I never test a coil with an ohmmeter. If the coil is bad enough, an ohmmeter could catch it. But if the ohmmeter says the coil is perfectly within specs, that doesn't mean the coil is good. The reason is the coil heats up a lot when actually being used. And so while the ohm tests may be accurate when the coil is cold, the coil could quickly warm up and no longer be any good. An ohmmeter is just not a good test for coils. Instead, check for constant power on the red wire, under a small load. And check for ground pulse as shown in this video. Then load test the output of the coil by slowly increasing the gap of your spark tester. A good coil will fire a bluish purple spark over an inch. A weak coil will be a yellow spark that can't go much more than 1/2". A bad coil won't fire at all.

@@dragradialperformance3540 sorry meant the connector positive to the distributor coming from engine harness . The negative on my distributor completely fryed , so when probing the positive pin 1 and 5 I got 47 ohms with the distributor disconnected on run command from ignition switch

Only time it reads zero from pin 1 to ground is when I remove ip fuse 18 under the dash

@@raulh802 Do I understand it that you're ohming power wires? There's just no reason to, and whenever you ohm something, it has to be disconnected. Ohming wires and coils is nearly worthless (except airbag wiring, or when checking for a short to ground). The ohm meter is best used for measuring resistance in solenoids. For everything else, stick with measuring voltage. Or in some cases, amperage. If you're saying the negative WIRE going from the TFI module to the coil has literally fried, then it's shorting straight to power some how. That could be a dead shorted coil, or a short to power in the coil control wire. When you say pin 5, can I assume that means you're measuring stuff at the TFI module connector? Again, stick with voltage, or pulse testing.

@@dragradialperformance3540 The plug that connects into the distrubutor is what i was checking. it comes off the injector harness and has a radio supression capicitor on the same electrical point. That female plug has 7 pins pin 1 is power to that pin along with coil positive , pin 5 ground and tfi module. My module is in a remote area not like the fox. With the engine off and checking resistance fom pin 1 to ground it has resistance of 47 ohms almost as if it was shorting. being that the ground wire to the distrubutor is smaller gauge , i thought that is wahy it would burn up before the thicker red wire. I was trying to find the source of the ground fault.

If you have coil control (ground pulse) from the TFI module, then you're not worried about the PIP Sensor signal or the TFI module. If you also have Injector pulse, then you aren't worried about the PCM. But that should be checked, because the TFI module can fire the coil with just a PIP signal, even without a computer installed. The coil still needs to be checked for power coming in on the red wire. That same power is what is showing up as a lighted test light on the coil control wire, as shown in this video. If you have power on the red wire constantly during cranking, and coil control on the negative side, then the coil should be producing sparks. Check that the coil wire to the cap has a spark in it during cranking, using an online spark tester, or an HEI spark tester. If no spark despite good coil power and good coil control, then the coil is bad.

It doesn't really sound like a bad TFI to me if the other 7 cylinders fire fine. I've not seen this issue before. Are you sure that's what's happening? The TFI module fires the coil every time it gets either a PIP signal from the pickup coil in the distributor, or a SPOUT signal from the PCM (if the SPOUT connector is plugged in). Try that test with the SPOUT connector plugged in, and also unplugged. If it's a PCM issue, you'll have all 8 sparks if the SPOUT connector is unplugged. If it's not a PCM issue, it's probably an issue with the stator inside the distributor. It has 8 teeth, one skinny and the rest wide. Make sure not of them are missing or bent. Also make sure the cap points look fine.

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).

Try unplugging the SPOUT connector. That takes the PCM out of the equation, and the ignition module fires the coil based solely on the PIP signal. See if it starts that way. If not, you'll have to check the PIP signal, preferably with an LED test light. I believe I have a video showing that. It's the top wire on your ignition module connector. Also, try unplugging the coil and hooking a test light to battery positive, then touching the yellow/green wire (key on). See if it lights the test light (by providing a ground to it, since it's already hooked up to 12v power). If the light lights up, there may be a short to ground in that coil ground wire. If so, it would energize the coil non-stop, and blow up every coil you install.

