Testing for Injector Pulse and Spark on a 5.0L Mustang

[@AndrewBrowner]

this is how repair videos should be.. actual troubleshooting.. not just firing the parts cannon blindly based off an obd code should expand on this make it into a series on more common vehicles, issues, tests ect

[@dragradialperformance3540]

If we can ever find the time, we would like to make some quality, edited videos. Subscribe, and get notifications I guess. Eventually, we will!

[@Scruffy72]

Fantastic breakdown here. Car started fine the other day. But today it turns over but no start. I checked the distributor and coil pack which both were working good. I havent checked the injector yet but that will be the next thing. I also have fuel going to the shreider valve. One thing i noticed was when the key is turned to the run position, the fuel pump stays on. Im thinking the ECU has an issue not grounding properly.

[@dragradialperformance3540]

When you hear the pump run constantly, it likely means one of two things. Either the fuel pump relay control wire is accidentally touching ground, or the PCM has bad capacitors (and possibly other related board damage). It's almost always the latter. Remove the PCM and pop the cover off. Carefully inspect the 3 teal blue capacitors with a bright light and a magnifying glass. If you see any corrosion on the legs or feet of those capacitors, or they're broken, swollen, or popped, then that's the problem. To be honest, they are way past their life expectancy, so if they are the original teal blue capacitors still, they need to be replaced. By someone who seriously knows what they're doing. I have a guy if you need one, and we carry the capacitor kits for like $15 plus shipping.

[@Scruffy72]

I just now saw your response. The issue is 100% the PCM, I checked the fuel pump relay chichi was working properly. I also checked the injector which was getting constant power to both wires, when the key was on. I took the PCM apart and the board looked solid with no corrosion on the board. All 3 capacitors were broken or leaking however, I replaced them all with new ones. Unfortunately I still have the same issue on install. It's likely that I damaged the lines in the board during the replacement. Which is garenteed at this point. Since I threw in a 92 Bronco 5.0 PCM for a second. I noticed that the fuel pump would prime properly. I appreciate you taking the time to respond.

[@dragradialperformance3540]

@@Scruffy72 the PCM is saveable, but now it needs to be fixed by an expert. Trying to do it yourself likely made the damage worse.

[@PANTYEATR1]

i mostly use paper clips and a multimeter with alligator clips on the probes. T-pins are allot nicer imo.

[@vig37]

My guy, you're so clear, concise, enunciate so well and know how to distribute knowledge so effortlessly and so that an everyman can follow your tutorial. If you aren't teaching, you ought to. You would make a great instructor in a classroom as well as online...sorta like Scanner Danner. I can't understand why your channel isn't off the charts popular. Edit: I made sure to like and subscribe. Thank you for doing what you do.

[@dragradialperformance3540]

Thanks for the kind words. Paul Danner is a friend, and an excellent source to learn stuff like this from. I try to make this stuff useful mostly to Mustang owners, although much of the info is universal.

[@ramongalaz6263]

Good morning this morning i took and the distributor and left everything connected and grounded it to engine and turned it over by hand and started getting coil spark and injector pulse.I added another engine ground and cleaned around distributor and placed it back in.Once installed turned key over and nothing at all

[@dragradialperformance3540]

If turning the distributor by hand makes sparks and injector pulses and fuel pump run, then the distributor is working fine. Make sure the gear is attached to the shaft at the bottom, and not free spinning. And install it and make sure that when you crank it, the rotor spins.

[@ramongalaz6263]

I found a partial problem.I got the engine running spark and injector pulse. Found that the starter solenoid s terminal wire will make the engine run when i jump it direct from the battery but when i hook the s terminal wire back it will only crank no spark or injector pulse.But there is a signal with 12 volt coming from ignition switch.Any ideas please and thank you.

