What a nightmare. I pulled my entire electrical system out on my car and it now lives on ping pong table as I go though it.

Wow
 

Thanks for all the great content here. Being a new RX7 owner, I now have a better understanding on what to look for when going through everything.

TM68

Wow, goodness gracious time has flown. Busy season is upon me in my main job, so working 6 days a week 10+ hour days limits time to get onto this beauty.

Working on a few items
- Was able to get the fuel pump turning through rewiring the main line for it. The last owner had a janky bypass on it for no reason. So am running stock lines but with proper connectors.
: Downside is that even with pump working the system fails to push fuel to the rails.
: Pulled main feed line no gas flow
: Used an air line to pressurize tank from cap location and received flow, went away when airflow ceased.
- Next step is to double check the lines configuration i have it in the pictures to ensure I do not have my feedback line in my inlet portion on the tank.
: Dropping the tank to pull the mechanism and check for issues in that area
- Additionally seeking to rewire the main ground and power on the battery as they used aluminum wiring

Will keep everyone posted as small victories are made.

......

Wooooo. Sorry for the lack of updates, the tank has been pulled. Lots of rust on the inside and the sock filter was/is completely clogged. Working on restoring the tank as we speak.
Also thinking of switching from a sock filter to inline prior to pump. If any issues please feel free to point out.
Anyways doing a first pass with the chemical evaporust, I used on parts with my last rx7 and did really well. Afterwards will do a full tank kit.
Meanwhile I plan on dropping lines into a gallon of gas to pressurized rest of system while tank is being fixed. Pictures to come.

Woo went full on brain fart today and attempted to feed my fuel lines using a gas can. Only after giving up have I realized the gas can needs to be about same height as gas tank in order to feed the pump...

Also found out my feed line to tank was old and had holes in it. Yet another reason it wouldn't feed after fuel pump install.
https://cimg3.ibsrv.net/gimg/www.rx7...e1aa49e6d4.jpg

Boy howdy we had some good progress today.

Was able to get fuel all the way to the rails
Found a couple loose fittings that I hadn't tightened all the way pressurize sprain ensued
Got her to turn over a couple times by herself with the fuel
A ton of gunk came out which is I assumed old fuel or something that was sitting in the engine like the oil I had in it earlier
Was not able to get it to idle just using fuel it ran like a kitten using starting fluid for a few seconds and intermittent spraying
Currently looking for ideas on next steps to get fuel to spray and consistently

Good news everyone! I have my brother in-law coming over tomorrow with an old rx7 buddy. Hopefully we will be able to diagnose and get it running. Will keep posting.

Subscribed!

Unfortunately this is not the case...

It's hard to really explain so excuse me while I try to make sense of it on paper.
Fuel injector is not activating from the distributor spinning. We listened with engine turning, nothing. Set enging to TDC removed distributor, turned manually, nothing. Check power at coil, one of the signal wires was at 1.4v instead of 12v. Followed wiring diagram/pin out for the ECU checked power to injector 1.4v so this tells me there is a short somewhere.
Pulled ECU and checked boards, one of the main large solder bubbles had broken. We resoldered the break and connected. Still at 1.4v. ran a direct wire from coil to ECU, shorted out to 1.4v again. so what this says to me is the ECU is shorting in one way or the other and cannot provide the signal to the injectors to fire.
next steps involve compression test to feasibilities of keeping engine and doing custom ECU setup
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Are you sure the ECU is grounded?

Was wondering the same thing, wondering if I shouldn't take apart the ECU, scrub the case and make some new brackets to attach on car for proper grounding. Or if there is a really goodway to ground the ECU that is not obvious???

Thanks you made me think more about that. Going to follow the write-up from Aaron cake on properly grounding a 13B ECU.
https://www.aaroncake.net/rx-7/grounding.htm

Hey everyone, just wanted to say I managed to source a 13b ECU from a couple states away for under $40.00 so I went for it. Wouldn't be the worst thing to have a spare of it turned out to be grounding. Should be arriving Tuesday, and hopefully testing on Wednesday

Evening, so my state is now requiring shelter in place for covid virus. May have a few more free moments to get the ol girl running

Hey fellow rotary heads. I don't know who is still following but I am chasing a wild lead on my coils going bad and causing lack of proper grounding for the ecu wire.
recap
Decided to try a new end to the coil, old was barely hanging in
Cleaned the mounting spots
Moved the ground for the coil
Have two new coils coming to test. Just economy as I simply trying to get the injectors to fire
replacing (m6?) bolts to grounds

Standby for arrival on coils on the 30th to try the changes for injector fire

Ignition coils? Test them. Remove all wires from coils and use an ohmeter set on 200 ohm scale. Connect test leads to positive and negative primary terminals. Should show 1-3 ohms,what do you get? Switch ohmeter to 20k ohms scale,put one test lead down hi tension tower to coil wire terminal(where coil wire goes)and other to either primary ignition coil terminal. Should show 5k-8k ohms,what do you get? Post results here.

Original Diamond ignition coils that came on car are very good quality,better than what you can buy new now. If your test results are within specs listed above,your coils are good.

Ignition coils are NOT to be grounded. What wire are you grounding? Pics?

Thanks for the information. Maybe I followed my ground wrong but it looks like my negative terminal on coil to front of car is leading to a ground mounted on the strut tower that is also housing battery and starter grounds as well.
Have a black wire with yellow stripe going to this ground same as wire coming from coil so I could use my multimeter to test this as well correct?

Yep yep totally my fault I followed the ground wrong and I just saw that come out and I realized by looking at my acquiring that it's actually going to the correct spot on the ignition control module which is on the dizzy my bad

Have you tested your ignition coils yet to the test specs given. Start there and eliminate them as contributor to your problem.
Highly doubtful coils are defective.
Post results here

https://cimg5.ibsrv.net/gimg/www.rx7...1636145fe8.jpg
Top view
https://cimg9.ibsrv.net/gimg/www.rx7...e997dee008.jpg
The wire added
https://cimg2.ibsrv.net/gimg/www.rx7...837d8969f5.jpg
ok so the wire with the butt connector, is my understanding it should supply 12v to ECU.
Used to be full wire but was not long enough to redo the end which was barely hanging in.
anyways when connected where it is the connection goes from 12v+ to about 1.4v.
Ideas? I am chasing ecu grounds currently

That is incorrect,that black wire is the rpm signal wire that goes to ecu and is used partly to determine when to fire injectors. The reason that wire is pulled down to 1.4 volts is because the ignitor is switching power to the coil.
The coil wires are as such...

Trailing (front coil) primary positive feed is black/yellow and negative terminal has yellow/green return wire from trailing ignitor that splits further up in loom and provides trigger for fuel pump relay and rpm feed for dash tachometer and black rpm signal wire going to ecu.
Leading(rear) ignition coil positive feed is black/yellow and negative terminal has yellow/blue return from leading ignitor.

Understood you're chasing grounds. I'm willing to work with you to help you figure out the reason(s) for the no start. You"ll need to take some direction. 1st thing i need you to do is stop chasing grounds and test the ignition coils as i outlined in a prior post. I am somewhat familiar with these cars and will show you how to test components and wiring to eliminate cause(s) of no start one by one til you have a running car.

Hey I super appreciate the help

Trailing results
1.5 ohm
7.5k
​​​​​​​
Leading results
1.9
7.3k

Those coils(in the car?) test fine. Will get back to you in a bit.

What spark plugs do you have in the car?