Part two of two. This section discusses and shows an actual example of how the PCM determines fault codes for the TPS. Part 1 is here: • TPS (Throttle Position...
I have watched many other channels and this one is the VERY BEST in explaining what the issues are and how to address them...This guy is the VERY BEST !!
I have "turned wrenches" or parts changed for years...with varying results in terms of diagnosis..this 9 year old video (set) is the first time I've felt like I actually UNDERSTAND when and why and how Fuel injection works. Thank you so so much, very refreshing and less daunting
Very detailed intelligent presentation. I feel like i am in an engineering automotive class watching this video. Thank you for sharing your valuable knowledge to clueless people like me.
I hung around from part one because being apart of the 2% made me feel like the wealthy corporate Elites. It payed off with more nuggets of knowledge. This positive response goes for both of your vids. Thank you
I think what really completes this video is that you intentionally set a fault code using the TPS. Introducing false data is something that ScannerDanner does too and it's what really separates a lecture from a real world application. Learning theory only is pointless until you gain practical experience. You share both theory and practical experience with the viewer. It's more than just education it's experience as well. I think that's the core value to what makes your videos a cut above the rest. I honestly just figured that out and will probably try to include something like that in my videos as well. Please continue to do all of your future D&U videos using this same methodology. It's superb.
Thanks Devon, I was not sure that people would see what I was trying to do there and why. Dude- wait til you see my next video. it will be right up your alley, and it will be epic.
Just when you think this guy can't get any better... he does. I learnt so much from these two videos. No-one else on RU-vid can explain things this way - it's a true gift. "When I do stupid stuff to my car, we all get smarter." Classic - this sums up the learning perfectly.
I am from Indonesia. A very valuable lesson for a very fast change from carburetor cars to EFI systems and to ECU systems that make conventional mechanical headaches. The way you really helped me to know the basic problems in tackling modern cars .. You are my teacher. Thank you
Used this 2 part series on TPS diagnosis on my '94 Suburban using a DVOM. Tests confirmed I had a bad TPS, as voltage would drop out to zero every time I would pass 4 volts. Installed new TPS, and stalling problem solved. Excellent videos, excellent channel. THANK YOU.
Thank you- We resolved this issue as a result of your excellent instruction! In our case Throttle position was "noisy" as compared to Pedal Sensor. Hence the fault code. Based on your info- we determined that the problem was simply a dirty Throttle Body. The valve was struggling to muscle past the 30% mark which threw an error code- due to the fact that it was loaded up with carbon and other gunk. Removed, cleaned and re-installed the Throttle body and the car runs like a champ- no fault codes Thank you for your commitment to instructing us- We love your binary frankness. It works for us analytical types !
Awesome - I actually had this EXACT situation myself earlier this week. Very erratic TPS signal on a drive-by-wire system caused by carbon obstruction. Cleaning the TB fixed the problem. Seemed at first for sure it would have been a whole TB replacement but ended up being (another) free repair!
Hi, just to let you know that I’m really enjoying your videos, you are very straight and to the point and I can see that you don’t suffer fools gladly. I think that your approach to teaching really makes people put their brains into gear and start learning about diagnostics in the correct way. This is a fantastic channel for people who are serious about vehicle diagnostics. Thank you for everything that I am about to learn, Chris, U.K. 👍
I love your teaching styles and appreciate everything you do on RU-vid. Thank you for taking the time to teach those of us who live in RU-vid Land how to diagnose any unit in our car that may potentially be faulty. No more swaptron for me!
This channel is unlike any other automotive channel I've been to. I've learned more from just a few videos than I would ever learn on my own. Thanks Matt.
Great explanation and demonstration! I had one of the first EFI 5.0 mustangs when they were first introduced. At around 150k (I got 330k outta that car), it developed a miss that drove me nuts. Well..., off to, I think auto barn at the time in the early 90's to buy a scanner, which at that time with OBD1 only emitted audible tones that you had to reference with the provided book. Well, it pointed to the TPS, and the bell rang for me when I realized it was a mechanically controlled POT and my engine was behaving like the staticky volume control on my home stereo! I swapped it out and that solved the intermittent miss. Your videos are really clicking and I'm getting a better understanding of the map sensor and how it works similarly with the principles of a CV carb. If I'm correct, the map supports the signal from the TPS and confirms fuel delivery and mixture based on manifold pressure. Thanks for the effort you invest into your videos!