[@ramongalaz6263]

I have a 5.0 I have a random EFI distributor here, so I hooked it up to the harness plug, grounded it to engine, and spun it by hand. Bam!....lots of clicking(injectors) and lots of flashes(noid).But when i place in back in engine no pulse on injector or pulse on coil

[@dragradialperformance3540]

Remove the cap and see if the rotor turns when you crank the engine. Maybe it's a broke timing chain, cam, or cam gear if it doesn't spin. The TFI module only provides spark, but the PIP Sensor inside the distributor will affect spark, Injector pulse, and fuel pump relay operation. That's all the clicking and activity you're hearing when you spin the spare distributor. You're on the right track. Now just figure out if it's PIP You're missing, or spark only, or if the distributor isn't actually spinning.

[@Mecanicaencasa]

Great video

[@ramongalaz6263]

Yes gear at the bottom in good shape

[@dragradialperformance3540]

Make sure the roll pin isn't broken, and gear doesn't turn on shaft.

[@nikolincurri840]

You have puted the backprobe on the Ground controlled signal and after that 1 lead of the test light on the auto body ground and the other lead of the light You puted on backprobe which it should be grounded .....how does the light turn on ? When both leads are grounded ? Explane to me please.....

[@dragradialperformance3540]

I explained this in the video. The power comes from the PCM relay to all 8 injectors. When the injector is OFF, the power winds thru the injector windings, and comes out the other side, to the negative side of the injector, and continues to flow all the way back to the PCM itself. So when the injector is off, there is power on BOTH sides of the injector. This happens because the injector windings are simply one long, coated wire wrapped around an iron core. When the injector is off, there is no current flow, and therefore there is no voltage drop across the resistance of the injector. When the injector is turned on (by the PCM grounding the injector), then there is current flow, and therefore there is a voltage drop across the resistance of the injector. With the injector off, there is 12v everywhere. With the injector on, there is power on one side of the injector, and ground on the other side. Since there is 12v on both wires when the injector is off, and since the test light is an LED light that requires very little current flow to light the LED, the LED will light because it has power coming from the injector control wire, and ground coming from the strut tower.

[@vapistf5828]

Im not getting a priming signal nor an injector signal when I turn my key. ECU and fuel relay have been replaced any help?

[@dragradialperformance3540]

The fuel pump should run for 1 second, every time you turn the key on. If it does not, your PCM is not functioning. That could be either a power/ground issue to the PCM, or it could be the PCM itself. These Fox computers are well known for having capacitor issues. They're about 15 years past the life expectancy of those capacitors at this point. The next step would be to check for powers and grounds at the PCM. Pins 37 and 57 for key on power, pin 1 for constant power, and pins 40 and 60 for ground. I would also pop the cover off the PCM and inspect all 3 teal blue capacitors for any sign of corrosion underneath them.

[@leobuck2060]

Thanks for this video... Took me a bit of searching to find something showing how to check for "injector pulse" (didn't know what it was actually called), as opposed to all the videos my search sent me to on how to check the injectors themselves... Which I did. QUESTION: What do you do when you get no injector pulse or no signal whatsoever to just one injector plug while all others are running fine. I've got an old Toyota 22re with a #4 cyl. Only coming up after 10 or 15 minutes and then cutting in and out intermittently. I've confirmed the injectors are good and even swapped #1 & #4 and #4 cyl. still down. I'm about to go out and run this test on a healthy plug, then #4 and see if it's the signal. I can't really think of what else it could be unless it's in the valve train... I've already checked for spark.

[@Pontisteve]

