I stand down good sir, I stand down. You know your efi's well. I actually vaguely knew about lean burn but now I know in full.
Just wanted to make a point about carbed mpg since I hear it so often as a complaint.
Oh, they dont have to change the jets to get their 25 mpg. They can jet for the 25 mpg initially and use a 9.5 or 10.5 (I use 9.5 usually) power valve. That way, it always runs lean until you need it, then the carb richens the mixture real early. Thats a crazy pete tip. Then add a huge fat 1200 Joule spark from a hi-6 shooting into a side gapped plug to burn it all and you can get the best of both worlds.
But.... I do have to say, most people would know as much about playing with fuel maps on a programmable unit as they would changing parts in a carb. And tweecers arent cheap.
Most of all, this is my major complaint about efi:
My car did "weird ****" and I couldnt figure out why. Sometimes it ran, sometimes it didnt. I was looking at an almost 13 year old efi system with 8 injectors, fuel pump, fuel pump relay, pressure regulator, tps, maf, the barometric bulb, temp sensor, (I dont know if it actually uses the other sensors) plus some relays. The problem could have been anywhere. After spending almost $900 and 2 months, I still had a car that died unexpectedly. Now I'm certain that your particular efi is sparkling brand new gleaming wires and lovingly taped harnesses running wires to beautful brand new injectors and absolute brand new sensing equiptment
.....but old grungy 13-15 year old efi wiring and gummed old sensors with frayed connectors is something else. 25 lbs of wiring I ripped out: who knows where the problem was. I replaced all that above with a mechanical pump and a box that spews gas and a stand alone epxoy sealed ignition system. I have 2 variables: fuel and spark and the spark I can test by hooking a timing light to any plug wire. The fuel I can look down into the carb and see if gas is coming out. No guesswork! Thats the part I like. I can actually see whats going on
Now you say the efi can report failure codes.....but even if youre efi reports a code.....how do you know it's right? Codes cascade, sensors get old and tired. For me, the problem turned out to be that for some inexplicable reason the ground running to the maf and computer was showing a few volts (?!? Still never figured out why). What would the tweecer show on my 91? It would say "iiiieeeeee!!! plop!" then you would be standing there digging through 25 lbs of harnesses looking for that loose connection, probing stuff looking at resistences across wires for a week. My exhaust rotted out a year before that and some unmetered air got to the drivers side O2 sensor. The car would die whenever it got hot. So you had 5 minutes or so to get to where you are going then eee and you are pushing your car to the side of the road. I mean it was dead. Now my carb wouldnt give a damn. It would just keep pumping gas if the exhaust fell out altogether.
If you have a complex system, you have many many points of failure. I'm sure 2 dozen sensors would make a much smoother system than a dozen sensors......but what happens when that system ages.....thats right, twice as many points of failure.
The brute force levers and springs technology of a carb is something I can wrap my mind around. I can actually go up to a stuck carb(?) and hit it and jiggle springs and levers and do something direct not involving parts swapping. I can blow out passages, jiggle floats, examine my needle seat with naked eye and shoot carb cleaner at the whole assembly. On the other hand if my TFI module or O2 sensor decides not to work, I can sorta stand there drooling on myself till I go out and buy a replacement. You cant DO anything to these systems to fix them without replacing expensive things.
And that was my point to begin with: simplicity is cheap and reliable and human accessible and electronics are closed box and expensive and more failure prone.
