GSL-SE No Start (Possibly Timing?) - Video included
 

Hello,

I am working on getting a fresh rebuild started. Along with the rebuild, I have replaced:
- Starter
- Battery
- Spark Plugs

I can get it to almost fire using starter fluid, but then once that dies out, it struggles. I put fresh gas in and checked the spark plugs for flooding (No issues there).

The only thing I could think of is needing a new cap and rotor and check the timing. Does anyone have any good resources for setting the timing?

Can you hear the fuel pump run,do you have spark from leading and trailing plugs for certain? Sounds as if your battery is low,cranking speed falling off. Have not followed your build thread,did it run before you took it apart,how well,what was reason for rebuild?

If it was running before, I bet something was not connected properly. Check your igniters, distributor connections, etc. After this, check for spark. If you have a good spark, do the fuel pressure and volume test. Lastly, confirm TDC by removing the inspection plate on the passenger side. If all is in order, perform the unflood procedure. Keep working with it, you'll get it.

Check for spark and fuel pressure as others have said. I had the same problem. It turned out to be corrosion in the fuel injector electrical connector. Got new ones from NAPA and it started right up.

It was rebuilt due to carbon build up. It was running prior to the carbon lock.

I have it hooked up to a charger while cranking. The video was towards the end of the evening so the battery was getting tired.

I know the fuel pump is sending fuel because the plugs were soaked with gas after cranking it over a few times.

I will be replacing the cap and rotor and then attempting to work on timing once that is replaced.

Thanks I'll check that out as well. I know sometimes the not so obvious can be what prevents stuff from running.

Check compression

Are the plugs new or same that were in engine before you rebuilt it,if not new put fresh ones in. In your first post you said plugs were dry,recent post you say soaked with gas-that's flooded.... Have you done the de-flood procedure? If you've been cranking on it for a while,certain you have since you make mention of a battery charger, i would put a small amount of MMO or something similar,no atf,into plug holes and turn engine around several revolutions by hand to distribute the oil around rotor faces and seals. Any lubrication you may have had on these parts likely washed off with all that fuel. Take a page from the KISS philosophy here and recheck and verify the basics so you don't start chasing your tail. IF you have spark at all 4 plugs,pretty safe bet a set of fresh/dry plugs and fully charged battery it'll start right up. Have just seen too many times a set of plugs old or new washed down with gas will not start a car,it will try to start just like yours sounds in the video til more injected fuel washes them down again. De-flood,fully charged battery,fresh plugs.....

"You ain't got no tach signal, Lieutenant Dan!"

For the SE guys that means you don't have a trigger signal to your fuel injectors to fire, which is driven off of the Trailing Coil - same signal which drives the tachometer on the dash. Noticed in your video that the tach needle is only bouncing due to vibration from the engine spinning, as it should show RPM of the starter cranking it.

Several things; you said the plugs are wet, so its leaking fuel, likely enough to at least sputter with. But without a tach signal, more than likely your ignition system isn't working - notably the Trailing Coil. Try swapping your ignitors and see if you get Tach. Could also be that you have 2 bad ignitors and hence no spark at all. It's odd that you have fuel, but no tach...

Doublecheck your connections from the distributor to the coils, from the coils to the ignitors, and from the ignitors to the harness. It's in there somewhere and it will take a bit of troubleshooting to find it.

You put the rotor back when you put the distributor cap on, right?

I got it running! Its not at full power, but it starts easy and idles without smoking. Good oil pressure and no leaks.

It feels sluggish on the quick drive around the block. I am wondering if bad gas is the culprit? I also noticed this plug was missing off of the dynamic chamber (I think that is what it's called)?

I also have some bad exhaust leaks which (both rusted out and gasket leaks). Might just have to upgrade to a full RB setup? :)

Anyways, any suggestions from the video with the rough idle and bad throttle response? Timing still off?

Thats the second intake air temp sensor and is the cause for your rough running condition.