The coil inside is basically one wire, coiled around an iron core. Every wire has 2 ends. When the coil is not grounded, power basically just goes in one end and comes out the other. So 12v in and 12v out. It's not until you power one end and ground the other that the coil charges. Which means you should have 12v on coil negative, until the ignition module grounds that tan wire. If you don't, test it again with the tan wire disconnected, or ohm test the unplugged coil on those two terminals, to make sure the coil primary windings aren't broken and open.

Lots of early 90s capacitors seemed to start going bad about 15 years into their life, it's a plague in the retro video game system community.

Don't be so sure. It's a 4-layer cake, so two internal layers of traces you can't see, and the back side of the board has components all over it too. They are older and more spread out than modern PCMs though, with a lot less stuff and no ball sockets. I built that bench test setup using an old Ford EEC-IV PCM for a case, and polished the lid up just to be cool. It works great for basic bench testing.

​@@dragradialperformance3540oh god, does that mean 2000s cars have the shitty solder that plagued the entire tech industry too?

@@Wheagg I sure hope not! I think it's possible around 2007-up that maybe California wants that. But I so far haven't seen any evidence of ROHS in that era. Just documents talking about it from CA.

I'm not familiar with the older Dodge computers. But any computer that has electrolytic capacitors in them that is over 20 years old would be highly recommended for replacing the capacitors BEFORE they leak. They are about the only part inside that has a shelf life. Everything else just works until it doesn't. These die of age, regardless of care or mileage. Computers that are under the hood are usually sealed up with some sort of rubbery type gasket material. Computers installed inside the vehicle don't need to be waterproof, and so they may not seal them at all. That's how this 94 is, unsealed and very easy to take apart. Professionals who repair PCMs regularly will heat up the computer and carefully cut or pry apart the rubber seal to get it apart without damaging the PCM. After it's apart and repaired, they clean all that rubber off and replace it with something similar, or maybe even just silicone. I don't know if the older Dodge PCMs have electrolytic capacitors in them. But if they do, they should be replaced based on age alone. We're seeing 94-95 Fords now coming in with capacitor issues, and have been seeing 87-93 Ford PCMs come in for many years now. So your 92, if it has capacitors, is the right age (or late) to replace them. Everything else in the PCM is not in need of refreshing or upgrading, just the capacitors. We only do the Ford computers, but I can probably turn you on to some smart guys who do the Dodges, if you can find out that your PCM has capacitors in it. A lot of the pre-96 era stuff does.

@@dragradialperformance3540 thank you for taking the time to write me a nice response I have some research to do then to find out if I have those capacitors. I do put a lot of trust in this vehicle my wife also daily drives a 92 Cherokee we really like Cherokees and it just so happens we like the 92 models I've had almost every year of Cherokee xj but the ones we have kept and really like is the 92s or 91-95 really is what I tend to stick with. But anyways I'm going to do some research and see if I can figure out more about the ECM. My cherokee is very heavily modified I've rebuilt most of the harness with mil spec wire that was a fun project a little tough to find some of the contacts for the OEM plugs. I could have gone with an aftermarket computer and stuff but I've done some things and added some stuff to get more out of the stock systems and I just like having the stock control modules I'm running a piggyback setup on the transmission control module to do some neat things in conjunction with some transmission mods but I also retain all the stock functions. Then I'm running a stroker engine with some things to make it all work with the stock ECM it's actually been very reliable I've played with these jeeps for so many years that I've kinda figured out what's best for reliability and modifications sometimes you don't always get reliability with modifications. Then I have access to diagnostics for the transmission and engine module even some live data with my snap on mt2500 you probably are familiar with that since you work on the pre obd2 Ford's. I'm a bit of a nerd when it comes to my gadgets and playing around with these jeeps. I've never seen a Cherokee pre obd2 module fail except for I have seen the voltage regulation fail which is controlled by the ECM you can replace the ECM or set up an aftermarket regulator to correct the problem. I really like the idea of having someone freshen up a module or two for me if it has capacitors, I'm definitely going to learn more about their construction. We plan on driving our Cherokees and others for a long time to come. Thanks again for the information I'm excited to learn more about it.

