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-   -   GSL-SE No Start (Possibly Timing?) - Video included (https://www.rx7club.com/1st-generation-specific-1979-1985-18/gsl-se-no-start-possibly-timing-video-included-1103065/)

tallbozo 08-06-16 01:26 PM


tallbozo 08-07-16 01:36 AM

Well I was out on a quick drive this evening and then did a 1/2 throttle pull in 3rd gear and then all of a sudden, no power. It being in gear kept the motor spinning but once we came to a stop it died. It turns over but sounds different than before like the starter makes a higher pitch sound like it has less resistance.

My guess is I lost compression. I'll check it in the morning and see what the compression numbers say...ehh....

LongDuck 08-07-16 01:39 AM

First off, those are the wrong plugs. You want Nippon Denso BR8EQ-14 for both leading and trailing, with BR7's if you can't get BR8's. Reason being that they have the correct electrode placement and number to run properly with the A/F ratios you can expect out of these simple EFI systems in the -SE.

If those are your Leading plugs, lower plugs from the engine, then the front looks about like I'd expect and the rear is showing signs of excessive oil burning - likely due to old and tired oil control rings allowing oil to get past on the vacuum side and drawn into the intake charge.

Its not indicative of fuel injection problems to my eyes, but could be the front injector isn't flowing properly resulting in an overly lean mixture, hence looking cleaner. Without knowing how long those plugs have been in there, and that they're not the factory plugs makes it hard to guess.

tallbozo 08-07-16 01:48 AM


Originally Posted by LongDuck (Post 12093432)
First off, those are the wrong plugs. You want Nippon Denso BR8EQ-14 for both leading and trailing, with BR7's if you can't get BR8's. Reason being that they have the correct electrode placement and number to run properly with the A/F ratios you can expect out of these simple EFI systems in the -SE.

If those are your Leading plugs, lower plugs from the engine, then the front looks about like I'd expect and the rear is showing signs of excessive oil burning - likely due to old and tired oil control rings allowing oil to get past on the vacuum side and drawn into the intake charge.

Its not indicative of fuel injection problems to my eyes, but could be the front injector isn't flowing properly resulting in an overly lean mixture, hence looking cleaner. Without knowing how long those plugs have been in there, and that they're not the factory plugs makes it hard to guess.

Those were brand new plugs so maybe 100 miles on them. Oil control seals were brand new OEM.

It burned super clean out the tail pipe with no smell of oil burning so the build up on the plugs was a bit concerning.

Now with it not running, I am wondering if I was only getting fuel to one rotor and that one lost compression (now no power at all)

wankel=awesome 08-07-16 09:33 AM

You know if you don't hold open the schrader valve on that tester, youre getting an invalid reading. That first pulse looked extremely low, and I'd be willing to bet that all 3 faces are low with the valve open.

Jeff20B 08-07-16 11:11 AM

1) lowish compression from a fresh rebuild. Give it a few hundred miles.
2) wrong plugs like wankel=awesome said. Get NGK BR8EQ-14
3) Ditch the EFI and... well, you know where I'm going with that lol.

tallbozo 08-07-16 12:21 PM


Just did a compression check this morning and as i suspected, no compression on the front rotor. Looks like its time to pull the engine. I pulled both bottom plugs and the rear rotor sounds good but the front has ZERO compression. Grrr.....

LongDuck 08-07-16 05:09 PM

Before you pull the engine, squirt some Marve Mystery Oil, or plain engine oil, into the spark plug holes on that rotor and give it a whirl to distribute the oil amongst the seals, the try to start it up again. If you have a leaky injector on the front rotor, it will wash away the oil and kill compression on all sides. One bad apex seal shows as only ONE pulse on a pressure test, as it kills 2 rotor faces for compression.

Try that first, and retest compression, as its a lot easier than pulling the engine and could diagnose a problem with fuel draindown on that front injector, which may also explain an overly clean front set of plugs. Still recommending you get the right plugs, by the way. Hope for the best,

tallbozo 08-07-16 07:41 PM


Originally Posted by LongDuck (Post 12093604)
Before you pull the engine, squirt some Marve Mystery Oil, or plain engine oil, into the spark plug holes on that rotor and give it a whirl to distribute the oil amongst the seals, the try to start it up again. If you have a leaky injector on the front rotor, it will wash away the oil and kill compression on all sides. One bad apex seal shows as only ONE pulse on a pressure test, as it kills 2 rotor faces for compression.