You make me wish I had stayed in school when I was in high school. Frontier Public Schools (16 at the time) had a program that sent some of us to Stillwater, OK and the course I chose was automotive. Don't know if I would've ended up being a mechanic but I do know now that it would've definitely been worth it. Appreciate helping me understand more of what's going on under my hood and with my problem!!!
great information for any entry level tech or even experienced technician as we sometimes over think things and forget about the basics like our reference sources with MAP , IAt and MAF Cant thank you enough for taking me back to school. Much respect.
I'm not auto-mechanic but i have a lot problems with this type of issue with my car, and you guess, i not get any reasonable answer from anybody, so, i can certainly conclude you are give to me the best answer for problems with my car and thank you very much.
Same thing, but from an philosophical point of view. In any case, thank's. P.S. This cat is an Shrodinger cat, and i'm pretty shore You tend to an philosophical way of thinking. Because Quantum Mechanic have a not in common anything of classical mechanic. But hey, i'm just want to thank. Greeting
Matt, I just recently had an issue with my 2001 Chevrolet S-10 4.3L throwing a P0122/P1122 codes. The idle had been erratic once in a blue moon, but no codes were ever set. Late last week though, it finally set these codes I mentioned above. I checked the 5V/ground reference/and signal wires, and they were fine (used both a DMM, and scan tool software). I finally got around to replacing the TPS on it today (pain in the ass on my truck by the way), and have been driving it for a while, and the codes haven't returned. I bench tested the old TPS with my DMM, and indeed there were dropouts in the wiper arm of the pot as I moved it back and forth from its springloaded position. It was the OE one for my truck, and it lasted over 160k, so I really can't complain about that. Great videos as always man!! Hope you keep it up!!!! :)
Wonderful information! No wonder codes can be wrong as you have just proven! I have a 95 Astro van that has turned evil! And I suspected the TPS because of it's job. My van stutters, stalls or won't start at all but starting fluid is always the miracle cure! Of course, my spark plugs suffered greatly. Even my mechanic who is ASAE certified is stumped. He said fuel pressure was good and my injector pulse was good and the MAF good. Because of the confused readings of the ECM, he suspects it. You have helped me understand a lot about sensors and how their changes in variance affect the brain! Thank you so much! I have a good amount of knowledge about cars and you've answered another point as to why so many sensors report almost the same condition? Now that I know how one sensor validates another, I have many things to ask my mechanic! I did know about the voltage resistance but you've give me so much more! Love your humor about these issues. Sometimes you've just got to laugh at things about life!
I'm brand new to working on cars but I've been fixing electronics for over a decade. I'm happy to learn how many things the two have in common, actually (part of me is inclined to sarcastically comment to myself "it's as if a car is just a big MACHINE" lol). I found this series VERY informative to a person like me. I just bought a somewhat lemony Suzuki Verona from a title pawn place and have been doing everything I can to fix it up. I went to Advance earlier today and got a reading that I have a fault with the TPS and the O2 sensors (though it didn't tell me which O2 sensor), and was very happy to find out how to start probing my TPS in this regard. Thank you for creating this channel, and especially this series of videos, and I'm looking forward to everything else I will learn here!
You are a perfect personality, Matt! Feels like I'm back in school with a class I enjoy complete with jokes to check if viewers are listening. I feel a slight drop in power b/w 3500-4000 rpm in my 1990 Miata if I go slow enough and let the revs build up. Rising through those rpms, I feel a small jerk and the car pulls forward (once the power comes "back"). These videos gave me confidence in a subject I'm only starting out in. I'll check back if I can figure it out (after cleaning the throttle body first, of course)!
The automotive scientist! Love learning n enjoy ur videos. My dream would b for u to do videos w my 01 mustang get. I have many issues, but it was my uncles car n he passed away from cancer n it's all I have left oh him except for memories. Everyone try's to convince me to get rid of her but I won't. She still has a lot of life left in her. Great engine, great tranny n solid coolant system. Bearings r wearing out, lower steering bushings, throttle issues, pulls is creaking, driver side window dnt open, a/c needs freon. Watching ur videos helped my do brakes, change tie rods, I put in a new water pump n belt. I appreciate what ur doin brother. Keep teaching my guru. -Big C
@@SchrodingersBox my i20 1.2 petrol tps signal wire has .30 volt and other wire is 5 volt. However, my idle rpm is very2 low 600 rpm as against the normal 850 rpm. Will adjusting to .45 volt brings the rpm to 850??
