Bonjour all, I''ve purchased a 1985 412i from Seattle. The car has been delivery new in Brussel, then exported to California the same year. The car is now in France and step by step I check this car who was sleeping from approx 10 years. Equipped with lambda sensors installed on the exhausts my question is: can I remove them without risk ? Thank you for your help. Hervé, France Sorry for my poor english.
(Assuming it's the stock 412 K-Jet systems with the typical US modification to add a crude Lambda function to the control pressure) Yes, but you'd also best remove the added frequency valve(s) (also sometimes called a metering valve) and the added associated plumbing (if it/they hasn't been removed already). If you can post a photo of the engine bay, it should show whether the frequency valve(s) is(are) still there or not. If you have two Lambda sensors, you should also have two added injection ECUs (or a special two-channel added ECU). Of course, it's always possible that Lambda (Oxygen) Sensors were add to the exhaust just as eye-candy to fool a US inspector and aren't really doing anything
Dear Steve, First thank you for your help. this is the engine of the beast. Image Unavailable, Please Login
Here is a pic of the frequency valve, and other components I removed from my 1985 400i. The diagram shows the other components used in a typical US emissions update, if you have the oxygen/lambda sensors then you probably have the other parts also. I removed all of mine as the system was already not working and not original to the car. Gary Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
This jpeg shows what I think are the added frequency valves: Image Unavailable, Please Login They are a different style than what Part Time posted. One fuel line from each should go to a stacked set of banjo fittings on its warm-up regulator -- can you post a closer picture of each and its warm-up regulator showing these connecting lines? The other fuel line from each frequency valve would go to one of the fuel distributors. One difference can be that Part Time's system was already disabled, and since the air-fuel ratios would've been tweaked after the disabling, he could remove it with no change to the engine operation. If your Lambda system is actually working now, and you remove it, you would (probably) need to readjust the air-fuel ratios.. One thing you can do just touch the frequency valves when the engine is running to feel if they are vibrating (if they are, your Lambda system is working). Alternatively, if the electric wiring going to these frequency valves can be unplugged, you could try unplugging them with the engine running to see if the engine operation changes.
Hi Gary and Steve, Please see pictures . In fact the engine work not bad but I want to remove the catalytic converters, and replace by straight tubes. I confirm the car is equipped with the white box under the dash board. Thank you Hervé Image Unavailable, Please Login Image Unavailable, Please Login Image Unavailable, Please Login
Need to correct myself -- this jpeg shows an added frequency valve: Image Unavailable, Please Login Not sure what those two pneumatic gizmos with the yellow end caps are, but the way they are plumbed looks sort of odd. Some questions: 1. Do you have one or two Lambda (Oxygen) Sensors? 2. Do you have one or two added frequency valves? 3. Do you have one or two added "white box(es)"? Other 400i/412 that have this modification typically only had one of each item as the control pressures from the two WURs are connected together (so there is only one average control pressure even though there are two WURs).
Can't say that I understand how two Lambda sensor signals could be used to control a single frequency valve. On the schematic that Gary posted, it only shows one Lambda sensor input signal. If you do remove the system, would be interested to learn if they are really both hooked up to the white box . Might be that one is used by the white box, and the other is just used to aid in setting the air-fuel mixture - just a thought... Couple more questions: 4. Does the frequency valve vibrate/buzz when the engine is running at warm idle? 5. If you unplug the frequency valve when the engine is warm iding, does the engine warm idling behavior change at all?
Hi Steve 1. when engine warm idle, disconnecting the frequency valve change nothing. 2.at my opinion the frequency valve do not vibrate. Thank you
Philippe....I also removed my cats for a different reason, (the left cat convertor had overheated and broke apart, plugging the tail-pipe) see my pic, my sensors were in the same position as yours. And here is what I used to plug the sensor hole, which is just forward of where the cat was cut off, you can see the new weld in the pic above. Gary Image Unavailable, Please Login Image Unavailable, Please Login
Philippe, just asking...what is the last 5 of your VIN #....we both have 1985 cars, mine is 55027.. Gary
Hi Gary, In fact I do not like these 33 years old catalytics exhaust probably dirty inside. I will remove them . The size of the plug is metric(18 mm) and easy to find here in France. Thank you for your help Herve
I ran the emissions research and design portion of a Federal Emissions Laboratory for almost 5 years in the early 1980s, and can tell you quite a bit about what you have here...the integrator circuit was made by Dave Johnson(I know his son well, and he lives right here not a mile from where I sit, by sheer coincidence!), and assuming that this was a legitimate "modify and test" car(which is likely from the pictures posted), the reality was that those "lambda" boxes were quite short lived...we used to joke that they were only as long lived as was the test), the LA-55 FTP.... The catalyst in this era was loaded 4, 4, 5 grams per cubic foot, in what was called the "317" cat....named for a commercially available unit manufactured by: Zuena-Starker AG, in WG, under license from the patent holders(my fathers best friend at The Office of Naval Intelligence at MIT invented it, and is the original patent holder for "finely particulated", colloidal platinum, palladium and rhodium TWC-as a side note.) We spent MANY years in Federal court on patent infringement violations by almost every manufacturer in the world...I digress... That said, there OUGHT to be two of these...there ALSO should be 2(two) gold colored ballasts that have lots of heat sink fins on them and which will be wired into the harnesses as well-1 for each bank. The trick with these Ferraris(BBi and early TSs as well)was: the bench measuring-and matching-of the decay rates for the bi-metallic springs in the control pressure regulators-as the simultaneous decay rate was the most critical factor in passing the cold bag-once the cats lite, its game over-the car draws "flat lines". Its the first 45 seconds of the test-up and over the "big hill"-which is where you win or lose the game in this test,in MY experience(over a dozen small volume certificates of manufacture-the same proto-call which Ferrari and most other "small volume manufacturers of Passenger cars and Light duty Vehicles below GVW of 7500 Lbs. certifies their cars for sale here in the US.and NA markets. The evaporative SHED test is another story for another day....and NOBODY will call you on this-good or bad... If you want to run "open loop," its a rather simple process of deletion and then re-setting your control pressures up properly, the base idle, and idle CO.. Also, a nanometer to set left bank/right bank balance at idle,and cracked, and at 2500RPM. The CIS/Bosch ECU will take care of the rest-which isn't much....the 32 pin prom chip MIGHT use 18%of its capacity for every model, market, in the world which this car was intended for, maybe... Any additional questions, drop a PM ciao