The intake air temp sensor in the Dynamic Chamber is used as a reference point berween there and the primary intake air temp sensor in the Air Flow Meter and helps the ECU to know air density and thus how much fuel should be added during injector pulse duration and injector timing. Without the reference point and differential between the two, the ECU has to guess at fuel map, which is why your engine isn't running well beyond an idle.

Finding a replacement may be difficult, but soldering on the pigtail may not be an option where it broke off. The sensors tend to seize in place making removal difficult, making this job a little harder than it ought to be. At any rate, thats your path to a fix.

Well I think I got lucky and it came out really easy. Time to try and solder this plug back on!

https://cimg4.ibsrv.net/gimg/www.rx7...8cc45fe22b.jpg

Whew friend saved the day! He had to chip off some of the plastic to get a more solid piece to solder to. I didn't have a chance to install it but I'll Saturday AM. Thanks for the help and I'll post updates once resolved.

Thanks


https://cimg2.ibsrv.net/gimg/www.rx7...3ce96cc21e.jpg

https://cimg4.ibsrv.net/gimg/www.rx7...efd91b898f.jpg

https://cimg6.ibsrv.net/gimg/www.rx7...e4bd988fd4.jpg

Well the plug is in but no dice. It starts if I squirt starter fluid in the intake but will not idle. I am replacing the fuel pump since I don't have a way to measure the pressure. I also have some injectors on standby in case it's still an issue.

I'll be working on this today so any other ideas would be helpful. Thanks!

Are you able to ohm that sensor and get any kind of reading?

New pump installed and cleaned off the plugs and it started. Still feels really down on power. Bad gas or injectors?

https://youtu.be/I3thvjW1Pw4

Yes the sensor passed ohm testing.

Well I got it running enough to go for a quick drive. It idles but it sounds like it is struggling. On the road it is sluggish like only half throttle max. Even when flooring it, it doesnt bog down but never really makes much power.

I put new gas in it and fuel injector cleaner and drove about 15 miles and it was fine putting around but just really slow. Got up to 60mph on a quick highway run but was not happy to be in 5th gear.

Timing? I'm at a loss now

Have you checked compression?

I will shortly. My neighbor has a compression tester so we will give that a check. It makes 3 solid swooshes on each rotor but I'll see what the PSI comes back at.

It idles a little smoother as the day has gone on(timing adjustments) just no power still.

We also found a couple vacuum leaks (main line from air pump to cat had a big hole). Going to trace down all the other lines and confirm no other leaks.

I haven't had a chance to test the compression but should be able to this week. I also had a suggestion that my cats could be plugged?

I also found a cracked hose (main hose from the air pump to the cat). I'll track down these leaks and see if that helps too.

I've been driving around and the sense of power is the same regardless of throttle application. 1/4 or full throttle feel exactly the same. Starts right up and idles ok around 800 but is a little shaky.

I dont think anyone should waste any more time until you check compression. Pretty sure youre only running on 1 rotor.

Sounds like it: search on my name and "running on one rotor" for my symptoms and a $7 injector pigtail fix. Given that your intake air temp sensor wiring was broken, could also be a broken connection on the injector harness if the PO liked to yank on wiring...

Just did a compression check and made 110 and 115psi.

https://cimg4.ibsrv.net/gimg/www.rx7...048cdcf49a.jpg

I also replaced the exhaust with a full RB system and feel minimal gains so the exhaust was not the culprit (but I did get to replace the exhaust anyways 😁)

So I'm thinking it's injector related. I have ordered some new ones and will also inspect the connectors.

I also noticed when doing the compression check how the plugs had different burn markings. Front rotor seemed cleaner while the rear had darker. This a clue to anyone?

https://cimg1.ibsrv.net/gimg/www.rx7...acf5f0a7a7.jpg

https://cimg3.ibsrv.net/gimg/www.rx7...bee5e3f151.jpg

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....

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)

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.

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.

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.....

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

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

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

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! :)

didnt i say check compression like 3 weeks ago?

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?

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.

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?

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.

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.

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.

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

Well that sucks...