Try that first, and retest compression, as its a lot easier than pulling the engine and could diagnose a problem with fuel draindown on that front injector, which may also explain an overly clean front set of plugs. Still recommending you get the right plugs, by the way. Hope for the best,

Awesome there's still hope! I will get new plugs and try to lube the front rotor up. Thanks for the suggestions

Jeff20B 08-08-16 01:17 AM

It could be your tight side seals binding up. Just a possibility.

LongDuck 08-08-16 01:25 AM

^^^Jeff - you're saying that his seals may not have popped out against the housings to allow compression?

Jeff20B 08-08-16 05:29 PM

Being brand new seals, and not being sure how clean of carb his slots are, it is a possibility.

I once built an engine with side seals that were too long and tight. I was following advice I read somewhere on one of these forums. Bad advice. I don't think tallbozo did that here though.

Side seals are fragile. They don't tolerate any bending. Maybe one or more got a little out of true and are binding now after some mileage and carbon built up on them. That happened to one of my engines once. A quickie teardown and a simple swap to one healthy good side seal is what it took. The fresh rebuild fired right up and idled perfectly... on both rotors! :)

FührerTüner 08-09-16 09:21 AM

didnt i say check compression like 3 weeks ago?

tallbozo 03-21-17 06:30 PM

Ok time to get back into this thing! I have new plugs and have been soaking the front rotor in oil and will be hoping to get compression back on the front rotor.

Any suggestions on if I should hand crank or pull the fuel pump fuse and let the starter spin in this scenario?

GSLSEforme 03-21-17 07:27 PM

Turn the engine over by hand several revolutions to distribute the oil. How much oil have you put into the rotor housing to "soak" the rotor. Last post 8-7-16,has engine been sitting all this time?

tallbozo 03-21-17 08:11 PM


Originally Posted by GSLSEforme (Post 12165186)
Turn the engine over by hand several revolutions to distribute the oil. How much oil have you put into the rotor housing to "soak" the rotor. Last post 8-7-16,has engine been sitting all this time?

I added the oil 3 months ago and hand cranked it. I added enough for it to dribble out. It's been sitting since. I just got some MMO and might add that in after hand cranking it tomorrow.

GSLSEforme 03-21-17 08:25 PM

Stick with the plain oil since that's what is already in there. Use cap from bottle oil came in and put it about two capfuls and turn the engine over several times. Put plugs in and start it and see what you get. Make sure neighbors know you're working on your car and don't call fire dept. from all the smoke...

tallbozo 03-21-17 08:39 PM


Originally Posted by GSLSEforme (Post 12165208)
Stick with the plain oil since that's what is already in there. Use cap from bottle oil came in and put it about two capfuls and turn the engine over several times. Put plugs in and start it and see what you get. Make sure neighbors know you're working on your car and don't call fire dept. from all the smoke...

Ha yep! I'll be ready for smoke. I am hoping to get compression back but am preparing to pull the motor. I think I was only running on one rotor the whole time.

Any tips on the compression check? I hear you have to hold the valve open and see how it spikes on each face correct?

LongDuck 03-22-17 01:27 AM

Man, that was a lot of re-reading to get back up to speed. Did you take a close look at your wiring harness to be sure everything is hooked up tightly (fuel injector plugs)?

As above, I'd add some more oil, spin it over a few times, and then try to start it.

GSLSEforme 03-22-17 05:55 AM

Just start the engine and keep it running til it clears up,may take several minutes. If at all possible,compression test should be done on the engine when warmed to operating temp. Having experienced the way engine ran before,you'll know within a few minutes if it's better/same. If you have no frame of reference(don't know if engine has ever run since you've owned it) the engine should idle butter smooth,respond to throttle smoothly/quickly. Hoping for the best for you.

tallbozo 03-22-17 09:28 AM

To give some background, I rebuilt the motor last summer. I bought the car with a seized motor which I disassembled and cleaned and rebuilt with a Mazda rebuild kit.

I got the car running but it felt underpowered which I thought was a timing, fuel delivery, spark plug issue, but I never got to do a compression check before I lost compression on the front rotor. I fear I didn't have good compression on one rotor and was limping along till the front rotor went.

I thought I had issues with fuel delivery due to having original injectors and having the wrong plugs. I have ordered both the correct plugs and new injectors to hopefully eliminate that as the cause.

If I can't get it to run this weekend, I'll do a compression check and then start the process to pull the motor. Thanks for the help and suggestions. I truly value this forum and the wisdom it's users have.

tallbozo 03-24-17 03:32 PM

Still zero compression in the front rotor. Time for rebuild #2.

GSLSEforme 03-24-17 03:46 PM

Well that sucks...


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