1st Generation Specific (1979-1985) 1979-1985 Discussion including performance modifications and technical support sections

84 GSL-SE Won't Run

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Old 12-29-23, 09:17 AM
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84 GSL-SE Won't Run

Bought my 84 GSL-SE at a salvage yard. Only report was 'It won't start'.

Towed her home. She definitely starts, but she won't run.

Nice strong battery (had it tested), that I keep her on everyday.

Fixes / Repairs-

1. Oil change
2. Coolant change
3. New thermostat
4. New wires
5. New plugs
6. New fuel filter
7. New fuel pump
8. New ignition coils
9. New intake gasket
10. Cleaned and re-linned fuel tank
11. New fuel hoses
12. New fuses
​​​​13. Deflooded several times
14. Swapped out ECU
15. Took injectors to a shop to have tested and cleaned

I've tried starter fluid several times. Again, good strong crank just won't catch.

Any thoughts on what may be preventing her from running, or what to do next?

Last edited by Phineas; 12-29-23 at 10:37 AM.
Old 12-29-23, 10:35 AM
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New head gasket?

Have to check three things - spark, fuel, ignition. And, of course, compression.
Old 12-29-23, 03:41 PM
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Going from your list, you're still needing to check / replace Distributor Cap and Rotor (*basic tune up items), and Ignitors.

The SE gets it's injector pulse signal from the TRAILING ignition, specifically the Trailing Ignition Coil. This signal wire also tells the dash what RPM the engine is turning. If you've got no tech reading, you've got no Trailing Ignition, and you've also got no injector signal pulse to the ECU, so you're not getting fuel injection.

Simple test; swap Ignitors at the Distributor and see if you get tachometer and injection working, along with engine start and run. Another simple test; swap the Injection Trigger Signal wire from Trailing Coil spade to Leading Coil spade - this will fire injection off proper timing, but it will run. That will demonstrate a failed Trailing Ignitor or Coil.

Also, be sure to check and test the INJECTION Fusible link located at the DS strut tower, specific to the SE. If blown, the Injection system won't fire, obviously.

P.S. - all of this is available via search. Scroll down for some likely links from me and GSLSEforme over the years...

Last edited by LongDuck; 12-29-23 at 03:45 PM.
Old 12-30-23, 04:53 PM
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I hooked the fuel pump back up. Then I took a long screwdriver and used it to depress the accelerator I bit while I cranked.

Fired up and rolled over like a champ.

As long as I kept the pedal depressed just enough she ran.

The instant I released the accelerator beyond a certain point she died.

1. We know show runs.🤓
2. What is the issue now with not running at low rpms?
Old 12-30-23, 07:43 PM
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84SE-EGI helpy-helperton

 
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Why was the Fuel Pump unplugged?

As to the lack of idle, I expect vacuum leaks. Big ones.

Did you change the Distributor Cap and Rotor? How about testing the Ignitors? More info gets better suggestions...
Old 12-30-23, 09:00 PM
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Yes. Changed the entire distributor and ignitors. Cap was new.

Major rebuild. Taking it a piece at a time. Pump was unplugged because it was starting of gas and just flooding.

Tank was total trash. Had it flushed and re-lined. New pump, new filter.

Injectors cleaned and tested. New pulsation dampner.

Fuel pressure test within requirements.

Bought at salvage. No telling how long it sat.

Finally running. Smoking like a catholic priest, but it is finally running.

Only stays running with some accelerator. Without, it dies.

New plugs, wires, coils, conformed placement and installation of all vacuum hoses.
Old 12-31-23, 04:46 PM
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Got her running.

Strong crank, engine sounds good.

Won't stay running unless I'm on the accelerator at 3400 rpm plus; If I let up she stalls.

Video shows start.

Thoughts?

Old 12-31-23, 07:46 PM
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Sounds like a significant vacuum leak to me. When you first start it up, it has a shrill intake sound which might be coming from somewhere in the intake path. This would also account for your 3400rpm "idle" as at that RPM it will fool the ECU into thinking it needs more fuel as its in Open Loop operation as you have too much air getting past the Airflow Meter such that the ECU can't map it to a burnable mixture.

