Trouble Shooting tips needed NO SPARK (Page 1/1)
str8maxn APR 18, 07:53 PM
Hello everyone,


My car has been sitting all winter. I did start the car and went around the block about a month ago. Today, I went to start my LT1 Swapped Fiero and it would not turn on. I have fuel pressure but I don't think I have spark. To confirm, I took a spark plug wire off the front cycler, a screw driver and wire with alligator clips to find spark. I had no one to help out so, I filmed it on my phone. I jammed the screw drive into the spark plug wire, clip one end of the wire to it and ran the other end near the shock tower to film the spark. Cranked the engine over a few time and reviewed the video ... NO SPARK.


I am not sure how to go about trouble shooting.

What fuses or reply so I check?
Any advice would be greatly appreciated
Patrick APR 18, 08:13 PM

quote
Originally posted by str8maxn:

I jammed the screw drive into the spark plug wire, clip one end of the wire to it and ran the other end near the shock tower to film the spark. Cranked the engine over a few time and reviewed the video ... NO SPARK.



How "near"? A healthy spark should have no problem snapping across a 1/4" gap to ground. Perhaps try using the engine block/head as ground instead of the shock tower.
str8maxn APR 18, 08:28 PM

quote
Originally posted by Patrick:

How "near"? A healthy spark should have no problem snapping across a 1/4" gap to ground. Perhaps try using the engine block/head as ground instead of the shock tower.




I just realized I have a spark plug gap tool.. I have to try again tomorrow.


But assuming NO SPARK... where do I begin?
theogre APR 18, 09:04 PM
⚠️ Warning: Can "fry" coil(s) & more if spark tests are done wrong.

Video for spark is often not a good test because how most digi cam's work.
IOW maybe have spark but camera can't see for many reasons. go watch https://www.youtube.com/@TarylFixesAll etc to see many times they see spark but camera shows nothing.

Get a tester that replaces a plug or inline w/ a plug. If can't/won't get a helper to see, also Buy a "remote starter switch" so you can see & bump the starter too. That goes to Battery + & solenoid.

HEI or DIS ICM doesn't have a fuse. HEI Coil may or not have a fuse link buried in wire harness & depending how the swap is wired may still have this.

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)


The Ogre's Fiero Cave

jelly2m8 APR 18, 09:23 PM
Being an LT1 check for spark off of the ignition coil. If it's a stock LT1 ignition system that is a standard GM HEI coil pretty much the same you will find on a 2.8L. If you have spark there, you likely have an issue with the Optispark distributer, those are a known failure point. They are not fun to work at, very susceptible to moisture, especially if one has a failing water pump.

There is a plethora of information about Optispark diagnoses online, it makes 2.8L ignition module look bullet proof.
str8maxn APR 19, 11:51 AM

quote
Originally posted by jelly2m8:

Being an LT1 check for spark off of the ignition coil. If it's a stock LT1 ignition system that is a standard GM HEI coil pretty much the same you will find on a 2.8L. If you have spark there, you likely have an issue with the Optispark distributer, those are a known failure point. They are not fun to work at, very susceptible to moisture, especially if one has a failing water pump.

There is a plethora of information about Optispark diagnoses online, it makes 2.8L ignition module look bullet proof.




I hope it's not the optispark. I had it rebuilt MSD bullet Optispark by MSD, when I got the car. It has less than 1000 miles on it. I'll keep you posted as time permits.

Thank you
jelly2m8 APR 19, 01:31 PM
Ya check the coil first, that's pretty easy testing, if no spark, does it have power to it, how does it ohm out etc.
theogre APR 19, 06:23 PM
If has HEI or anything like it, unplug the tach filter is #1.

see https://web.archive.org/web...t/~fierocave/hei.htm
jelly2m8 APR 19, 06:41 PM
Was only the 93 LT1 that had a tach filter, fair chance there isn't one. Even GM made away with it.