@@dragradialperformance3540 here's a short little video linked below of the ECM I have. it looks like it does have capacitors from the little bit of research I've done. I actually was reading some reviews on capacitor kits available for the ECM and one review said that he had a computer repair shop installed them and it works great. My ECM is coated with that rubber stuff as it's under the hood. I still want to look into it more but I wanted to add this 2 minute video I found that shows what my jeep ECM looks like. Ideally I'd like to find someone who is familiar with control modules and knows what the best parts are to use like the best brand or type of capacitors if that matters. I'd just like it done as best as possible if I'm going to do it and it should also be sealed back up well afterwards because my jeep sees some nasty conditions sometimes. I'm actually kinda surprised I've never experienced any problems because there's tons of stuff about capacitor failure when I Google search. kzbin.info/www/bejne/gJ3ceJ6Jdqp0rKcsi=I1fSLbIZd4TlSvM2

@@forreststrong797 yes, that's them! Look into Nichicon capacitors. They're high quality Japanese capacitors, and it looks like those are the ones used by Jeep, as well as our Fords.

What, replacing the capacitors? It does if you know what you're doing. It's not really a DIY job. Does a Jeep pcm that new still have electrolytic capacitors?

You can email me at [email protected].

When you unplug the SPOUT connector, you are eliminating computer control of timing, and the ignition module instead fires the coil at a fixed timing value every time. That value is set by you, and should be 10 degrees BTDC. Plugging SPOUT back in let's the computer control the timing, but as soon as you unplug it again, it should be rock solid at 10 degrees BTDC again. Unless you are using your timing light wrong or it's defective, the only way the timing can chance with SPOUT unplugged is if the distributor bolt is loose, there's something defective inside the distributor (like a broken rotor or rotor plate), or your harmonic balancer is really bad. The balancer has inner hub that bolts to the crank, and an outer hub that is presses onto the inner hub with a piece of rubber strip in between. When this rubber gets really old and bad, the outer hub can slip on the inner hub, moving the timing mark. Actual timing doesn't move, but the timing mark does. You can check the accuracy of the timing mark on the balancer using a brass piston stop in cyl #1 plug hole, and rotating the motor both directions until it hits the piston stop at about 10 degrees before and after TDC.

@@Pontisteve Thank you for responding. I did a water pump change and the balancer was ok, I thought the same thing at first but I’m still having the same issue. I will recheck the rotor and plate again. I marked the balancer and set it at 10 degrees BTDC and plugged the spout connector back in and it seemed to drive fine. The crazy part is, the next day when the engine was cold the car had a rough idle and when I took it out for a ride, the engine started stumbling and had lack of power so I checked the timing again and it wasn’t at 10 degrees, it was jumping between 12 to 40, so this one has me confused lol. I did new plugs, wires and rotor cap. I didn’t change the Ignition Control Module so I was thinking it’s bad and not sending the correct signal out. Not sure why it’s not holding timing to be honest. I really don’t want to throw money at it without knowing the exact issue. But I will check it with a different timing light and go from there. Thank you for the advice I appreciate it.

@@sheba6779 You're only checking timing with the SPOUT connector removed, correct? Because with SPOUT plugged in, timing will be moving all over the place, especially at idle. Unplugged, it should be 10 BTDC at all times. Plugged in, idle is centered around 20 degrees BTDC in the computer's commands, but will move several degrees in either direction of that to perfect idle quality. The worse the car is running (for some other reason), the more timing the computer will add or subtract from that centerline of 20 at idle.

Flash programming did not start until 1996. These older computers can be custom tuned, but they require an actual chip to be burned, and inserted into the back side of the computer.

I built it myself.

@@dragradialperformance3540 how much would you charge to build one for me? We tune a lot of foxes, sadly a lot of them come in with dead ecu, always blaming the tuner when their car don't want to get tuned lol

​@shangman4240 email me at [email protected] and I'll give you the current pricing and shipping info.

The zip tie goes thru factory holes in the door metal. See 5:40 into the video.

You usually do not need to use a standalone computer for most cars making under 700 HP and turning less than 7000 RPM. If you want to use a standalone PCM, check into Holley and MegaSquirt. You can usually use the factory PCM, if it works well. A chip can be built that custom tunes the PCM for just about any modifications necessary. You're welcome to email me details about your project and computer, and I'll see what I think about what you need. My email address is [email protected].

You can email us at [email protected] for pricing and instructions.

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.

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

@@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).