This guy is GREAT!!! Not only funny at times, but has a real talent at getting his information across. Though I'm not very "mechanically inclined," I have started to watch Matt's videos because "HE EXPLAINS & SHOWS HOW THINGS FUNCTION!!!" Many people have said that I get to 'Anal' about things and ask to many questions of how things work. Well, I feel much more confident about trying something new if I have information before hand. "Like Matt's videos and explanations." I will continue to watch his videos and have shared his name and videos with many of my friends who try to understand functions of vehicles before they just go and replace a part. Thank You Matt! I still don't know a whole lot yet, but I know much more than I did from just a few months ago when I first started watching your videos and I always "Dig" knowing how things work and operate before starting a task, if possible. You're the Sh_t Man!!!
Very Helpful Matt. I am working on a 92 Pontiac Trans Sport and after a full night in the ER last night from Carbon Monoxide poisoning of 20%, I am back in service.. That will teach me to not vent the exhaust out the door lol... Anyways, I have a hesitation in the engine at idle like a surge, and initially ruled out the TPS as the culprit, but after watching your videos, I have learned that other possibilities may be in tact here. I will be running tests that you had mentioned... Very Helpful and thanks again!
+stan miller Yes I'd start with a fuel trim analysis and see if you can identify lean or rich at the particular strategic learned cell at the point of hesitation. That should give a solid direction.
I gotta quit reading all the comments conversations or I'll get stuck and have to understand all of it. So many questions.... I don't need to know, yet. keep it up Matt
i just watched an hour of your egr vids to finally get back to part 2 of what i was originally interested in in the first place. Keep these vids coming man!!! Youre awesome!!!!
Finally problem solved when I set up a test rig for the TB the butterfly opened put the TB on the engine connected plug and again no buttery comment when I pressed the accelerator pedal buzzes out all the wiring from TB to PCM and one side of the coil open circuit ran temp wire TB opened when pressing the pedal cleared codes all gone hopefully never to return Many thanks for your help your presentations are the best Thanks Tony
THANK YOU! I'M OLD GEAR HEAD WHO MISSED THE COMPUTER AGE IN SCHOOL, U OF RU-vid IS MY NEW ALMA MATER! THE COMPUTER INFO IS IN A GOOD MANUAL, BUT NOT THE THEORY OF OPERATION. I'M PROUD TO SAY I'VE SCREWED-UP A COUPLE OF GOOD CARS BY SHORTING OUT THE COMPUTER TRYING TO FIGURE OUT THE GODDAM TPS! AND I DO OWN AN O-SCOPE, GOT IT FOR TEN BUCKS AT A YARD SALE...
Thank you for bringing technology and your style technical analysis back to automotive repair. Obviously, mechanics need to be electronic technicians. As an old school shade tree mechanic and an electronic tech for for thirty seven years, it is refreshing to review automotive troubleshooting that would be scary to some.
Pumkin Head Thanks bro. I agree 100%- it is essential that people who want to repair modern cars break out of the mindset where a wrench and socket set are the first tools that come to mind!
great information, I watch all vids you have and take notes and I now have a lot of knowledge on how to fix my own vehicles and diagnosing problems instead of dumping money in it when it's not necessary. kept it up brother good work!
Thanks for your reply sir.My tps checked out good so I cleaned my throttle body and that seems to have fixed my problem.Who says you can't teach an old dog (67). Thank you!You saved me about $35.
I just can’t get enough,the rest is just the beginning of all to come. I know that you know that they know,you’re the best. Thank you much and keep Them coming. 👏🚘👀🥰💯🇺🇸 22:36
Thank YOU!! You have spent a lot of your precious time enlightening people like myself & I appreciate it sincerely!!! You should be or maybe are.... a teacher.
so true!!! many people think you need to be an electrical wizard to use an oscilloscope. i found using an oscilloscope is what made my an electrical wizard though.
Thanks this helped me by giving me another direction to look. I have a vein style air meter though. I've unplugged the TPS on my daily to prevent surging in the meantime.
Hi Matt, So glad I took the time to watch, thanks for keeping it simple and clear with examples. I may not fully understand the communication of men about their peters, but I'm glad you don't have two or I'd be tempted to trust someone else to likely approach this wrong. And once again I'd have to figure it out, fix it and what ever else they messed up anyway. I love to learn, tho don't really want to focus here now, I know I'm the better for it. I don't like techno like I used to as it is being used against us in all the worst ways. But need to stay on top to counter techno intel ya know. Thanks again mak
Great in depth drill down into this subject of TPS. took my 94 lexus LS400 to dealer. To no avail not fixed they seemed dumbfounded after just doing the factory adjustment settings of the TPS same issue code after $143.00 hr Lexus customer abuse program.