Places to look; the tubing between the Airflow Meter and the intake plenum, the RE-EGI chamber to the Upper Intake Manifold, Upper Intake Manifold to Lower Intake Manifold, and the Lower Intake Manifold to the engine. Take a close look at the Air Control Valve on the Lower Intake Manifold, as well. These all have fiber gaskets which can crack or deteriorate enough to allow air to get past the metering system.

Also, take a close look at the other attachments to the RE-EGI airbox; BACV and the tubes which bypass the chamber to feed it, along with the 5 vacuum tubes at the front of this chamber and the one below the BACV which everyone forgets about. They should all be connected to something. Look for the under hood sticker for routing.
Old 12-31-23, 09:07 PM
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Thank you for the detailed reply.

Confirmed all vacuum hoses (in accordance with the image), are propery attached and properly routed.

Also, tracked all large hoses in and out of intake to ensure they are connected and that clamps are applied, and they are connected and clamped.

During my work I did not touch the large hoses, and made sure I followed this image to reconnect the vacuum hoses.


Old 01-01-24, 02:48 PM
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Those small vacuum lines aren't bypassing nearly enough air to cause the symptoms you describe. I'm betting it's a gasket at one of the junctures I mentioned above that's cracked a section loose and has created an open air slot. Aside from that, you could also check the Air Flow Meter operation (*search on my name, as well) to check if the AFM is getting stuck with the Air door not moving freely and smoothly.

Based on your video alone, it sounds like a significant air leak to me.
Old 01-01-24, 04:17 PM
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Thank for the info.

Got her to start AND stay running.

Though the start idle is about 3500 rpm.

Old 01-02-24, 10:29 AM
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I too have a GSL-SE, which I rebuilt from the ground up as well. While I haven’t posted much on the forum I have found it invaluable over the years. Since I haven’t posted anything on here in at least a decade I’m not sure if I can even post my suggestions here.
Anyways as everyone has been saying your issue may be caused due to a massive air leak. If you want to check to see if it’s cause by an air leak I suggest starting the car and keep it running. Next take a propane torch that’s not lit but is still releasing propane. Slowly point the tip of the torch at all the vacuum tubes as well as all the other places mentioned above. If the idle increases then you’ll know where that leak is.
On the off chance that isn’t the problem might I suggest removing the throttle chamber and give it a through cleaning, removing any carbon buildup that may be plugging up the secondary air intake plate thus not allowing air to enter the Dynamic Chamber thus preventing the fuel injection system from working and preventing it from idling. The car is 40 years old and there’s a good chance it’s never been cleaned properly nor has it been serviced and lubricated.
If you have to push on the gas pedal in order for it to start then I’m guessing it’s a lack of air flow causing the problem. Especially if you’ve flooded it several times.
Once you have cleaned and lubed then try it again. If it’s still not idling after that then you’ll need to check and adjust your throttle positioning sensor and then it may be time to adjust the idle adjustment screw. Just a couple ideas.
Old 01-02-24, 02:55 PM
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Thank you for your extensive comments.

Current Status:
1. Cranks right up.
. 2. Cold start idles at 3500 rpm (no accelerator
from me)
3. I let it warm up this morning for about four
. minutes.
4. Oil pressure rested at about 60psi
. 5. Coolant temp climbed to idle temp when I
. turned it off. No sign of overheating, but I'd
need to let it run longer to know for sure.
6. It's my understanding starter fluid will achieve
. the same affect as your propane suggestion.
7. How do you suggest I clean the throttle
. body/valves? Yesterday opened the face of
. the throttle body and sprayed in some carb
. cleaner and worked the flappers with my
fingers.
. 8. I also sprayed carb cleaner around the
. linkages and components above the throttle
body.
Old 01-03-24, 12:46 PM
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Maybe you could do a smoke test to look for the large vacuum leak that @LongDuck is suggesting as the root cause?

For the AFM question, there must be a factory manual test for that...

So I googled "FB RX7 GSL-SE air flow meter test" and here in our lovely forum resides the following:

https://www.rx7club.com/1st-generati.../#&gid=1&pid=1

And post #3 seems directly on point.
Old 01-03-24, 01:48 PM
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Is thus the default / cold engine state of GSL-SE throttle valves?

