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How to drain gas tank

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Old 10-09-17, 01:15 PM
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Originally Posted by RXrick View Post
Ok, see attached photos. This spade connector is always connected when I try to start the car. Is there a way to measure the signal at the blade connection with a VOM? Is so, what is the procedure? Detach the connector then attach the + of the VOM to the terminal and the - of the VOM to ground and crank the engine, then note the voltage?
There will be 12 volts at that terminal with the key on,the igniter on the distributor switches the voltage to fire the coil when the signal generator(pick up coil) that's attached to it sends a voltage waveform to trigger it. You may be able to see this with a test light connected at cranking speed that will flash off/on or blink each time the igniter switches. Don't think the voltmeter would be fast enough to register accurately what is happening. The spark test you're going to do will tell you if all this is operational,have person cranking the car over watch for tach needle to wiggle while cranking,if it is the ECU should be getting same info.
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Old 10-09-17, 01:25 PM
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One more thing,actually two...1st voltmeter gauge is not terribly accurate as a mass produced unit+wiring in car is 30 plus years old,coupled with the fact the starter motor which is a fantastic power consumer along with fuel pump,ecu,injectors,igniters and coils are simultaneously pulling their alloted amounts of voltage/current from the battery. If you were to connect your multimeter to the battery during cranking,you would see something like 10+ volts. Regarding oil pressure gauge registering 1/4 gauge travel while cranking,that's consistent with good oil pressure with a running engine.
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Old 10-09-17, 02:03 PM
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Originally Posted by LongDuck View Post
You're missing the Black Wire EFI Signal lead on the front (Trailing) coil. The one that's on there now goes to the ignitor. There's a separate black wire with a spade connector that feeds your ECU with the EFI signal, and if it's not connected to the Trailing Coil, you're not getting the injectors to fire. It really could be that simple.

A trick for advanced troubleshooting is that the engine will run (poorly) if you connect the EFI Signal lead to the LEADING coil - which is the incorrect coil, but will let the ECU determine when to fire the ignitors, however off time. This will limp you home if your Trailing Coil or Trailing Ignitor fails for some reason.

Find that black wire with spade connector and plug it onto the opposite side blade on the same ignitor lead. This will restore your EFI signal and should get it up and running.

Also, take a picture showing which wires are connected to both coils and I can tell you more about what's going on.
There is a black wire attached to that connector you just cannot see it in the photo. (There are two wires attached to that blade connector.)

i will ill take more photos and post them tonight. Thank you!
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Old 10-09-17, 03:45 PM
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Originally Posted by GSLSEforme View Post
Do the spark test as i outlined in previous post,this will tell you if BOTH Leading and trailing ignition are operational,if either isn't we'll focus on why that is so. Completely functional ignition system is one of three things needed,the other two are fuel,in the right quantity and proper compression.
Can I pull all the plugs out and line them up on the manifold cover, crank the engine and test them all at the same time? (Maybe I can record the test with my phone and post the video for you to see.)
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Old 10-09-17, 04:19 PM
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Originally Posted by RXrick View Post
Can I pull all the plugs out and line them up on the manifold cover, crank the engine and test them all at the same time? (Maybe I can record the test with my phone and post the video for you to see.)
Yes,pull them all and ground them on top of the engine and watch and compare all- all should be same color and intensity. Have someone else crank the car so you can watch plugs firing closeup. Video and post results if you like, have person cranking car watch tach needle for wiggles.
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Old 10-09-17, 08:38 PM
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Originally Posted by LongDuck View Post
You're missing the Black Wire EFI Signal lead on the front (Trailing) coil. The one that's on there now goes to the ignitor. There's a separate black wire with a spade connector that feeds your ECU with the EFI signal, and if it's not connected to the Trailing Coil, you're not getting the injectors to fire. It really could be that simple.

Find that black wire with spade connector and plug it onto the opposite side blade on the same ignitor lead. This will restore your EFI signal and should get it up and running.