Hey Doctor! I call you Dr. Because I believe you are one for cars. And I am the 2% Here is my problem. 2003 make Suzuki Grand Vitara 3 dr. 2.0L 4cylinder engine with automatic transmission. Fuel consumption is like a 6.0 liter 8 cylinders- performance is like a air cooled 1967 VW Beetle. NO Check Engine lights (However I had the P0135 and P0141if I am not wrong for the heating circuit failure for both O2 sensors which have been replaced a couple of days ago and which are the actual reasons to put me in the 2% as you call it) I figured out that my car falls in OL Drive while I am driving normally. All measurements on the scanner somehow make sense to me (after what I have learned from your channel). For instance at idle STFT1 around 0,8...1,6% and LTFT1 is low accordingly. It's like heaven until I move the car. 1-When I push the throttle (not floor it, only push it a little hard) I see that it changes into OL Drive, thus (correct me if I am wrong) the fuel system says "balls to your sensors, I will do as I wish". That ends up in a gagging engine with No Go situation. I am suspicious about the TPS, because it shows 13,3% even at idle (is that normal?) and I can never reach 100% even when I floor the pedal. I believe or at least think that there should be a way to "teach" the ECU which ohm corresponds to zero and which ohm corresponds to 100% on the TPS potentiometer. (Because my TPS is fixed only by 2 screws and there isn't a way to "adjust its position to zero" prior to fixation. 2-I have also noticed that (apart from the example above) it goes into OL mode again when I leave the car into a "free roll" down a hill. No throttle but only gravity pulling the car down the hill. Please tell me, under which conditions does the engine go into OL? Certainly Cold engine is one and I think a throttle position over a certain limit should be another one since I believe the engine thinks "the guy wants to accelerate quickly" where/what else should I check?? Sorry for my poor English and thanks in advance for your support. Murat
greetings Matt, ol'fart here and i been watching your videos because i need to catch up on these new systems. I prefer noncomputered cars myself (i think i just invented a new reference you be the judge). Thank you I've learned quite a bit from you keep up the good work. P.S diggin the ride!
+mario zermeno Yeah everyone prefers non computerized because they are so much easier. But once you challenge to yourself to step up to modern technology, you will also actually be better with older cars too because they seem even more simple. It is a very good idea to catch up on these new systems as you are doing. We are 100% certain to continue in this path, and the ability to change points on a distributer will be completely obsolete and those who stay in the past will be passed.
Very good instructor, one suggestion, get some jumper wires, say from an old connector so you won't have such a hard time checking for power with your probes,remove wires from connector and install on pins,I'me not criticizing just a suggestion. Again thx for great tutorial!
Hello. Great videos. I have to admit, I was tempted to be a part of the 98 %. I thought you were quite cocky and arrogant. But, now being one of the 2 %. I get it. Thanks.
Thanks!! Yes it’s not until you “get it” that it all comes together. trust me- the cocky arrogant ones are the 98%’s. you have to be incredibly arrogant to spend hundreds or even thousands of dollars guessing at a problem and believing you are more skilled than someone like me.
This is great help. I have a rough idle condition and my acceleration is not smooth but I have no engine light or codes. I have a direction now, thank you.
+wyattoneable You have a definite direction indeed. You will find that the TPS is not your problem which will be helpful in your differential process of elimination.
Excellent. I actually had a TPS code and turned out to be a sticky MAP sensor. Wish i did watch this earlier it would save me alot of head scratching :P Thanks
LOL...19:27...20:53......humorous...quick-witted....charismatic....powerfully smart....articulate....this man is a 2019 Corvette Stingray incarnate...or a descendant of Master Yoda!
This explains why I had a TPS that went bad, the car kept giving a code for bad MAF sensor. I was perplexed because the MAF data looked perfect on the scan tool.
EXACTLY!! I call these “references codes”. The PCM can’t correct determine the particular sensor responsible so it references the wrong one. Happens all the time. Cam and Crank sensor codes also are very often referenced codes.
