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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 07-18-16 11:00 PM

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?


GSLSEforme 07-19-16 08:08 AM

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?

andernamen 07-19-16 09:00 AM

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.

Stripgear 07-19-16 10:39 AM

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.

tallbozo 07-19-16 02:13 PM

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.


Originally Posted by GSLSEforme (Post 12087022)
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?


tallbozo 07-19-16 02:14 PM

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


Originally Posted by Stripgear (Post 12087063)
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.


FührerTüner 07-19-16 02:20 PM

Check compression

GSLSEforme 07-19-16 07:47 PM

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.....

LongDuck 07-19-16 08:27 PM

"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?

tallbozo 07-20-16 11:38 PM

3 Attachment(s)
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?


LongDuck 07-21-16 09:20 PM

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.

tallbozo 07-21-16 10:04 PM

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




Originally Posted by LongDuck (Post 12088015)
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.


tallbozo 07-22-16 09:24 AM

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

tallbozo 07-23-16 11:36 AM

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!

GSLSEforme 07-23-16 01:38 PM

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

tallbozo 07-23-16 02:02 PM

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

tallbozo 07-23-16 02:16 PM

https://youtu.be/I3thvjW1Pw4

tallbozo 07-23-16 02:17 PM

Yes the sensor passed ohm testing.


Originally Posted by GSLSEforme (Post 12088509)
Are you able to ohm that sensor and get any kind of reading?


tallbozo 07-23-16 03:56 PM

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

KansasCityREPU 07-23-16 05:11 PM

Have you checked compression?

tallbozo 07-23-16 06:03 PM

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.


Originally Posted by KansasCityREPU (Post 12088566)
Have you checked compression?


tallbozo 07-25-16 10:21 AM

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.

FührerTüner 07-25-16 11:52 AM

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

LongDuck 07-26-16 01:27 AM

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...

tallbozo 08-06-16 01:25 PM

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


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