Guys,

I see a lot of complaints regarding the sensors causing running rich problems and so forth.

I have mentioned this before but no one picked up on it, I'll try again.

Since the sensors usually give a resistance that changes based on temp or something of that nature, could you not just leave the sensor in place, but cut the wiring and substitute a variable resistor that could be manually adjusted to simulate the input and you would be able to provide the desired value to the ECM to resolve the issue?

Some of you younger geniuses that are "experts" at something take this idea and see what you can come up with?

This might help a lot of people resolve some issues that frustrate them with their Rovers.

Think about a possible cost effective solution to a common problem, or is that being a judgemental a$$?

 

Potentiometers can offer such a method; however I would assume this would do nothing more than trick the engine into 20/20 vision (like glasses or contacts). The benefit of the ECM correction from the sensor output is irreplaceable. Instead the sensors are letting us know that other than normal conditions exist and need to be addressed. Warn components ETC... I have recently been working on the TPS. I think I found a potentiometer that can be simply modified for around $3.

 

I am just saying if a sensor replacement cost is a fortune, and you think the sensor is the problem, my alternative could allow you to correct an issue cheaply by providing a manual adjustment that could basically "override" the output of a suspected defective sensor that you cannot afford to replace.

 

Ahh; so if you already know the value of your defective part, you can adjust it to a more normal signal level. Sounds like a possibility. But I would think that if the sensor is weak to begin with, increasing the resistance or voltage level may speed up the end result of complete failure. Electrical components like these are problematic due to the heat and constant on/off use. If the sensors could be kept cool, longevity would help. But I think the answer to your theory is a bit easier than trying to find a weak value and add a value to increased the efficiency. Look around at inexpensive sensors that basically perform the same task. These sensors can be used with slight modification to thier fittings. I like the way you think. I will try to determine if what you are suggesting works on one of my bad TPS POTS.

 

I was reading it as bypassing the sensor completely and plugging your own value back into the ecm.

 

It would help to diagnose things too, I don't know about anybody else but I feel much better dropping money when I know it will fix the issue. although a live feed from sensors via a obd scanner would do the same thing, but i have obd1 so I haven't seen anything with that capability.

 

Chris-Bob that is exactly what I said.

" But I would think that if the sensor is weak to begin with, increasing the resistance or voltage level may speed up the end result of complete failure"

Clarification: Leave the sensor in place to fill the hole, wire in a potentiometer, adjust to obtain desired results from the ECM.

It would be even better if someone totally familar with the ECM and the specific sensors joined in the discussion. I am trying to provide a basic approach that may work as a cost effective solution. Turn on those thinking sells guys!

Any negatives?

Since we have expensive outdated ECM technology and sensors that are not cheap or easy to replace.

Just an old Aviation Electrician that worked on aircraft before lots of you were even born throwing out some ideas for consideration.

 

What you are talking about are "dummy" o2's, they mimic a working o2 and trick your ecu into thinking everything is hunky dory.
They are common to be used in place of the rear o2's so that the cats can be removed and you will not get a check engine light.

 

What Danny is talking about (I presume) is what the aviation folk generally call a break-out box. It allows you to plug into whatever system you want to troubleshoot or otherwise manipulate, and simulate or stimulate the appropriate signal that the system produces, or that the system is looking for. Aircraft companies will basically build an entire simulated aircraft this way at the beginning of a program. So you could either make a box that the sensor harness plugs into, and simulates the sensor or you could do the same basic thing but plug it directly into the ECM. In this way, you could troubleshoot for bad sensors, bad ECM, etc. So if you expect that your O2 sensor is bad, for example, you could plug that sensor's harness plug into the box, and if your engine then runs better, you can comfortably spend the cash on the new sensor. What you would need are specs on what each parameter is, in terms of what the ECM needs to see. For example, the range of resistance from the temp sensor, and what those corresponding output temp values should be. The problem, I would think, would be getting ahold of those specs. Building it would be comparatively simple.

 

What sensors? Cam (NO), Crank (NO), KnocK ?, TPS (N0), Coolant temp (NO), Air temp for fuel (NO), MAF ?, Oil press ?

Not going to happen; Falsly providing the engine with incorrect values will result in the engine eventually tearing itself down, especially by inputting other than the values displaying key conditions. The sensors are designed to offer the input of various conditions, even while the sensor is weak. Conditions of wearing or warn out parts, like oil pump (pressure). I will stick to my original comment on using other inexpensive sensors in place and developing simple modifications to recieve the end result.