I have an oscilloscope I bought it to better understand electronics and to be honest I also wanted to learn all about using a scope. It was a good idea, my electronics knowledge improved along with being able to observe and verify it all. You can buy a reasonable one for about $400.. (Rigol, Siglent, for example)
I love your lessons, I don't have a Rice Burner but I do have a Sauerkraut Burner. It's a 2002 VW Beetle 1.9 TDI diesel. My problems started when I went to move it and it wouldn't come out of park but after pushing down real hard on the shifter it came out and went through every gear but wouldn't crank, nothing happened when I turned the key. Code was for Natural safty switch, I changed it, now it will start and drive but still indicates it's in every gear and it's in that Damn limp mode the new codes are...... P0228 Throttle/ Pedal sensor position sensor C- circuit high input. P0705 Transmission range sensor A-circuit low input I'm not a mechanic so I'm asking for any advice. Thanks Harold
I think you may have forgotten about the IAC valve opening up. This is why your RPM increased. It wasn't just more fuel. It was more air and fuel unless I missed something. BTW you're doing an awesome job my friend. I'm feeling threatened :)
ScannerDanner Premium Hahaha no I am threatened, you are probably right HOWEVER- it still makes the point that the PCM knew to credit the error to the TPS and not the IAC, MAP or anything else.
Agree bro but I have seen discrepancies. Like a glitching TPS cause a false MAF code on a Kia or Hyundai (can't remember). Or a dirty throttle body on an electronic throttle control system set a false MAF code when the problem was too high of a throttle angle. Poor software coding or engineering is what I would say the issues are there. So I would agree with you again Matt with this video but...sigh I work on 40 different car lines and there is no standard. :)
ScannerDanner Premium Really??? OK that changes everything. I will look into that. I haven't seen that video of yours. Why are you watching this video instead of my groundbreaking O2 sensor experiment???
I was bro, then I watched some more :) Nice job on the tomato sensor! Here is the link to the false MAP code video I did m.ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-4C075DS2Ud4.html
Yes these methods are essential and we do have to prioritize with any checking that is possible as we change all... and that's all of the parts.. that we can access.. it's good to have somehow a procedural precautionary list of priority things to change ..with anything but a new vehicle..... frugality and complacency can and must not apply..... Lives have been lost on the freeway as people stall out unpredictably.. persistent part changing... even transcends imechanics precision and possibly presumptuous or complacent accuracy
Well to each his own but I am not changing parts that are proven to be functional. If a tuneup makes you feel better- maybe it's worth it. But it won't make the car feel better if there's nothing wrong. I see no point wasting money for no logical reason or through lack of compehension on how to properly evaluate.
please, please, PLEASE continue to make videos!!! super informative!! equivalent to GOLD even!! and i completely agree with some of the commenters on here: please invest in a scope!
Hi Matt What great videos these are, thanks for posting. I've always had to fix my own car in the past but now with these computer ones I need lessons like yours. I'm 61 now but as they say, never stop learning. I went to college for three years learning Electonics so I can understand the comparator circuit principle. Where do you come from as when you pronounce potentionmeter you say it different than us in England. Like po-ten-she-ometer, interesting. I've got a Nissan Almera 1500cc year1 999 I've had it 10 months now and it's always had hesitation 62mph in 5th gear and in other gears also does the same. I opened the electric window once and the car didn't start for three days, it did crank over though, then ok. I went to come home the other evening and it wouldn't start, like it didn't have any fuel, it started for a little bit and then died. I put some petrol in and after a few cranks it started. It got me home but I then went to go out later and just cranking. Next day it started. But I had to walk home as the battery went flat trying to start it. I charged it and then it started. So you see I really need to learn this stuff. PS. I've got an anologue needle meter which is another option than the digital meter, what do you think. Thanks again and any info would be great. PS I found the problem, it was an intermittant fault on the fuel relay. Singem.
Lol yeah I kinda didn’t think that was my problem but he’s supposed to be a mechanic so I figured I’d listen. I still can’t seem to figure out my problem tho. I always have to put fuel in the throttle to start it. Fuel pressure is at 40psi until I start it with gas in the throttle. The fuel pump and filter were replaced a year ago. So I’m trying to see if it’s something more simple before dropping my tank again. It’s a 1997 Chevy blazer 2dr 4x4. 4.3 V6 vortec. And I lose power when accelerating and stalls sometimes at stops. I’ve cleaned the throttle body the egr, replaced pressure sensor, found I didn’t have a thermostat that is now in, I’ve checked the vacuum hoses. Cleaned the pcv valve, the iac, Put in catalytic cleaner and fuel injector cleaner. My dad was convinced it was the ignition control module which he replaced but I didn’t think that was it and it wasn’t. I think my next step is fuel pressure regulator and distributor cap. My oil gauges is really high when I first start it but after driving awhile it goes down really low. And it’s impossible for me to go uphill. And it stalls more often when the engine warms up. Although I’ve watched a lot of your videos and have learned a lot I can’t seem to pinpoint it cuz the symptoms I’m having seems like it could be anything. Even something as simple as a bad ground.