Also, take a picture showing which wires are connected to both coils and I can tell you more about what's going on.
Ok, here are the pics of my coils...
Attached Thumbnails
How to drain gas tank-coils_org.jpg   How to drain gas tank-trail-lead-coil_org.jpg   How to drain gas tank-trailing-coil_1.jpg   How to drain gas tank-leading-coil_1.jpg  
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Old 10-09-17, 08:44 PM
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On a side note, I know the green connector is to jump start (via jumper wire) the fuel pump, but what is the other connector for? It does not connect to anything. (These are by the air filter).
Attached Thumbnails
How to drain gas tank-connectors-air-filter_1.jpg   How to drain gas tank-connectors-air_ecu_3.jpg   How to drain gas tank-connectors-air_ecu_2.jpg  

Last edited by RXrick; 10-09-17 at 08:49 PM. Reason: dupe image
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Old 10-10-17, 09:16 PM
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Originally Posted by GSLSEforme View Post
Yes,pull them all and ground them on top of the engine and watch and compare all- all should be same color and intensity. Have someone else crank the car so you can watch plugs firing closeup. Video and post results if you like, have person cranking car watch tach needle for wiggles.
Is this what we had in mind? (see photos) Unfortunately I needed to charge the battery to get a good test result, and my helper was unavailable to crank the engine for me tonight, so the test and video will need to wait until tomorrow.
Attached Thumbnails
How to drain gas tank-plugs_manifold-1.jpg   How to drain gas tank-plugs_manifold-2.jpg  
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Old 10-10-17, 09:21 PM
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Your coil wiring looks correct. Be sure to push the rubber covers on top of your positive leads to protect them from shorts, though. How did the removal and test of spark plugs go?

Also, on the connectors by the air flow meter, the green 3-lead is for setting Throttle Position Sensor using a "TPS 2 Bulb Fixture". The 2-lead with the black rubber cover is to test the fuel pump without the engine running. When shunted across the 2-leads, it replicates the air sensor switch in the air flow meter showing incoming air. Our cars were designed NOT to engage fuel pump operation unless air is coming into the engine to prevent flooding.

Also, your RE-EGI intake box is aluminum and not a good conductor. Find something steel to ground the plugs during your spark test. Hoping for the best,

Last edited by LongDuck; 10-10-17 at 09:23 PM.
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Old 10-10-17, 10:48 PM
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Originally Posted by LongDuck View Post
Your coil wiring looks correct. Be sure to push the rubber covers on top of your positive leads to protect them from shorts, though. How did the removal and test of spark plugs go?

Also, on the connectors by the air flow meter, the green 3-lead is for setting Throttle Position Sensor using a "TPS 2 Bulb Fixture". The 2-lead with the black rubber cover is to test the fuel pump without the engine running. When shunted across the 2-leads, it replicates the air sensor switch in the air flow meter showing incoming air. Our cars were designed NOT to engage fuel pump operation unless air is coming into the engine to prevent flooding.

Also, your RE-EGI intake box is aluminum and not a good conductor. Find something steel to ground the plugs during your spark test. Hoping for the best,
Would this fireplace log thing (see photo) work better than the RE-EFI aluminum intake box?

I was unable to do any spark test tonight. Hopefully, with your blessings with this fireplace thing, I will do the spark plug test tomorrow evening. And thanks for the explanation of the connectors by the air flow filter. This was probably explained to me before but I had forgotten...

My plan is to record a video of the spark test on all the plugs tomorrow evening and post here tomorrow night, pending if you think my fireplace log thingy would be a good ground. Otherwise, I might have to look for another steel thing for the test (and I really want to test all the plugs together at the same time because I think it would make a great recording to see ALL the plugs firing at the same time and what that might look like :-) Thanks for your help, LongDuck!
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Old 10-11-17, 06:35 AM
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Don't wish to discount LongDuck's advice regarding using intake plenum as a ground. Consider this...the rotor housings the spark plugs are installed in are aluminum...the dynamic chamber is thru bolted to the intake manifold which is bolted to rotor housing=no better path to ground. I have done this quick test this way for many years for this reason and one other. By placing plugs up top on dynamic chamber,they are far enough away from spark plug holes and any fuel mist that might be expelled from them during test cranking that there's no possible chance of ignition of that mist-should there be any. This test should be performed quickly-just long enough to verify quality of spark at all plugs. If you're doing this test and wish to video,be quick about it. The closer you are to the plugs,the better you will see spark. The fireplace log,while good ground material would need to be grounded to the car and frankly would be a cumbersome operation.IMHO.
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Old 10-11-17, 09:28 PM
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^^^This guy's done it on top of the dynamic intake chamber, so I'd trust his opinion.

(I hope you were kidding about your fireplace log device,...) I tend to ground stuff to the brackets for the A/C or Alternator, as I know those are grounded theough the engine straps, but I've also run extra grounds to the engine because you cant have too many! Good luck, and post spark results,
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Old 10-11-17, 09:50 PM
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Originally Posted by LongDuck View Post
^^^This guy's done it on top of the dynamic intake chamber, so I'd trust his opinion.