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

That's because I already fixed the issue before making this video. I repeated the whole process on film just so people like you could see how to do it. Is lifting the window that difficult to envision?

I appreciate the step by step. My window has been held up by. taping it, worthless. I saw this video which is perfect for the temporary fix. The only thing I couldn’t see was where you tied the ties behind the speakers by the window to hold up the window. I’m not planning on purchasing anything new for this car. All easy & temporary fixes for little jobs from here on out. It’s not worth it anymore. Too many things going wrong all at same time. Thank you~😊

@@peg7997 tape never works long, and damages the paint if it's on there very long. This fix is much better, and can be fairly permanent if you don't want to buy a new window regulator and just want it up all the time. Look at time stamp 6:10 to see where I put the zip ties thru the window regulator.

If you use an incandescent test light, or an inline spark tester with adjustable gap like the Lisle tool, you can slowly increase the gap that the spark jumps from 1/4" to about 1". The spark should easily jump the gap that far, and the spark should be a bluish purple. A consistently yellow spark that struggles to jump a 3/4 to 1" gap is a weak coil. Confirm the coil has a good 12v power going to it, and replace the coil with a genuine Motorcraft.

The idea is to get a really light, even film of thermal transfer paste between the module and the distributor pad. Sanding the pad flat is better. And high quality thermal transfer paste (often made for home PC chip installation) helps dissipate the heat better. You can also buy kits that relocate the module off of the distributor. That's what Ford did in 94 to fix the module deaths that older Fords are known for.

@@dragradialperformance3540 Problem with those kits is they involved screwing around with wires. That's something I'm simply not comfortable with. Now, my current module only caused one stall on a cool evening. Do you think it's safe to just pull it, clean it, apply the paste better, and try it again or do I need to buy yet another?

@@JRC99 when the module isn't installed correctly and overheats, it cooks the module. It probably wouldn't work at all because of heat. Chances are if your new module is acting up, it's probably just a factory defect. These new modules are all junk, compared to the original Motorcraft ones. I've had to put 3 or 4 in a row on a car just to get a good new one. So yeah, feel free to pull your module and reinstall it as shown in the video. The video makes the module paste look much thicker than it really is. Spread it as thin as possible, while still having a complete thin layer across the entire module. None should squeeze out when tightening the module.

@@dragradialperformance3540 Interesting. Both my new Motor craft modules worked again after the car sat for a few minutes. Even the first one I put no paste on and that was on a 95 degree day. So if I understand you correctly, both of them are still good?

@@JRC99 I can't say that one way or the other. It is terribly complex to actually test an ignition module. It requires a scope. The module gets hot quickly, and can easily act differently because of temperature. I've had some that wouldn't start, but if it did start it would run good. Others ran fine at idle, and broke up at high RPM. Others just did not work. The new Ford ones aren't any better than the cheap chinese junk. You can watch my videos on me testing a module with a scope, to see what I'm talking about. It's not easy to truly test one. For most people, it's easier to just try different modules and see if the car runs differently. You can not assume that the first new module you put in a car will be good out of the box. It's like russian roulette.

The red/light green wire should have 12v on it any time the key is on. This comes from the ignition switch (in the START or RUN position, then goes thru Fuse Link N (that may vary depending on what year car it is), and then it goes to a splice, which goes to both the ignition coil and the EEC power relay. Test this wire with an incandescent test light that's grounded to battery negative. This light should remain bright at all times, even when cranking. If not, find out why. Maybe you have a half melted fusible link. The other wire will have a ground pulse on it during cranking. When not cranking, 12v will come from the red wire, thru the coil windings, and out the other side onto the tan/yellow wire (or whatever color your coil ground wire is). If you don't have power on the red/light green wire, then you wouldn't see that power coming thru the windings of a coil when the key is on and engine is off, indicating the red wire doesn't have power.

