Lambda ECU

[Bitsyncmaster]

Our Lambda ECU reads the stock narrow band O2 sensor voltage and adjusts the mixture via changes made to the frequency valve. The problem with the stock ECU is that it does not wait long enough for the last adjustment it made to take affect and makes another adjustment. Hence the mixture swings in an oscillation from rich to lean and lean to rich continually. This changing mixture is the most common cause of idle hunt. My ECU delays making another mixture adjustment until the last adjustment has resulted in the O2 sensor reading the current mixture.

When setting your dwell reading to the book value of 40 degrees (4 cylinder scale), your not adjusting the mixture but your centering the lambda system. Your mixture is fixed at 14.7 AFR using a narrow band O2 sensor. It?s really not that critical to perfectly center that dwell reading. As long as the dwell does not hit the max or min value, your mixture is 14.7 AFR. Having it close to center helps when the mixture changes due to altitude and other engine variations.

I built my REV B ECU a few years ago and have sold a few of those units. My car did idle hunt right after the lambda system went active (about 3 minuets after cold start). It would idle hunt for a few minuets after that and then would idle fine. That REV B ECU fixed (no idle hunt) that problem. My customers have also stated ?never an idle hunt?. Now a sticky idle motor or mis adjustment with the constant idle system can also cause idle hunt. The REV B ECU is a plug and play upgrade. Your dwell adjustment will not change if your stock ECU was working normally.

A lot of my customers want to keep their stock lambda or idle ECUs. This was not a problem when I could get those ECUs on Ebay for a decent price. Now it?s rare to see them offered. So I made my REV D lambda ECU which eliminates the need to return your stock unit for update. However it requires you to attach the 7 wires to my connector. Note the blue sensor wire was a shielded wire so it has two connections. I?m sure that shield is not needed. That wire runs along side the metal plate so any electrical noise will not be present at the sensor wire. I?m just going to run the single sensor wire (from the sensor to the plug in the wheel well, it?s just one normal wire). I did provide a pin for that shield wire anyway. Also my REV D has an extra pin that can drive a remote LED.

If you have any questions about our lambda system, ask me now that I?ve got it all fresh in my mind just completing that new ECU.

[WHO1DMC]

Forgive me if you've already did this.
I see a bunch of volvo ECUs for sale. The ones were I can see the pins are the same configuration. For around $15 to $30.

Are those not usable for some reason or is it the price?


Just being curious.
Dave B.

[mike123]

The DeLorean Houston parts website says the failure rate of these is very low. I am curious why that is the case, when also thinking of the automatic governor and the door lock module which both seem to have very high failure rates. Anyways just curious.

[FABombjoy]

The DeLorean Houston parts website says the failure rate of these is very low. I am curious why that is the case, when also thinking of the automatic governor and the door lock module which both seem to have very high failure rates. Anyways just curious.

Lambda box is all solid state and lives in a cushy private office. The components selected for the design don't really fail with age.

The governor and DLM both have aluminum electrolytic capacitors which age with time / heat. Probably other sketchy design issues. I've never looked at the auto trans governor board.

DLM has crappy relays.
Governor is installed in a pretty hostile environment.

[Bitsyncmaster]

Yes the Volvo lambda ECUs will work with my circuit board and then function in our cars. The lambda ECUs seem to never fail. My update is just to help or cure idle hunt. Also an LED to let you know it's working or not.

[mike123]

Thanks, makes sense to me. I have read about the faulty capacitors and thought that might be the case, so I am learning!

[Bitsyncmaster]

The new mini Lambda ECU is installed and running great. The installation even fixed a little misfire I had but this has nothing to do with the lambda. What I think is I connected the 3 black ground wires different. So that probably stopped a noise the ignition ECU was getting. Our stock harness's will all be different since the layout (what wires run beside other wires) is not controlled.

I'm very happy with the metal work design. However still undecided if I will mass produce these because of the metal work required. Anyway I completed 3 units because I had 3 circuit boards on my first order. If you want to buy one, PM me for more info.

The major reason for my lambda ECU was to reduce or eliminate idle hunting. The mini unit was done to not require a core, make more space in the cubby and reduce heat in the cubby for owner installing an audio amp and or speaker.

Stock ECU power at 13.5 volts is 51.2 ma. My mini is 1.26 ma.
Stock ECU weight with connector is 30.4 oz. My mini is 6.6 oz.

I have not driven on the road yet but also convinced you don't need that shielded wire on the O2 sensor signal.

[mike123]

Have you ever used SendCutSend for the metal pieces? That could potentially cut down on the metal work you needed to do for these.

[Bitsyncmaster]

Have you ever used SendCutSend for the metal pieces? That could potentially cut down on the metal work you needed to do for these.

I will look into it.

[mike123]

If you want to post or send more pictures, I am happy to give my two cents as well l. I have used them in the past for a lot of time machine stuff. They are great at cutting metal pieces and holes, especially for small parts of this size and especially if you order a handful at one time. If you require bending, that has become expensive with them and they have a lot of rules about how they can and cannot bend the metal.