Old School 1995 ford f 150 5.8 litre- EEC- Fuel pump and ignition Diagnostics analysis confirmation and labscope setup verification questions

Hey, good morning all, after a very frustrating evening that i would've hoped to have been a very quick and easy diagnosis after i got in my own personal truck to go home this evening and turned the key only to find out... of course crank...crank, no start.  here's what i know. I finally have purchased my launch pad 7 elite which in this case makes no difference however i've had a fluke labscope that when i bought i was unaware i was buying from a seller that had sold it because it didn't work. now i have the launch o2-2 scope. pretty sure its just like the "hantek" but any advice upon setting up the primary initial BNC connectors and to which wires, i don't need detailed circuits just a general ideal i've taken the class. i guess i just want reassurance that i'm not going to ruin my new scope. My goal. i want to see if i'm getting crank signal and id like to match that up on the scope accordingly. My next inquiry is with the fuel pump. with this being a 95 f 150 5.8, i believe the crank signal must be seen by the pcm ignition control module for the spout and fuel pump to stay running? i may be completely wrong on this.  but otherwise the regulator drains the unused fuel back to the tanks. your guys wisdom is much appreciated! thank you so very much. I am getting spark, previous to this truck was losing power  right after a no start conditon, i had just replaced both front and rear fuel tanks and distributor, this was literally 4 weeks ago.
Chris Hobbs

Hey Hobbs, hope you're doing well!
Unfortunately, I have no experience with that scope and no real world experience troubleshooting advice regarding the old EEC IV Ford fuel injection system.
The only reason I'm chiming in here at all is because questions about that vintage truck seem to go unanswered or get very few responses and I don't want you think youre being ignored.
Someone may have some experience and advice to aid you on this one, but that system was pretty much dead and gone by the time I started learning diagnostics. For me, it's too old and if someone brought it to the shop, I would likely turn it away. I try my best to keep up with the cars coming through the shop today.
I hope you understand and I hope someone here can help you with what you're looking for!

This is your scope, right?

www.amazon.com/LAUNCH-Oscilloscope-O2-2-...izador/dp/B0C9D7J996

I haven't used that specific scope, but I wouldn't worry too much about damaging it. I've never known anyone to ruin a lab scope through normal (or abnormal) use.

My goal. i want to see if i'm getting crank signal and id like to match that up on the scope accordingly.

If you're going after the crank signal, I'd probably start at the Ignition Control Module. Charm.li has the OEM diagrams for reference:

charm.li/Ford/1995/F%20150%202WD%20Picku...m/Wiring%20Diagrams/

 

I'd start with two channels. One for the PIP at pin #1 at the ICM, the other for SPOUT at pin #2. Use the included backprobes. Scope ground to the B- post.

You could add a third trace with a secondary ignition pickup on the #1 spark plug wire for reference, if it helps. But, since it's a new tool and a new test, I'd encourage you to keep it simple for now.

My next inquiry is with the fuel pump. with this being a 95 f 150 5.8, i believe the crank signal must be seen by the pcm ignition control module for the spout and fuel pump to stay running? i may be completely wrong on this.  but otherwise the regulator drains the unused fuel back to the tanks.

The PCM has to see an engine speed signal in order to close the fuel pump relay, right. But it will also do a key on fuel pump prime, without any engine speed signal. Are you getting a key on pump prime?

Fuel draining back to the tanks wouldn't be related to the PCM, but is purely a mechanical function of a failing regulator or check valve in the fuel pump.

you are terrific man thank you so very much!! ok so to answer your question yes, i am getting a prime, however it is only about 5-7 psi. surely not enough to fire injectors? i am getting pulse signal at injectors and i have pulse sigal at coil secondary wire. im thinking ive misdiagnosed this all along. which is why i spent the money on my scope because i have he launch scanner i bought the launch o2-2 4 channel labscope to go with it, and yes that is the one you referred to. thank you again for your repsonse. also to throw another loop in this... my truck i purchased from a customer it has 300k on it and needed a trans rebuild... customer didnt like the price, so offered to sell it to me, its in great shape, so i bought it lol but it does say california on the sticker under hood but also says ferderal emissions. think thats confusing me as far as which diagrams to look up on mitchel do you know of how to verify this fact?

just as a verification to my first questions here... im really making sure that i understand this circuit and also of course my tool. so in this case i will not need attenuation as there are not high voltage, my probes are nice because the ones that were supplied came with red and black leads per channel. in the instructions it discusses grounding the whole scope itself which in and of itself is where all of my second guessing came from. but your saying its ok to simply connect red lead to the wire im testing and just ground the other wire? thanks in advance. im humbling myself here because i know this sounds silly but sure is different now not having guys in the bay next to you to go to for advise and your the only one in the shop running things:) Appreciate your and everyones knowledge and time.

 ok so to answer your question yes, i am getting a prime, however it is only about 5-7 psi. surely not enough to fire injectors?

Yeah that's way too low! Charm.li indicates fuel pressure should be 30-45 PSI.

i am getting pulse signal at injectors and i have pulse sigal at coil secondary wire.

Good! The presence of injector pulse would tend to suggest that the PCM is getting the engine speed signal, so you likely don't need to scope PIP and SPOUT.

so i bought it lol but it does say california on the sticker under hood but also says ferderal emissions. think thats confusing me as far as which diagrams to look up on mitchel do you know of how to verify this fact?

I'm not sure how to verify which emissions level it's at. RepairLink, maybe? I did notice that most of the OEM diagrams on Charm.li are annotated to show any differences with Cali emissions.

so in this case i will not need attenuation as there are not high voltage,

Correct. I didn't see a max input voltage in the user manual? But 200-300V is common. You won't be anywhere close to that unless you're testing primary ignition.

in the instructions it discusses grounding the whole scope itself which in and of itself is where all of my second guessing came from. but your saying its ok to simply connect red lead to the wire im testing and just ground the other wire?

Yeah, the manual is a little bit vague about making connections. This is the part you're referring to, right?

 

I wouldn't hesitate to go red lead to what you're measuring and black to B-. You can always try it on a known value first, just to get comfortable. A 12V battery, or a 5V sensor for example.

im humbling myself here because i know this sounds silly but sure is different now not having guys in the bay next to you to go to for advise and your the only one in the shop running things:) Appreciate your and everyones knowledge and time.

No worries! Helping each other is why we're here.

It’s very reassuring to me to have ffeedback and reassurance. Also had a traumatic brain injury so find myself having to really think and try to figure out something I know I was taught. I have always referenced Mitchel and Alldata for wiring diagrams and oem diag flowcharts but now it’s necessary for me to take the courses on here. I will be testing these circuits here momentarily and will update with the results. The pumps I had literally just replaced along with the distributor so I’m not exactly sure what is going on here when you say the relay closes when it sees engine speed are you talking about “faster than cranking”? I will repost with updates thanks