If the injector itself is fine, there are two reasons I can think of that would cause the PCM to not fire one injector. First of all, on modern cars if you get a misfire code (P030x), the PCM might intentionally shut down an injector to keep unburned fuel from being injected, which can cause a cat failure. Why inject fuel into a cylinder that the PCM knows can't fire the spark? The way to identify this is to test for injector pulse right away after starting the car, and continue testing for a minute. I can't speak for Toyota, but Ford will fire an injector no matter what for the first 20 seconds or so. After that, it won't fire an injector that has a coil or misfire code. So in this situation, you would have injector pulse at first, and later it would go away and stay away until you restart the car, at which time it would be back again for those first 20 seconds. Toyota might have similar technology. The second reason might be that the male PCM terminal for that one injector control wire might be not making connection with the female terminal for the PCM harness connector. It could be a pin fretting issue (weird vibration that wears the male terminal), or a bent pin (human error plugging the PCM in), or a broken terminal retaining clip. I've seen this before. I have a video of a Mustang doing this. It was losing injector pulse to one cylinder, and the problem turned out to be the plastic finger on the PCM connector was old and brittle, and broke off. So it looked like that wire and terminal was fully seated into the PCM connector, but when you push the connector onto the PCM, it was pushing the female terminal out of the connector, instead of inserting the male terminal into the female connector. Most other injector testing methods are crap. But you can ohm test all your injectors (unplugged injector, car off). Each injector should be between about 11 and 16 ohms, and should be within 0.1 to 0.2 ohms of each other. Testing all of them will reveal the pattern. You can also get into a situation where the injector is electrically fine, but mechanically stuck shut. This can happen when a car sits for a long time. Put a flathead screwdriver against each injector, and up to your ear. Listen to them all run. Even the dead one will sound like it's clicking, but it won't click as loud as the other ones. You might also feel the injector click. But a stuck shut injector will have the problem and the misfire code move as you move the injector to a different cylinder.

[@leobuck2060]

@@Pontisteve thanks. This is an 89 Toyota pickup. OBD1, distributor ignition, and I wasn't even getting a CEL. All the injectors have checked out with ohm meter, all dead 14.1, just below range max., All checked for open and close, and all checked for nice even spray. Your advice on tracing the wire is what I'm thinking. I'm assuming there will be a dedicated pin, or pair of pins, for each injector. I'm not sure if it's set up with a separate module for the injectors or if everything comes from the ECU, but whatever it is I'm pretty certain it hasn't been unplugged in at least 18 years. It's a good possibility one of the wires has gotten a nick and short it out somewhere in that 33-year-old harness. This should be fun...

[@MichaelJohnson-cm4wp]

With 12 volts going to each injector, splicing into that power source and installing a toggle switch located in a place under the dash that you can reach..hidden from sight..would be an excellent theft deterrent..Toggle the switch to cut current to the injectors and the engine never starts..switch it to power and off you go..

[@Pontisteve]

If you want to do that, it would be better to interrupt the power or ground going to the control side of the PCM relay. That would kill power to all of the EFI, and would be much harder to work around.

[@MichaelJohnson-cm4wp]

@@Pontisteve That is a good idea..I have a 94 Ford E350 Ryder moving van. 460 engine with E4OD trans..Bought in 2001 for my construction business..I am going through the whole thing..Rebuild engine, trans and have pulled all the engine control wire harnesses.. Your idea would shut all of the EFI down with one toggle switch..No fuel pump..no nothing..ECM needs new caps..When the van is done, I am leaving California to who knows where and I need this van to be totally reliable and also not to be stolen while it is parked in a hotel parking lot for the night..

[@Pontisteve]

@@MichaelJohnson-cm4wp Good call on replacing the caps in the PCM. Be sure to remove the conformal coating around the base of the capacitors first, replace the caps, and thoroughly clean the area around their base with high purity rubbing alcohol and a toothbrush to kill any remaining acid and keep it from continuing to eat. The acid eats not only the capacitor legs, but also the printed circuits nearby.F And a big congratulations on leaving California!

[@MichaelJohnson-cm4wp]

@@Pontisteve I am so old school..grew up in the 70s where a engine just needed a correct gaped points..new condenser..fresh plugs and adjustment of the carb using a vacuum gauge !! LONG GONE!!..Now one little green crusty connection..one mouse wire chewing and your engine is dead..A dead band TPS and your engine dies at the line..Transmissions shifting weird because a TPS problem..Over rich condition because of a cold water temp sensor..On and on.. I want to buy a scope..I was thinking of the Hantek 1008c to start and learn then move up..Just to check injector performance and stuff..I really enjoy the learning curve of all of this.. Kansas..that is what I am thinking of going..