Changing out your whole EFI goes beyond the scope of what I can cover here. But assuming it uses the stock TFI system, then we should be able to treat it like a stock car. The PIP Sensor tells the TFI module when to fire both the coil and the injectors. So checking for Injector pulse during cranking tells you if you have a PIP signal or not. You can also test for PIP directly, at the ignition module. It's the top wire on the TFI connector. Backprobe it, and use an LED test light hooked to batt negative. Look for the light to blink as you crank it. If you have PIP, you should have coil control (negative pulses from the TFI module to the negative side of the coil). You would also have a fuel pump that turns on for 1 second if you bump the starter a little. If no spark, then either the module or the coil isn't working. Test for co control and coil negative to see if you have the pulse, like this video talks about. If you have coil control and no spark, and if the coil has 12v on the positive side, then the coil is bad. If you don't have coil control, but do have PIP, then the TFI module is bad. The PCM doesn't even need to be installed for the spark tests to work.

That is correct

This is what the video is for. I have other videos on testing the coil as well. Remember though, that these Mustangs can have spark even if there is no computer installed at all. The pickup coil has to send a signal to the module, and the TFI module fires the coil by ground pulsing it. It's rare, but possible, that he pickup coil is bad. It's more common that the TFI module is bad. But you have to test to be sure. Could also be lack of power or ground going to the module. I recommend testing, not guessing. But if I were guessing, I would say no spark = a bad TFI module. See video on how to properly install a new module. If you want to replace both at the same time, just put a reman distributor in it that comes with both a new PIP sensor and module. Getting quality new modules is a PROBLEM. Even the Ford module is now just a cheap Chinese module. Only the original Ford modules with the word Motorcraft embossed into the module plastic are good. The rest are cheap chinese garbage, in my opinion.

@@dragradialperformance3540 ty I appreciate you getting back to me . what worries me is no fuel pump . No prime when key is turned on . I have checked power at Borg sides of all fusible links . And I have heard that the check engine light should come on with key on engine off .but I have never seen a check engine light on my dash . And I agree about the cheep china parts . because I have changed the pickup and module a few years ago when I changed the distributor gear . I have already bypassed the inertha switch a few years ago when car wouldn't start. I'm sure I will figure it out but I don't want to throw parts at it and don't have much for testing equipment . Going to test all relays and then start with tfi module . Ty again

​@jaymartin5434 no check engine light ever coming on likely means the bulb is bad, or maybe someone removed it. Replace the bulb. No fuel pump prime means either the PCM is not getting power, or ground, or the capacitors in the PCM are shot. The capacitor theory is very likely. All these 95 and older PCMs are suffering from this because they're the right age for it. Remove the PCM, take the lid off, and look at the 3 teal blue capacitors. If they are leaking at all, they're bad. This can cause the engine to run rough or the PCM to not work at all. Very likely! In ALL foxes, these should be checked. And if the original teal blue capacitors are still in there, they should be replaced by an electronics repair pro. We offer tbis service. Avoid those jackleg Ebay "PCM repair" services". They suck.

@@dragradialperformance3540 ok so it was the ECM relay . I had a windshield put in just before I parked it for the winter and when I took relay out it was wet . I jumped the two big connectors and it started but I still don't hear pump do ten second primi . But it has always started right up . pump is quiet and that damn factory fan makes so much noise. When car is running .. I did remove the ECM that was in car before I tried jumping wires because it was damn feeling .. I'm not sure yet if it was got wet inside . going to take it apart and look it over . . I'm going to change my ECM relay and fuel pump relay . And maybe the one under the hood on right side of car . Ty for your input ..

​@jaymartin5434 glad you got it figured out. ECM relay failure is unusual, and it should never be wet. Check for windshield leaks. The capacitors should still be checked. They're bad based on age alone.

Both of those codes indicate there's a problem with the voltage on those sensors, probably voltage too low. Usually, that means there's a broken wire. That TPS sensor should have one wire with 5v on it (key on), one wire with 1 volt (the signal wire is about a volt at idle), and one wire that's a good ground. Test all 3 to see which of those wires is not correct. That will lead you to the cause of that code, and it's likely the other sensor has the same problem source. While it could be a PCM issue, I doubt it is.

That's great news, Bill! Thanks for letting us know. See you next time!

I wanted to ask your opinion on something, can these modules affect idle? lets say you have a really nice OEM module versus the china crap,could you notice any improvement by swapping them out if you are having issues? Ive been stranded before because of these damn things but i was under the impression they are either good or bad, no in between, guess Ive been wrong?

