83 SC Died on me today....
 

Hi All,

My 83SC decided to die on me today.* 43K original miles, 7 years of my ownership with no problems ever.* It was her second time out this season (summer weekend car) afor an appearance in the town Memorial Day parade.* As soon as I dropped off my Veteran passenger and startied on my way home, she started to studder on a shift from first to 2nds.* 1/2 mile down the street she died at a stop sign with a loud backfire and some smoke.

I let her cool off for a few min and the restarted and made it two miles before the same stalling.**

I made it home after about 4 stalls with a few min to settle on the side of the road before restarting.**

A couple stalls concluded with a LOUD backfire.

If I would attempt a start immediately ater stall she would not fire.* After 5 min sitting idle she would fire, run rough, then settle into a normal idel....

It seems like a clear fuel problme to me.* Any thoughts on hoe to troublewhoot?

Thanks,

Bryan

Bryan,

I'd start with the dead simple stuff that can die suddenly. Under your passenger car seat there is a relay. If it's original it's silver. Those are known to drop out causing lean condition, not quite backfire lean, but a good start. Second is ignition, warm car, studder on shifts, could be the coil or the green distributor wire to the left of your fan. At least you can google how to check this stuff out..

Glad you got home.

Phil

Sorry to hear that Bryan. Fellow '83 SC owner here, a coup with ~ 163K miles. Certainly could be a fuel issue. I would suggest checking the spark as well.

Like you, I also don't drive my SC very often. Last year ( ~ 100 miles ago) I experienced similar to what you described in your post. T

The car died/stalled, but I was able to restart it and go another mile or so, then died again. Repeat 2 ~ 3 times before completely dead. I did not experience backfire or see any smoke though.

My local air-cooled tech diagnosed it to be a dead CDI box and replaced with new, and also replaced the ignition coil (both Perma Tune).

Following this post to see how it turns out for you. Good luck!

Keep a timing light with you and when it won’t start, check for spark. Perma-tune CDI boxes seem to heat fail and once cool will work again.

pop-off
 

Check your pop-off valve......

Agree with others on checking the simple stuff incl. the common fail of the DME first.
Since your location is unknown and this is a “seasonal” driver, I kind of doubt bad gas unless there hasn’t been a fill up in a couple years without any stabilizer additive and relying on old fuel for the first drive of the season.
That said, what is/was your gas gauge read? Anything at 1/4 tank could be an inaccurate reading - e.g. Out of gas. I had that experience.
As for a stale fuel delivery issue, it could be an easy issue to remedy using a fresh fill up with 93-94 premium gasoline along with a proper dosage of an injector cleaner then a long, long drive to clean out any foul fuel and free up any clogged injector.

Hi All,

Gas was filled first day out. 3/4 on the gauge.
Oil is good, temp was good, all was totally fine. My first day out she drove great other than being 42 years old and bone stock with some tired suspension.

I'll look into the above suggestions and get back tomorrow if time allows.

I havent tried to start her up since parking in the garage. I'll give that a go and see what happens.

Hi All,

Gas was filled first day out. 3/4 on the gauge.
Oil is good, temp was good, all was totally fine. My first day out she drove great other than being 42 years old and bone stock with some tired suspension.

I'll look into the above suggestions and get back tomorrow if time allows.

I havent tried to start her up since parking in the garage. I'll give that a go and see what happens.

Just tried her. No start.
What is the possibility of it being a fuel pump?
I'll check for spark tomorrow but it sounds to me like there is no fuel.

Seems vaguely similar to when my SC's CDI box went south. Do you hear the CDI whine/whistle with the ignition on?

Not always a good test! Just pull the coil wire & check for a spark while cranking.
Also, use carb/brake cleaner into the intake to check for a fuel problem.

Basic trouble-shooting is that simple!

1) check the pop off valve if you have one, failing that;
2) check and/or replace the DME relay, failing that
3) find a shop, or a friend who has a like CDI box and swap it out for a test drive.

It's an '83, so no DME relays to consider.

Where was the smoke coming from, the pipe, or the engine bay?

What do your plugs look like? Black and wet, or calcined white?

What is the nominal fuel pressure when running?

Initially I had a little smoke from the engine bay. After that all smoke was from the exhaust. Will run some basic troubleshooting today and report back.

its an SC , no DME . or DME relay ..

SCs are far more reliable for starting than there 3.2 brothers so this will be a failry simple process.

There is no DME, no DME relay, no Crank or reference sensors or head temp sensors.. it is a very simple reliable system.

If it is all stock it is very simple , complexity comes from changes people make that make it unreliable in my eyes.

if someone has added a pop off valve , check that , they break loose and the car will have trouble staying running if it breaks free due to unmetered air.
If someone has changed the system to permadoom, then that could be a suspect too as they are not as reliable as Bosch CDI and lots fail.
If it has the Brazilian bosch coil and not the original Black one that is also highly suspect as basically they are just junk.

If it is all stock , i would check cap and rotor first make sure cap is secure and rotor hasn't disintegrated underneath it. the timing light idea is a good one to see if you have spark pulse.. when cranking.
If no spark, it could be the green wire or the CDI unit itself which you can have repaired.

on the fuel side it could be the fuel pump , that is an easy test when lifting the air plate , but remember if you do this you are running fuel into your cylinders.

Good luck.

43,000 miles ... died with a loud bang? I'll go with the tried and true. Airbox explosion.

Terrible! More guessing in this thread.

start with the basics
Check your fuse for fuel pump no 6 towards the front if you have A/C If not no.3 If it plastic it is possible it is defective.,Use another and try to start.
Also.remove the straps on the air filter and take pictures of the air box so we can see it if it has a damaged..report with this

Fortunate, a no start is a lot easier to diagnose than intermittent. fuel/spark/air.