[@Pontisteve]

@@MichaelJohnson-cm4wp I have a Picoscope 4 channel master kit, and it is amazing. But price wise, it's the deep end of the pool. I would still go for it, but if you want to start out lighter, look at the Autel scope or a used snap-on scantool that has a built-in 4 channel scope.

[@johncaywood1302]

What was the was the problem with the fuel injectors?

[@dragradialperformance3540]

This video was designed to show you how to test injector pulse. It wasn't a case study on diagnosing this particular car. There wasn't anything wrong with this car, I was just using it to make videos. I probably disabled the injector pulse for this video by removing the PCM. (You would still have spark, even with the PCM not installed, since the TFI module will fire the coils off of either the PIP or SPOUT signals).

[@392_mario]

Do you have a video on foxbody ground wires and locations and how can you add grounds if you should have to

[@dragradialperformance3540]

No, not yet. But there are only 2 PCM grounds to be concerned with, and one battery ground. There is a PCM case ground (and ignition ground) located in the passenger fenderwell, right behind and below the computer. Then there's the main PCM ground, which is a single black wire connector that attaches to the fender by the rear of the battery, near the starter solenoid. That wire attaches the PCM to the inner fender. Then there's the small negative battery cable/wire. It goes from the battery to the fender, and is quite important. Just check those three places. No real need to upgrade ground wires if they are in good condition. Each should have less than 50 Millivolts on them when the key is on or the engine is running.

[@PANTYEATR1]

if you want a nice project, build a dedicated ground. connect a 2ga wire directly to the battery NEG and ground that to the body, a few seat belt bolts and in the trunk area. clean the metal till shiny, add dielectric grease and a star washer and you'll have an unbeatable grounded vehicle.

[@canaryinacoalmine8746]

How was this going to pulse when you have disconnected the computer?

[@dragradialperformance3540]

It wasn't. I was showing that with the engine disabled what spark and injector pulse looked like, and stated that if it weren't disabled the test light would be blinking. The video shows how to test for injector pulse. Regardless of whether the car has it or doesn't have it in this video, you still see how to check it.

[@canaryinacoalmine8746]

Ok, I have injector pulse but no fuel to the plugs 🤔

[@dragradialperformance3540]

@@canaryinacoalmine8746 The injector needs two things to fire: Key-on 12v power on the red wire, and a ground pulse from the PCM on the other wire. A test light lets you check each wire independently. A NOID light lets you check for both of these things simultaneously, and hands free. If the power and ground pulse are getting to the injector plug, then that connector must be able to transmit them into the injector terminals. In other words, good contact, correct fitting pins, and no corrosion. If the injector actually gets the power and ground pulse, then it should electrically turn on the injector's electromagnet, current should flow, and the injector pintle should open. The injector will make a clicking sound and feel. If the pintle is not physically stuck shut (usually due to injectors sitting for a long time with ethanol laden fuel in them), then fuel should flow thru the injector while it's on. This not only means the fuel pump must be working and creating 39 PSI at the rail, but it also means the injector bucket filter (pressed into the top of the injector) must also be clean enough to let fuel into the top of the injector. That bucket filter is the last chance for fuel to be filtered before it gets into the injector's internals. When injectors stick shut, it's usually not all 8 of them. It could be several though. Tapping on the injector may unstick them. You can try cranking the engine over while pinching the injector with your fingers, to see if you feel it clicking on and off. That clicking most likely tells you the electronics are all good, but cannot tell you if fuel is capable of actually flowing thru that injector (if it's stuck closed mechanically).

[@canaryinacoalmine8746]

@@dragradialperformance3540 Thanks champ. Explained in detail. Great work you have gone the extra mile. Much appreciated 👍🙂

[@Nemesis74racer]

Late to the game but if it was due to fuel pressure why or rather how could that cause no spark? Meaning, if it was fuel related wouldn't the test light flicker to show signs that it's not ignition coil/connector related but something else?

[@Pontisteve]

It was not due to fuel pressure, it was due to lack of injector pulse. The coil test light was flickering, indicating you have PIP and coil control.

