Inside the Lambda Counter

[kobachi]

My speedometer failed recently. I jacked the car up earlier today and tested both speedo cables with a drill and they appear to be fine. At this point it's either the "dust shield" (hopefully) or a failed angle drive.

My "Lambda" service counter has always made a plastic whirring sound which has gotten worse over time and then ceased when my speedometer failed. I thought that perhaps this unit had failed, and took it out to take it apart and investigate. It turns out that the upper and lower speedometer cables are connected by a solid metal shaft. This means that even if one or more of the several plastic gearing components in the service counter fail, the speedometer drive should not be affected.

IMHO the service counter is an over-designed piece of wasteful engineering to begin with, and I've wanted to get rid of it for a while. ("A designer knows he has achieved perfection not when there is nothing left to add, but when there is nothing left to take away.") In order to avoid purchasing a $70 "long" speedometer cable -- given that my existing cables appear to be ok -- I removed most of the internal components of the service counter and then sealed it back up. This should allow me to continue to use the unit as an connecting anchor point for the two speedometer cables, while eliminating the whirring sound of the plastic gears which I found so irritating.

I haven't seen images of a disassembled service counter before, so I decided to upload some and post them here, in case anyone else might find them useful. I took these with my iPhone so I apologize if the lighting isn't so great.

DeLorean Lambda Service Counter Disassembled (http://imgur.com/a/sKEnn)

[jmpdmc]

A big +1 on this. I had symptoms that appeared to be an angle drive failure back in 2006 which turned out (after much testing) to be the lambda counter binding. Gutted the counter of gears and reconnected the cables. No problems due to the counter since.


Jeff

[Starglider]

The only good use of the lambda counter is as a convenient way to add the speed sensor for power steering (e.g. Ed's power steering kit). I've also tapped it to drive my digital speedo (I prefer a direct sensor to GPS).

[kobachi]

The only good use of the lambda counter is as a convenient way to add the speed sensor for power steering (e.g. Ed's power steering kit). I've also tapped it to drive my digital speedo (I prefer a direct sensor to GPS).

I was thinking of purchasing Ed's kit in the future -- does it depend on the Lambda counter, or does it replace it? (i.e. does it depend on the break between the two speedo cables?) I ask because it would appear I do need to replace my cables, if not my angle drive, and I was thinking of just eliminating the counter altogether.

[Starglider]

I was thinking of purchasing Ed's kit in the future -- does it depend on the Lambda counter, or does it replace it? (i.e. does it depend on the break between the two speedo cables?) I ask because it would appear I do need to replace my cables, if not my angle drive, and I was thinking of just eliminating the counter altogether.

Replaces it. The sensor is built out of an old lambda counter shell + modern magnetic pickup, so you might get a slight core discount on your old one. You can fit it elsewhere if you have a single long cable - which we had to do on mine because the Wooler Hodec cars have no lambda counter - but it's a lot more hassle than using the original mounting point.

[kobachi]

A big +1 on this. I had symptoms that appeared to be an angle drive failure back in 2006 which turned out (after much testing) to be the lambda counter binding. Gutted the counter of gears and reconnected the cables. No problems due to the counter since.

How did you manage to test this? The shaft in my lambda counter appears to either be slightly bent or perhaps doesn't sit completely straight in my counter. I'm too am not sure if my problem is a failing angle drive or binding caused by the counter. Did you do anything else besides remove the insides -- e.g. greasing the shaft?

[jmpdmc]

The DeLorean Mailing List over on the Yahoo Groups has a nice speedo diagnosis walk-thru in message #40155. You can unhook the lower cable, put a drill on it and see if the speedo moves. If it does, then something on the wheel side is the problem. If it doesn't move, you can then unhook the upper speedo cable, put a drill on that end and rule out the speedo head and upper cable. I think I remember the counter clicking in my car to tell me something was wrong with it. All I did was remove the gears inside the counter.


Jeff

[kobachi]

The DeLorean Mailing List over on the Yahoo Groups has a nice speedo diagnosis walk-thru in message #40155. You can unhook the lower cable, put a drill on it and see if the speedo moves. If it does, then something on the wheel side is the problem. If it doesn't move, you can then unhook the upper speedo cable, put a drill on that end and rule out the speedo head and upper cable. I think I remember the counter clicking in my car to tell me something was wrong with it. All I did was remove the gears inside the counter.

Oh, ok, thanks, this is exactly what I did. Unfortunately my dust cap is also stripped out so it's difficult to tell if I solved the problem or not -- and at $15/ea, it's a bit risky to slap it on and hope another one doesn't get bored out.