on to 20mph slow to 15 mph fast.

So I've got three placed I can look at:

1. VSS sensor spaced too far from the reluctor ring. Since it is a custom unit and the fab was done offsite away from the vehicle, it could be a little bit off.
2. Bad Vss sensor. While I bought it new and it has maybe 300 total hours on it, I could be talked into it being bad.
3. Bad wiring. It was a very long run from the PCM to the VSS. I did splice together to stock twisted pairs to make the run and kept the untwisted part down to about 1/2" long.

So the first question is whether a VSS sensor that is too far from a reluctor ring would produce erratic results.

The second question is whether a bad VSS sensor would produce a similar problem.

Thanks in advance.

LS1MCSS

iTrader: (18)

Try to figure out how far the VSS is from the reluctor ring. If possible, try to get it about 1/16" from the ring. If it still jumps, check your splices in the wiring. I hope you used solder and heat shrink tubing on the splices. I don't think the distance would have that much affect.

ls1nova71

iTrader: (4)

Do you have anything tapped into the VSS wires? I had a speedo tapped directly into my VSS wires per Autometer"s instructions and it caused the MPH to be erratic. Just a thought.

Lil'John

On the VSS spacing, I had heard the number was somewhere around .04". I will try to double check but when I had it created, I believe that is what I told my machinist.

My splices definitely are soldered and shrink tubed. They are also high in the engine bay ~2-3ft away from the PCM.

At one point, I did have the speedo tapped in(at the above mentioned splice) but I couldn't tune the speedo down enough so I converted to use the PCM driver.