[@Nemesis74racer]

@@Pontisteve Sorry. What I meant was you mentioned if not coil/connector related then the fuel pressure could cause no spark. How could that be if it was fuel pressure related. In other words, let's says the coil/connectors/etc. all tested good then why would you think fuel pressure could be the main culprit? I'm just curious.

[@Pontisteve]

@@Nemesis74racer I'm not sure I follow. A fuel pressure issue would not cause a no spark issue. If I said that in the video, let me know what timestamp that's at. Now if coil control and injector control are present and the car still doesn't run, then certainly fuel pressure would be the next thing to check. Really, fuel pressure is usually one of the first things I check on a no-start, just because it's easy to test with a gauge and know for sure. Testing coil control is also super easy. Injector control is probably the hardest of those 3 things to check, so it would likely be the last of those 3 that I looked at.

[@laneburgess1643]

If you don’t have injector pulse and wiring is good. Does the computer require an input before it will pulse the injectors or will it pulse the injectors with out any inputs during starting?

[@dragradialperformance3540]

Both the PCM and the ignition module require some sort of signal or pulse to fire the injectors and the coil. The PIP sensor provides that pulse. The reluctor ring on the top of the distributor shaft has 8 teeth, and when each tooth goes thru the PIP sensor window, the PIP sensor produces a pulse. The pulse goes from the PIP sensor to the ignition module, and on to the computer. The computer uses it to fire the injectors, and also modifies the timing of that pulse and sends it back to the module (as a SPOUT signal) to fire the coil. If the module doesn't detect a SPOUT signal, it will fire the coil based on the PIP signal instead. So yes, the PCM requires an input to fire the coil. Next time your distributor is loose and you don't care about your timing setting, try rotating the distributor all the way left and right that you can. You'll hear an injector click, the fuel pump relay click on, and a spark occur.

[@laneburgess1643]

Thank you for answering my question.

[@driversinc]

@@dragradialperformance3540 Is there a a way to test the PIP if it is producing the pulse? I understand the PIP produces the spark and the fuel injector pulse, right? I am getting spark but no pulse... BTW Kudos on your 5.0 contents, very informative... (blink light on the test light on the coil negative is the pulse) just seen the whole video, lol

[@dragradialperformance3540]

@@driversinc yes, there is. You can backprobe the top wire on the ignition module harness connector with a T-pin or backprobe. Then use an LED test light clamped to battery negative, and touch the test light tip to the T-pin or backprobe. Have someone crank the car. The PIP signal is a 12v squarewave, so every time the signal goes high, your test light will blink the bulb. You should get 4 blinks per 1 revolution of the crank, so it's a fairly constant blinking while cranking. The PIP signal is used to fire the coil and the injectors. However, the coil can be fired by the ignition module without a PCM. The injectors can only be fired by the PCM. So if you have spark, you don't have a PIP sensor problem. But if you also don't have injector pulse, you do have a PCM problem. Confirm the PCM is getting powered up and is functional. See if the fuel pump runs for 1 second after turning the key on. See if the TPS sensor has 5 volts on one of it's 3 wires when you turn the key on.

[@robertjackson2012]

Great video on how to test. But what about the fix? I have a 95 f150 with 5.0 and have no injector pulse. Have spark, have fuel pressure. Injectors not firing. Is that a pcm issue?

[@Pontisteve]

If you have spark, you should also have injector pulse. The PIP sensor sends the signal to the PCM, which fires both coil and injectors off that same signal. Check to see if the red injector wire has 12+ volts with key on. Also check other injectors to see if they have ground/control pulse.

[@robertjackson2012]

@@Pontisteve I have spark all day long. Just no pulse to fire injectors. Wondering if its ecm or possibly crank sensor.

[@Pontisteve]

@@robertjackson2012 The PIP sensor is in charge of both injector pulse and spark. Same signal is used for both. Other than a bad PCM, the only thing I can think of is injector fuse (lack of power). If it was one injector, I have much more ideas than this. But all injectors? I would be looking at power the hardest.

