Jump to content
SAU Community

Recommended Posts

Is closed loop ....o2 feed and active changes?

And open loop means the loop is broken and or uses maps. Loaded maps being wot and high throttle maps tuned in the ecu like an idle map but for when the cars power is under load?

Google closed loop and open loop control systems. 

Get on YouTube if you still can't work out what an open/closed loop control system is. 

It is very clear you do not understand what each term means.

Regarding your 'load map', there are high load areas on the fuel and timing maps, I've never seen a separate map specifically for when the engine is on high load. I hope such a thing doesn't exist because it would be a pain to tune, constantly swapping between multiple maps.

While your googling, Google fuel map and have a look on the images, you'll see the maps cover the entire rpm and load range the engine operates in.

I was serious about the English as a second language question, do you speak another language?

  • Like 1
3 hours ago, Slap said:

Wide band gauge is delayed too much to save a bad leanout that is why it should be monitored by the ecu or other different automatic safegaurds.

So how would the ECU monitor the air to fuel ratio?

"Defining Open Loop and Closed Loop o2

Open loop is when the ECU is not referring to the o2 sensor for feedback. ... Closed loop is when the ECU does refer to the o2 sensor for feedback. Using the o2 sensor the ECU will modify its fuel table based on the readings the o2 sensor is seeing."

5 hours ago, Dose Pipe Sutututu said:

So how would the ECU monitor the air to fuel ratio?

Slap has invented the world's first mechanical air fuel ratio gauge. Think of the cost savings, never having to replace another sensor again

  • Haha 1
  • Confused 1

I may have invented load maps but ment load area of the map. Eg....

"Pulling a fifth-wheel camper up the Rocky Mountains at highway speed, for example, puts the engine under a huge load and requires a lot of energy. The ECU gets input from all of the sensors on vehicle speed, air intake, pressure, and temperature and plots a specific point on the imaginary graph. The computer is programmed to tell the fuel injectors what to do at that very point on the fuel map, and it sends out the appropriate message -- without any more input from the driver."

open loop and closed loop is well known i believe and maybe you should do some googling and maybe you will see where my terminology isnt correct. But its the jist.

46 minutes ago, Slap said:

Using the o2 sensor the ECU will modify its fuel table based on the readings the o2 sensor is seeing

That's not actually true. Was clearly written by someone with half an understanding. What really happens is that the ECU leaves the values in the fuel table alone and DOES NOT modify them. It may or may not use them as the base for the calculated fuel qty that it will then apply the feedback factor from the O2 reading, and also apply the long and short term fuel trims if and as they exist.

And how do I know? Well, the Functional Description documents that I have been writing recently for Burner Management Systems for a couple of different rotary kiln systems with fuel-air ratio control WORK IN EXACTLY THE SAME WAY. I even have a CO sensor in the kiln exhaust as a Safety Function.

The capitalised names above are capitalised for a reason. A Safety Function is such a serious thing that we use capitals when writing about it. A Functional Description is what is used by the system integrator and programmer to write the PLC code. All of this is covered by AS 3814 and AS/IEC 61511.

The words that are in all caps are just me shouting.

17 minutes ago, GTSBoy said:

That's not actually true. Was clearly written by someone with half an understanding. What really happens is that the ECU leaves the values in the fuel table alone and DOES NOT modify them. It may or may not use them as the base for the calculated fuel qty that it will then apply the feedback factor from the O2 reading, and also apply the long and short term fuel trims if and as they exist.

And how do I know? Well, the Functional Description documents that I have been writing recently for Burner Management Systems for a couple of different rotary kiln systems with fuel-air ratio control WORK IN EXACTLY THE SAME WAY. I even have a CO sensor in the kiln exhaust as a Safety Function.

The capitalised names above are capitalised for a reason. A Safety Function is such a serious thing that we use capitals when writing about it. A Functional Description is what is used by the system integrator and programmer to write the PLC code. All of this is covered by AS 3814 and AS/IEC 61511.

The words that are in all caps are just me shouting.

Is that not what it is saying in laymans terms, "as it MODIFIES" does not represent any one actual change, and is interpreted to myself as basic word usage so that it can be used to cover all different aspects and types of change and ecu's.

It doesn't modify shit, it applies a compensation/trim in either short term and/or long term trim.

The fuel table stays as is. However in aftermarket ECUs it stores the trims and you're able to apply it to the base table. This is the only time it "modifies" the fuel table.

  • Like 1
  • Haha 1

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • That is way more science than even I would use. I just eyeball it, not even accounting for the non-verticality of the tape measure when held on the lip and the centre at the same time. +/- 2mm is good enough for the girls I go out with.
    • So, before putting them in I need to understand the stock ride height. This is how I measured it: First, check the diameter of the wheel's centre cap, it was 52mm. Then put a piece of masking tape approximately across the centre and measure 27mm (half) from at least 3 sides to get a reasonable idea of the centre of the wheel cap. Mark that with a horizontal line as one measuring point. Then, directly above the wheel on the guard, put another piece of masking tape in approximately the centre. Use a string line to find out the point on the guard above the centre of the wheel cap and mark that. Then it is simple, just a tape measure to check the distance from centre of the wheel to the centre of the guard. Final results where  LF: 381mm RF: 379mm LR: 401mm RR: 400mm Pretty even considering they are 120,000klm old factory springs, lets call that 380 front and 400 rear.
    • So....knowing that I have a problem with power steering temps on track and another Wakefield day booked in next Friday, I've done the obvious thing They are very reasonably priced at $1650, considering they are a big monotube shock, double height adjustable (don't have to change pre-load to change ride height), one way adjustable damping and standard sized and customisable springs if you want something other than what comes with them. They come with 9kg/mm front and 4.5kg/mm front and I went with that as a starting point because I'll add adjustable sway bars too https://justjap.com/products/bc-racing-coilover-kit-ds-ds-infiniti-q50-v37-14-current#description Unfortunately they didn't come with rear strut tops so I've re-used the factory ones which was a bit of a pain. Also, the adjuster for the rear shock will be an absolute nightmare to get at, and while there are extensions in the kit I can't see any way you can actually attach or use them
    • I also had 2 bulbs blow at once, years ago in the stagea. made for a fun drive home. The issue was the voltage regulator had failed in the alternator and it was giving 15+ volts. Really, I was lucky all that was fried were the headlight bulbs. So, I'd suggest you check the voltage across your battery terminals with the car running and warmed up. Yes, you will need a multimeter to do so, sorry.
    • Good work to think to check that, and thanks for coming back to post up the outcome.
×
×
  • Create New...