(I hope you were kidding about your fireplace log device,...) I tend to ground stuff to the brackets for the A/C or Alternator, as I know those are grounded theough the engine straps, but I've also run extra grounds to the engine because you cant have too many! Good luck, and post spark results,
I recorded the test (with my iPhone) but the file is huge and there is a 5MB limit here. I imported the file into Adobe Premier and I'm trying to re-size and down-size the file to 5MB. Not sure of the quality at that point but I'll see what I can do. This may take a while.

Essentially, I'm not sure what I'm suppose to see. The tach wiggles, but the spark at the electrodes fire at different times, and I'm not sure they spark at ALL four electrodes. What if I only see spark at 2-3 electrodes? Hope you guys can see this test. Stay tuned. Oh, and I wasn't kidding about the fireplace log thingy :-P
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Old 10-11-17, 10:07 PM
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This is why you're doing this test. They all do need to fire-consistently for car to start and run. I ll watch for your video. A thought,because of engine motion while cranking you may want to put a piece of wood maybe 10" section of 2x3 or 4 with something of some weight on top of plugs/wires while you retest? to verify all plugs stay securely in contact with engine housing during cranking/testing. Only really important that you see spark consistently at one of the four electrodes on EACH plug. The idea behind the 4 electrodes is this,when installed in running engine making power under way,plugs see a lot of heat. Unlike a piston engine that fires each plug every 4 cycles of crankshaft rotation,a rotary fires each plug 3x in one rotation of e shaft. 3x for leading and same for trailing. The plugs don't get a break,neither does the whole ignition system. On the plugs in your rotary,each time they fire,the next ignition event will fire the plug from another of the 4 side electrodes and that will be from whichever of them is coolest. Hope makes sense.
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Old 10-11-17, 10:25 PM
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Originally Posted by GSLSEforme View Post
Yes,pull them all and ground them on top of the engine and watch and compare all- all should be same color and intensity. Have someone else crank the car so you can watch plugs firing closeup. Video and post results if you like, have person cranking car watch tach needle for wiggles.
Here is the recording. It's under 5MB per the forum requirements. Sorry it can't be larger, but I am limited to less than 5MB. Hopefully you will be able to get a good view of what is happening with the spark issue. I have no idea if this is good news or bad, but my wife told me my tach wiggles :-)

Just realized my file is MP4, and I'm not sure if this is compatible with this forum............... Guess we'll find out.
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Old 10-11-17, 11:34 PM
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Originally Posted by GSLSEforme View Post
This is why you're doing this test. They all do need to fire-consistently for car to start and run. I ll watch for your video. A thought,because of engine motion while cranking you may want to put a piece of wood maybe 10" section of 2x3 or 4 with something of some weight on top of plugs/wires while you retest? to verify all plugs stay securely in contact with engine housing during cranking/testing. Only really important that you see spark consistently at one of the four electrodes on EACH plug. The idea behind the 4 electrodes is this,when installed in running engine making power under way,plugs see a lot of heat. Unlike a piston engine that fires each plug every 4 cycles of crankshaft rotation,a rotary fires each plug 3x in one rotation of e shaft. 3x for leading and same for trailing. The plugs don't get a break,neither does the whole ignition system. On the plugs in your rotary,each time they fire,the next ignition event will fire the plug from another of the 4 side electrodes and that will be from whichever of them is coolest. Hope makes sense.
Yes, this all makes sense. I never knew any of this before. Thank you for the detailed explanation. You and LongDuck have educated me greatly, and I am very appreciative. My wife asks me why I just don't take the car to a shop, and I tell her because I belong to this RX7 Club forum and the people here are amazingly knowledgeable about my car, more than all the mechanics at the shop that I would take the car to.

I have rendered out a few different video formats (under 5MB) that I can now upload. I'm just trying to render out the best one for you to view now. It will happen tonight. Thanks!!
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Old 10-12-17, 12:51 AM
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GSLSE spark plug test

Okay guys, here is the video recording of my spark plug test. I laid all the plugs on top of the RE-EFI cover and placed a red brick on top of the plugs to make sure they made contact with the (aluminum) surface. The video file is .wmv file. I have an FLV file which is better but this forum will not accept FLV files...