[@robertjackson2012]

@@Pontisteve I have power at all injectors, just tested crank sensor it's good. I have no ground pulse to injectors. None of the fuses are labeled so it's a shot in the dark until find it.

[@Pontisteve]

@@robertjackson2012 The PIP sensor in the distributor sends a pulse signal to the PCM. 4 pulses per one revolution of the crank. You can see that pulse by backprobing the top wire on the ignition module, and touching an LED test light to it while cranking. The PCM receives this signal and fires 4 injectors per revolution. Make sure you test more than just 1 injector. The ignition system actually doesn't even need the PCM to fire. It does need the PIP sensor though. So a PCM problem, or lack of power/ground to the PCM could certainly be the cause of this. Maybe check PCM capacitors.

[@chicago701]

What is the pulse?

[@dragradialperformance3540]

Injector pulse. It's a ground pulse coming from the engine computer, and it's how the PCM turns the injectors on. They're only on for a few thousandths of a second at a time, so we refer to that as a pulse because of it's short on-time.

[@danieledwards6944]

My TV is still hooked to throttle body cruising about 65 just saying slipping anything I should look for

[@dragradialperformance3540]

Make sure there is no slack between the TV cable and the throttle body. There is supposed to be a plastic bushing there that takes up all the gap. It fails, and can cause the transmission to go bad. Replace that plastic bushing with an aluminum bushing.

[@danieledwards6944]

That's there but when it did happen I pulled over and I hit the throttle body Cable in that TV Locker cable and I heard at like like it relieves release some pressure but I've never had problems with this slipping before when I first bought it I had problems with his slip into the first so I did mess with it I mess with the idle screw the day before that I didn't think anything about it so how do I set it back to where it I did idle reset yesterday now if I'm standing there and I done all that yesterday if I pull the TV cable out of the throttle body is where it's supposed to hook up to the throttle body supposed to be a little bit ahead of it or behind in to the throttle body or is there any other kind of transmission I could use if I have to go another route like out of the LTD Crown Victoria one of the older ones or just has to be a Mustang one

[@train4905]

Awsome😊

[@chrish-4142]

I have 2 red wires going to every injector. Now what?.

[@dragradialperformance3540]

That's not stock, somebody has rewired something. With the key on, unplug an injector and test for voltage on both terminals. The one with 12v is the power wire. Mark the other wire with tape or something. The one that isn't power is the control wire.

[@quarter_-yl2uu]

I get no power to the coil negative.isthis bad tfi?

[@Pontisteve]

If you turn the key on, hook a test light to battery negative, and then touch the test light to the side of the coil with the red wire, the test light should light indicating power is going to the coil (from the ignition switch). You should also be able to test the other terminal on the coil (coil negative), and also have a light that lights. If one lights and the other doesn't, the coil's primary windings are open.

[@quarter_-yl2uu]

@@Pontisteve thanks. Got a new coil it has spark now. Still no start car has been sitting for years it got dark n I noticed the plug boots are letting the spark out I'm gonna change the wires today hopefully it will start then. As of now it will crank and cut off n abt 4sec. Then won't start again unless I wait a few hours

[@Pontisteve]

@@quarter_-yl2uu Sitting for years, I would bank on it needing a new fuel pump. Check fuel pressure. Should be 39 PSI key on engine off. If not that, it's also possible the injectors are stuck closed. You might try tapping on them with a wood pole to see if they unstick. Or listening to them with a stethoscope.

[@quarter_-yl2uu]

@@Pontisteve well I tested a few things on a buddy's car my dizzy is good tfi is new ccrm good new coil new plug wires new fuel filter ecm is good. Crunk it up ran for abt 8sec n shut off n won't start BK as of now. Just checked fuel pressure it is only 36psi with key on. Gonna grab a new pump this weekend n hopefully it'll run. Also it's a 95 car not a fox but I don't think that matters

[@quarter_-yl2uu]

@@Pontisteve also just tried start fluid and still no crank but if I wait till morning it will crank for a few seconds on first bump..

