engine control Unit ECU

[forrestgump]

Hello I have been having some small problems with my old car lately and was wondering if anyone has seen a kit or plans etc... to make an ECU to monitor and/or control sensors in a car. I would like to be able to monitor not just simple things like voltage and rpm but oxygen sensor, crankshaft sensor, fuel injector duration etc. I have seen some commercial ones out there but cost big $$$$ I doesn't seam that it would be that hard to tap into the wiring to monitor things like oxygen sensor but I could be wrong. It would be nice to force variables in the car to see what results you can achieve? Better gas mileage etc? If anyone has any info it is apprechiated!<p>Thanks
Mark

[Chris Smith]

For the most part, you don't want to "force anything". There are chips that alter settings continually while the motor is in motion, but you cant force manual settings because most people don't have a clue as to how a motor really works, nor could they keep up with the dynamics of a moving car and its changing factors. Ox sensors for example are only a "pooper scooper" when the motor isn't running quite right, but by law its input can not alter the motors running conditions by more than a few percent over all, based solely on the out put gas in the exhaust manifold. Connecting and disconnecting the sensor alters nothing noticeable to the user, changing only a small reading on the test equipment by a factor of .02 in the HC reading. More pollution will be your only gain, most likely, unless you truly understand the dynamics of how to produce power and why.

[Externet]

Hi Mark.<p>It is a big can of worms, spiders and bugs.<p>Not to answer your question but for you to sense how this ball game is played, visit:<p>http://www.starrperformance.com.au/efilivev5/index.htm<p>Enjoy,<p>Miguel

[keymaker]

No I think the oxygen sensor sends a signal to the computer to richen or lean out the mixture according to some type of level in the actual exhaust.

[Chris Smith]

Having my smog licence in the 80's, It only affects a extreamly small percent of mixture control working only if the rest of the car is in complete working order. If a miss is present in the motor, this amount of excess HC will over ride the sensor to the tune of about 100, to 1000 times its limited control driving the ox sensor to saturation and thus out of control or shut down.

[forrestgump]

Hmmm it seams there is allot more to this then I first thought? I was willing to sacrifice my 1989 Dodge Shadow to some experiments though. It works well but is very hard on gas. From my understanding the oxygen sensor sends pulses back to the computer sorta like an off on but in code. I was thinking of building some circuit to read the true values and alter them for the computer. I think I will start there just to play. Any insight is still welecome!<p>Thanks for all the reply's
Mark

[Chris Smith]

The oxygen sensor does not send codes, it sends a voltage generated signal that converts the unburned gas in the manifold directly into electricity similar to a photo cell which converts light into electrical flow. The computer deciphers the amount of current/voltage and in turn interprets this signal into logic. As I recall this voltage was some where in the amount of less than 5 volts, [or point five] down to around 2.4 volts [or .24] ? The air flow sensor if present, and the temperature sensor are the only direct input that affects mixture percentage ratios across the board. However play with these and too lean will burn valves and pistons.<p>[ February 19, 2002: Message edited by: Chris Smith ]</p>

[MOVEME]

Okayjell: Its' my understanding that if you have electronic ignition, then all nerves end there, and potentially can be, voodood with long pins(eh,eh). There are, more and more performance type "boxes" availible from race outlets, but of course that will only get you to the pumps FASTER. If you want to learn more about whats going on inside yer "mill" I would say start with plug inspections, compression checks,general tuning and, I learnd alot by installing a manifold vacume gauge and noteing readings under various loads. If/when I do watch it, I can pick up a few miles on the gallon easy.<p>Moveme/ to Kuait