lol, ey man, i'm not tryin to be a dick.
i wrote that because that's what i had to say to myself when i was under the gun to save my 240.
i was literally cramming 240 info into my head for days on end.
sensor testing, vacuum diagrams, electrical circuit voltage needs, torque specs, component operations, ecu code checks
i'd wake up lying on the spread out books and pages only to read vacuum diagrams while eating cereal cuz i was sure i'd forgotten something. ;]
you wanna talk "pain in the ass", teach yourself how to read a wiring diagram. lol, i'm still no good with that.. as for knowing knowing what's all in one circuit... the fun part is modding a stereo system... when you do it professionally off the original battery.. you have to add up every resistor (pretty much anything that uses electricity, including the length of the wire) so you know that every resistor along that circuit has the amount of juice it needs by the time it reaches the end of the line.
there's more than one thing that robs a car of it's power.
there's a guy on here with a signature qoute...
"Your car's the sum of it's parts."
i'm bored, i'll make this a long, shootin tha sh!t, sorta reply, and i'll probably miss some things you asked.
k... power band lag... you feel power and then it lags at a certain point..
1ST QUESTION: is it completely congruent with your pedal position, or with the engine rpm? does it happen right before a shift when a certain gear might be getting too much torque for an old tranny? or just when you're applying throttle (air) to the car.
if it's the pedal position...
it could be TPS (that lovely picture, the guy was nice enough to find for ya),
because of this...
like it shows you in the diagram, the needle (connected to your throttle butterfly valve) sends an increasing amount of voltages to the ecu as you open the throttle... as the throttle is applied, the voltage increases, letting the ecu know exactly where the throttle is(ONE OF YOUR REASONS WHY FUEL INJECTION ENGINES ARE SO FINELY TUNED..this works along with the Crank Position on the distributor ~what fires the plugs~ so that the ecu knows when to spray the injectors... on old carb engines this is done by the fuel pump that has a rod running off the camshaft [MAKING EVERYTHING WORK IN UNISUN... AIR, FUEL, SPARK]). if the sensor is giving erroneous readings, it'll throw the computer off, things won't work right and it won't get enough fuel for the air coming in??? *thinking*
if your voltage output from the TPS drops at the same time the CPS is giving a reading of crank revs, then it's almost like the engine rpm is still the same but there isn't enough air, in turn it not needing the fuel, so it lessens the amount of...
damnit i'm doing it again... i'm in a spiral of thought.
the CPS is more for the spark than it is the fuel, but it still coexists with it.... the rotor cap is mechanically linked to the timing... allowing the spinning rotor to spark at the time it passes the cap's metal notches (this is how you play with spark timing a lil... rotate the cap... you're advancing or retarding the spark) but there's also a light diode in there that shines through slits.. when the light hits the other side... that's the degrees of timing... allowing the computer to also know the crank position for the fuel timing... but i think it also helps the computer adjust the spark timing.. no... i don't know... i need to read more! lol.
when i think about it... a fuel injector is operated by a small solenoid... it recieves a voltage output from the ecu... it opens the injector, and due to the pressure in the system from the fuel pump... it sprays fuel for as long as the solenoid is open... there's no in between, it opens, it closes. (this is how you test injector solenoids... apply current... it clicks... but you also have to test the spray... "if it's clogged") but the timing of how long it's open is all due to how long the ecu passes current to them. and of course, all off the CPS (crank position sensor) and TPS (i think.. i'm not sure which one tells the ecu to spray the injectors!!!!)
if the TPS is sending a small voltage when it should be sending a higher voltage... the ecu thinks you're letting off the gas pedal. (the Air Pedal)
basically... your computer thinks you're letting off the pedal, but you've obviously got the throttle open... the engine is getting air, but it's not giving fuel...
but here's where i get confused...
the TPS says "Hey, i'm trying to go faster. There's plenty of air."
the CPS says "Hey, this is where the pistons are. This is when you need to give me fuel and spark."
if your tps is going out.. it's like your telling the ECU, "Your not getting enough air for how fast you're going. Slow down, and Stop giving so much fuel so you're not running rich or flooding the engine."
but your engine IS getting the air. so it's like you're really running lean.. your engine stops asking for fuel and wants more air. in turn, making the engine run more lean for a second, then when you press the pedal harder, it gets to a point to where the TPS inside the sensor is fine... and then your ECU realizes you're gettin the air all of a sudden and it start giving the correct amount of fuel again.
damn... i need a drink.
that's right, right? someone, anyone?
damnit, WHO KNOWS IF IT'S THE tps OR THE cps THAT TELLS THE ecu TO OPEN THE INJECTOR SOLENOIDS?
i'm confused now.
when you droptest that sensor your just trying to get the reading of the increasing voltage; you don't get the readings your FSM tells you (or close readings) then it's not working properly. thing is though, it's pretty obvious on your car when the full throttle position isn't working... when you push the pedal to the floor you don't get the feeling of the car downshifting if it's at the right rpm, or steadily increasing in speed.
if you've got an auto tranny it can be a point to where the rpms aren't high enough for shifting, but low enough to not have that last bit of torque just before shifting. but that's more of just regular engineered gearing... it would act the same way the first day off the dealership lot.
or... like that one guy said, a slightly mushroom gear could keep it from catching quite right...
but that mostly happens when ppl jam the gas pedal down during midshift... reving up the engine before it's in gear is bad on any kind of car...
that's how you blow a tranny.
1994 XE)