[@summerfox9292]

Good video my man. Question, where do you connect your hand held starter. Thanks

[@dragradialperformance3540]

The starter bumper? It connects to each of the two large studs on the starter solenoid, which is on the driver's inner fender.

[@summerfox9292]

@@dragradialperformance3540 awesome, thanks. That's gonna help me trace my #8 injector is not firing

[@dragradialperformance3540]

@@summerfox9292 Check that injector's red wire for 12v key on. Check resistance on the injector, unplugged. Should be 11 to 16 ohms, or more importantly it should be identical to the other injectors, within 0.2 ohms. And then check for injector pulse with an LED test light or NOID light. If you are sure you're not getting injector pulse at the injector, the next step would be to check that same injector control wire at the computer. If you get injector pulse at the computer, but don't get it at the injector, check your 10-pin connectors and do the 10-pin connector fix. I have a video or two on that. In fact, if you haven't already done it, do the 10-pin connector fix anyway, on all Fox bodies.

[@summerfox9292]

@@dragradialperformance3540 thank you much for your help

[@dragradialperformance3540]

@@summerfox9292 you're welcome. Did you get it figured out?

[@frankwoodman7901]

Control side of test light should be on battery postive not body ground thats why your test light was not getting a pulse

[@dragradialperformance3540]

The reason I wasn't getting injector pulse was because I removed the PCM, like I said in the video. But even if the pcm was installed and working, this layout still works fine. Notice the test light is lit up? It's because the power goes into the injector, winds thru the windings, comes out the other side, goes up the control wire, and back to the computer. So the control wire is hot all the time, unless the pcm ground pulses the injector. In that case, ground would exist on both sides of the test light, and the light would go out. The difference between the basic test method you describe and my method is that I can see if there is 12v present on the power side, and see if the windings of the injector are broke, and see if there is injector pulse... all in one test. Your test method would only show injector pulse. Both tests will identify injector pulse, but this method gives you more information. Got it? Try it on a healthy car and see for yourself!

[@dayntubee]

5:10 . How are you expect a computer ground the injector when you already unplugged the computer? 🤔

[@Pontisteve]

At that point in the video, I'm showing you what it looks like when you are missing injector pulse. And I tell you that the computer is not in there, so there is no injector pulse.

[@leobuck2060]

@@Pontisteve so you unplugged computer for demo purposes and that was a healthy engine?

[@Pontisteve]

@@leobuck2060 I did unplug the PCM to show that you can have spark without any PCM interaction at all. But injector pulse does require the PCM.

[@iamgriff]

Managed to make a two minute video a 8 minute video with all of that unnecessary dialoug

[@swizzynumber1]

Attention span of a squirrel

[@ICT_Anton]

Totally agree

[@dragradialperformance3540]

These are educational videos, not instructional videos. They're there to teach people how all this stuff works, not to save you time. You want the cliff notes? Check for injector pulse and spark using the appropriate test lights. Done.

[@iamgriff]

@@dragradialperformance3540 it took you 10 months to come up with that? No wonder this video in unnecessarily long

[@ramongalaz6263]

I found a partial problem.I got the engine running spark and injector pulse. Found that the starter solenoid s terminal wire will make the engine run when i jump it direct from the battery but when i hook the s terminal wire back it will only crank no spark or injector pulse.But there is a signal with 12 volt coming from ignition switch.Any ideas please and thank you.

[@dragradialperformance3540]

The S wire shouldn't have anything to do with the PCM operation, unless I'm missing something. That should just be a 12v start signal coming from the ignition switch, and going to the starter relay. Are you sure that wire is what you think it is, and that it's hooked up to the right terminal on the starter relay? The S wire should not affect PCM operation, unless the wire is shorted to other wires in the harness or something.

[@ramongalaz6263]

Thank you very much for your help. Traced it to transmission neutral switch. Ignition switch wire coming red/blue goes to s terminal at relay switch but splices off to transmission safet switch.Started right up