Should they be at a 90 degree, as shown, or more up and down (closed)?

If I close them by hand they don't stay closed and they don't 'snap' back to 90, rather they slowly fall back to 90.

Thoughts?

Old 01-04-24, 11:05 AM
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Open is correct.
Old 01-04-24, 12:12 PM
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Ok sorry for not getting back to you quicker but here’s a few answers for your questions.
As far as starter fluid vs propane goes it’s a personal preference thing. I’m cheap and propane goes a lot farther than starter fluid. Also, there’s nothing to prove me right so take this for with a grain of salt, I personally feel that anything that can cause my hands to dry out and even causes the skin to split can’t be good on 40 year old vacuum tubes. Nothing I’ve read proves my point so it’s simply a personal preference.
For the throttle body just inspect both the primary and secondary air intake plates for carbon build up which could cause less air to get past the plates, especially the secondary plate during start up. As for the primary plates, they should be closed when the engine isn’t running or the gas peddle isn’t being pushed down, basically if they are perpendicular to the ground and no air is flowing by them, due to a little carbon build up they’re good to go. The secondary plate should be open slightly, how far open it will be is based off the temperature outside as well as the motor’s temperature, this is to allow the proper amount of air into the system while starting the engine. Once it starts and you give it some gas that’s when the 2 primary plates will begin to open, being a perfectionist I just added the part about the primary plates opening when the secondary plate turns about 15 degrees. If you sprayed it down with carburetor cleaner and the body looked good then all you need to do is spray all the moving parts with lithium grease and put it back together.
If I read the previous comments correctly and it’s now starting on its own and is idling at 3400 RPM’s, when cold, without needing anyone to push on the gas pedal, that’s a good sign. It’s been a long time since I had to mess with the EFI but the motor should idle at a higher RPM while it’s warming up. Once it’s warmed up, I used to take it on a short trip to ensure it’s warm and then check the idle. If it’s still idling high and you’re sure there’s no vacuum issues or air flowing in through a gasket. Basically everything that’s been suggested in your thread then it might be time to adjust your TPS, I made my own tester for this(I’m almost positive that there’s a how to guide to build one in the archives)I actually just leave it plugged into the TPS tester plug, and then if that’s all in spec then there’s always a chance the idle adjustment screw needs to be, well, adjusted.
Now I just want to say that there are plenty of amazing people on this forum who knows so much more about rotary motors than I which is exactly why I never post here but this post reminded me of when I saw my first rotary motor and fell in love with them. I just wanted to pass on my own experiences with the gsl-se but I think listening to another one of these guys or gals probably makes more sense.

After all my first encounter with a rotary motor had nothing to do with a car. Instead we had Atkins Rotaries building us motors, attaching superchargers to them and sending them to us in Alaska. We were installing them in our new smaller model Airboats. Rotaries were the perfect fit for the purpose when used alongside their superchargers. They were lightweight, solid power plant for the boats, only 9 or 10 moving parts in the motor which seemed like a much better option compared to boinger motors and then there was the power band all along the higher RPM’s. I was mind blowing to a kid who had only ever seen or worked on big block marine built Chevy crate motors that we used in our larger boats. That was back in the 1990’s and I loved that motor. Hell I didn’t own an actual RX-7 until I was much older and my boss gave one to me because she wanted her driveway back after her husband died. Honestly I thought she had given me a Datsun 240z until I got it home and opened up the hood and it all came flooding back. I live in Washington now and I actually visited Atkins Rotary’s way back when it was located on an airstrip, mainly for parts but I also wanted to meet the man who introduced me to Rotary Motors. His son runs it now but I was lucky enough to meet his father that day. Anyways TLDR.
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Old 01-04-24, 01:25 PM
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Thank you for the detailed response.

Secondary throttle plates are as you describe.

Never took the throttle body apart, just trying to see if I can make adjustments and clean it up before having to take it apart.

I'm still checking for vacuum leaks.

Took my air flow meter out and bench tested it. All seems to be well there.



Just lost my starter, so I'm replacing that now.
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