Anyway, hope this vid helps solve the mystery, or at least pinpoint or eliminate spark as a possible culprit :-)
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Old 10-12-17, 06:52 AM
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Just looked at your video,spark looks ok. You can rule that out as a cause for no start. FYI your crank sequence is about 10x longer than necessary. Need to give starter a rest when trying to start car after 20 seconds or so of cranking,gets hot quickly. Take note of how warm your battery cables get after one of your extended cranking periods. Can you take a video of your next start attempt so we can listen to it turning over. Suggest you put about 20 cc of engine oil in both leading plug holes and turn engine thru by hand about1/2 dozen times to distribute around rotor housing. Charge the battery to be 100%,don't overcharge it.
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Old 10-12-17, 08:34 AM
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Originally Posted by GSLSEforme View Post
Just looked at your video,spark looks ok. You can rule that out as a cause for no start. FYI your crank sequence is about 10x longer than necessary. Need to give starter a rest when trying to start car after 20 seconds or so of cranking,gets hot quickly. Take note of how warm your battery cables get after one of your extended cranking periods. Can you take a video of your next start attempt so we can listen to it turning over. Suggest you put about 20 cc of engine oil in both leading plug holes and turn engine thru by hand about1/2 dozen times to distribute around rotor housing. Charge the battery to be 100%,don't overcharge it.
Do you mean turn the fan about 6x or turn the engine all the over 6x (via turning the fan)? Just bought a new battery one week ago. I will charge it before the next start attempt.
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Old 10-12-17, 08:35 AM
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Have you tried to pull start it yet? It works really well. The battery can turn the engine at about 250 RPM but pull starting can get 2000+ RPM when started in second gear.
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Old 10-12-17, 09:35 AM
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Originally Posted by KansasCityREPU View Post
Have you tried to pull start it yet? It works really well. The battery can turn the engine at about 250 RPM but pull starting can get 2000+ RPM when started in second gear.
No. I don't have the means to pull start. So do I turn the engine over 6x or just turn the fan 6x?
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Old 10-12-17, 12:38 PM
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Originally Posted by LongDuck View Post
^^^This guy's done it on top of the dynamic intake chamber, so I'd trust his opinion.

....Good luck, and post spark results,
Now that we know I have spark and so that can be ruled out as my problem, it looks like now I need to look at "compression" and "fuel" (what about "air" ? )

i do do not have any equipment to test compression or fuel pressure, etc. Is there a cheap fast down and dirty way to check these things? Or should I take my car to a shop at this point?
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Old 10-12-17, 02:06 PM
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Originally Posted by RXrick View Post
Now that we know I have spark and so that can be ruled out as my problem, it looks like now I need to look at "compression" and "fuel" (what about "air" ? )

i do do not have any equipment to test compression or fuel pressure, etc. Is there a cheap fast down and dirty way to check these things? Or should I take my car to a shop at this point?
Use a turkey Bastet and inject about 20 cc of engine oil into each leading plug hole. Turning fan is...turning fan against fan clutch which does not turn engine over. Easiest way is to grab a/c compressor drive belt and pull toward you. This belt is connected directly to e shaft=crankshaft in piston engine. Pulling on belt will turn engine over,reach down as far as you can on top run of belt and pull,you'll get about 6" of belt in one pull. Do this about 20x,that will give you about 6 revolutions of the engine. Will caution you to not pinch your hand between belt and a/c pulley.
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Old 10-12-17, 02:09 PM
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Originally Posted by GSLSEforme View Post
Use a turkey Bastet and inject about 20 cc of engine oil into each leading plug hole. Turning fan is...turning fan against fan clutch which does not turn engine over. Easiest way is to grab a/c compressor drive belt and pull toward you. This belt is connected directly to e shaft=crankshaft in piston engine. Pulling on belt will turn engine over,reach down as far as you can on top run of belt and pull,you'll get about 6" of belt in one pull. Do this about 20x,that will give you about 6 revolutions of the engine. Will caution you to not pinch your hand between belt and a/c pulley.
That's turkey baster- phone trying to correct me.
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Old 10-12-17, 02:23 PM
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Originally Posted by RXrick View Post
Now that we know I have spark and so that can be ruled out as my problem, it looks like now I need to look at "compression" and "fuel" (what about "air" ? )

i do do not have any equipment to test compression or fuel pressure, etc. Is there a cheap fast down and dirty way to check these things? Or should I take my car to a shop at this point?
You can rent a compression gauge from some auto parts places that do so. Auto Zone,Advance Auto to name a few. There is a specific compression checking tool for use on rotary engines usually only found at Mazda dealership or shops that do a lot of rotary work. They're not cheap,I paid about $400 for mine some time ago. The type you can rent from a parts house will be for piston engines and while not ideal will give you a good idea of compression in your engine so you can rule this out as a cause for no start,sort of a pass/fail test. For what it's worth,you would be paying a shop to do what you're doing and they may not know as much as you about your car as you have this site as a resource. If you have the time and patience you should be able to get your car running on your own+ learn a lot more about your car than you ever wanted to know,lol. After going thru the process of fixing your car,you may feel more connected to it.
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