Matt you definitely need a second penus. The dmm will and does work but a scope is wow - you will think you've been living under a rock. I bought the Pico 2 years ago because the dmm was not fast enough. I had a chev g van with a transmission late second gear shift with no cel. I did the sweep check with the dmm and it was ok , at this point I took out the Pico and surprisingly with a rapid sweep of the throttle indeed I could see the dropout. Is the scope required no. Drive by wire testing for a tps is quite different . I have found out the hard way you need as much technology as possible to find a fault asap. I was amassed at first with the Pico how my dmm and autoenginuty scan data were either too slow or took an average reading. Fantastic series looking forward to more. Thanks.
You know, one of the reasons I brought up the oscilloscope was to probe on how many subs have one. Turns out it's quite a few. I will consider it more now than I did before!
I also got a pico 4 channel like scanner danner . cheap scopes can not zoom in on problems like injector pintel humps closing differnt times ..... but i do think a scope is a must have pico have a new one come out now also in case this is important to someone. a cheap scope is affordable for anyone who fixes cars maybe not a pico but there is plenty other pc based scopes and cheap handheld like the valeman 150
Intrade motor - could not agree more, seems a lot of us following SD do have a Pico scope. Seine waves , square waves ,pressure transducers ect. I found the learning curve with Pico quite easy compared to a manual scope with no pre set test features. SD has convinced me the benefits to the snap on solus pro - puts my autoenginuty to shame , maybe Santa will come thru LOL. 😄
Not if you want the Best you need a pico 4000 or buy the new one come out, or the ats GMTO these are the top 2 for automotive GM uses the picoscope as must have for 2014 vehicle diagnostic and branded a pico with GM logo as there oem test equipment . With pico you have the advantage that danner uses it and lots of other professionals who supply youtube information like autoinform or tstseminars. The pico software is free to use in demo mode for anyone to mess with.only waveform libary is only functional once you connect the actuarl unit. the software stays the same in demo and with scope attached on pico. www.picoauto.com/software-picoscope-automotive.html
I have a fluke 87 v for meter. multiple flukes actually... Innova 3130 for a scanner> It works.... but I don't have a scope. Would be cool to some videos of that though. Great videos Matt
Very interesting explanations...really learn a lot. I'm in the 2% who loves learning about the technical features. This episode (1&2)) helps me understand the interrelations between 3 critic components regarding air and fuel. Thanks for taking the time. Note: To minimize or maybe prevent shorting the PCM would it not be safer to separately back-stab the the three wires feeding the TPS rather than touching the terminal ends? (Of course one must still be aware of supplying positive or negative hook-ups.) Again your presentations are powerful.
Yes I agree the DVOM is not only useful for people who don't own a scantool, but I found that it also adds to the learning of the function as well since people "see" it better with a DVOM.
Very interesting. I suppose, that to your second point regarding 'why all these sensors', i.e. that the responsiveness of the engine is improved, that the inclusion of an APPS in a drive by wire system [like on my 2006 Camry] would enhance that responsiveness even more. The PCM wouldn't have to wait as long to know the throttle plate was being moved by a physical linkage...it would know immediately from the APPS. Thinking further, it would actually be the computer moving the throttle so it would know, almost ahead of time really, what was going to happen and could set the fuel flow accordingly and then get feedback from the other sensors and correct as needed.
If you don't want to invest in an expensive oscilloscope, you can buy a DS0150 oscilloscope for under $40. It doesn't have a lot of bandwidth, but it can show you all the signals on a motor vehicle and best of all, it runs on a 9V battery; so it's portable.
Wow! Great stuff! And your eccentricity! lol Just great. I have been working on a 2.2 ecotec in a 95 cavalier and the thing is dying during high torque loads, seems like during automatic gear shift changes. Idling low too. I can pop it into neutral and start it if I give it a lot of gas, usually, even while coasting. I will drive it to o'rileys and use their computer to see if it throwing codes, but I might use my ohmmeter to have a look at a few of the components, now that I have an idea. Thanks!