I've seen modules fail in different ways. Some break up at WOT. Some won't start. Some will idle poorly. So there doesn't seem to be any specific issue you can correlate to the module failing. Without a scope, all I can say is if you have unexplained misfiring or a no-start, it could be the module. Only with a scope on PIP, SPOUT, and the Coil Control wire can you really see that the module is being told to fire, and then doesn't. No other tool is fast enough to catch single misfire events.

We offer capacitor replacement service on most older Fords. Often that fixes them. But beyond that, we don't do any other repairs.

I don't have any information about an XOX or X0X calibration. What is the part#? (xxxx-12A650-xx)?

F0ZF-12A650-CA

@@AliAli-hm2np From what I can tell, this is a 1990 Ford Mustang computer for sure. And I think it's a 5.0L export model, possibly for an automatic transmission. I've heard this computer doesn't use any oxygen sensors at all, and runs in open loop. It would have been for models exported outside of the USA, such as Saudi Arabia.

Yeah it is in Saudi Arabia but are you sure i dosent run o2 sensor

I did install o2 sensor and connect it yo it

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.

What problem are you having? When you plug the SPOUT in, the computer becomes involved in altering timing. Unplugged, the pcm doesn't affect spark timing.

Surging fluctuating rpm = spout plug in Steady rpm steady timing =spout unplugged

Thank you for the comment my man. I needed to hear that. It inspires me to do more of that.

The ignition module is a prime suspect. The computer capacitors are worth inspecting too.

The red/light green wire should have a constant 12 volts on it when the key is on. This is the power side, and is constant hot. The other wire is the control wire. It's how the module controls the coil. The module grounds the coil for a few thousandths of a second. When it quits grounding it, the spark occurs. When the coil is not being charged, the 12v winds thru the coil and essentially shows up on both sides of the coil as a constant hot (light on). When the module grounds the coil, it very briefly drops the voltage on that light (5 thousandths of a second). That's what causes the flicker. There is a tiny amount of flicker caused by the starter drawing a bunch of amperage every time a piston comes up against compression. But there is a more pronounced flicker when the module is actually grounding the coil, or pulsing it. If the ground/control side of the coil flickers strongly, the module is grounding the coil and the coil SHOULD fire the spark. If the flicker is very light or not at all, then the module is not turning the coil on. It's best to just watch the video a few times and see what that difference between a normal starter flicker and a coil control looks like.

PIP sensor is checked using an LED test light on the PIP signal wire at the ignition module during cranking. Backprobe the PIP signal wire, put the test light in (or touch the tip to) the back probe. Ground the test light cable to battery positive. Crank the engine, and you should have a brief flash of the test light repeatedly during cranking. Usually the PIP signal wire is either the very top or very bottom wire on the module connector. The PIP signal is a brief 12v signal coming from the pickup coil in the distributor every time a cylinder comes up to bat (which is 4 times per crankshaft revolution). The PIP signal goes to the module, telling the module when to fire the coil. If the SPOUT connector is plugged in, then the PCM will modify the timing of the signal, otherwise it occurs at 10 BTDC every time. Either way, the PIP signal tells the module when to fire the coil. The module actually fires the coil by grounding it for a few thousandths of a second. When it quits grounding the coil, the coil fires a spark to the distributor cap, which disperses the spark to the appropriate cylinder.

I made it.

@@dragradialperformance3540 Do you have a video on how you made it and if not could you please. I am always dragging home vehicles of this vintage and would love to have this tool on hand

@@jldwolfeI don't have a video on that, and probably won't have time to make one any time soon. But I can describe it. 12v comes in from the power supply, thru the switch on the left, and out to the PCM's key-on power input. I tied the red LED into the other power wire, just to see voltage flow thru the internal power bus, as well as to indicate the thing is on. Orange LED goes to the MIL light wire. Green LED goes to the Fuel Pump relay control wire (FP). Switch on the right connects two wires together to get it to pull codes. I forget which two wires they are, but they're both on the OBD1 diagnostic connector. The voltmeter is wired up to VREF, and has 12v and ground coming from the power supply. It displays reference voltage (sensor power). The case is a rare, older EEC-IV PCM case, as I recall. I polished it just because I can. The PCM connector is a junkyard EEC-IV connector, with only the wires needed being hooked up.