Im scratching my head. I have a 100% original 1988 IROC 5.7 litre. Ive had issues with the car occasionally not getting spark but only when trying to start the car (it never happens once the car is running). There are times when I can go out to the garage and she wont fire--just turns over. Ill walk away and the next day go out and it will fire right up.

So, I know its not a lose wire and Ive replaced the coil 3 times (thinking that was the problem). At this point Im wondering if it could be a relay issue? What else would work one day but not the next without the car moving? Its definitely spark and not fuel (verified with a test light).

Ideas??

 

My guess..........Bad ignition module.
Its usuallly inside the dist. depending on year model.
When it is going bad it causes a random no spark at any time condition.

 

But the ignition module is inside the distributor--how can that effect the spark coming from the coil? Is my thinking backwards?

 

For a good while there, my car would die on me completely at random.. I'm talking in my driveway, in the drive through, downtown, in the middle of packed traffic (Yeah, that wasn't embarrasing...)

Anyways, I ended up getting tired of it, and replaced my ignition module after researching on TGO a little bit.

No more randomly dying vehicle

 

Did you still have spark though (at the coil) when your ignition module was acting up on you?
My issue is spark is lost at the coil randomly.

 

yeah, but the ignition module controls the coil, if it is intermittent then the coil would not fire at times due to the bad ignition module. Sounds like a good idea to check that out. Also a weak battery or battery that has low cold cranking amps would also not leave enough power left over from starter to spark ignition, or even a weak starter drawing too many amps. might wanna have those checked as well but I would go with igntion module first.

 

Interesting....I didnt know the ignition module controlled the coil. Ok, I will replace that and see if my problem goes away.
The battery is strong and the starter is brand new.
Would you trust parts from Schucks or Napa?

 

Most if not all of them are made in china/mexico or some third world country anyhoo and the last one I installed in my buds winter rat (that also had random no start/no spark issues) was a $15 cheapie he got at PeP boys.
Not a problem almost a year later !

Your lucky you don't have a later model 350 with that Opti-spark setup (controls spark/ignition and located behind the water pump)! Those could be a troublesome SOB at times with the early models !!!!!!!
Did I mention $pendy to fix??????????

 

Here's another "interesting," the ignition module is triggered by a pulse from the pickup coil inside the distributor. under plate where you can see it.
The pickup coil can also cause no, and or intermittent spark.
The ECM also use that trigger to pulse the fuel injectors, and to make matters worse the VATS system can also disable the injectors via the ECM.

 

Buy Borg Warner or Accel, I have never had trouble with those two brands when it comes to ignition modules...

 

What year was VATS used in the Cam/birds?
IIRC my 87 T/A didn't have it................

 

So when you are cranking you loose spark but if you let go of the key and let it stay in RUN you have no issues?

Can you stick a test light on the voltage going IN to the dist and watch it when cranking?

Keyswitch maybe?

 

When was the last time you changed the spark plug wires? They can cause problems. It happened to me.

 

My car only has 110,000 miles and the plug wires look brand new.

I replaced the ignition module and rotor on Saturday morning and drove it all day on Saturday (60+ degree day--yes, the T-tops were off!!), had tons of start ups and it started everytime so hopefully the ignition module was the culprit.

 

True, your car only has 110k and your wires "look new".

Also true, your car is 22 years old.

 

So it WAS the ignition module huh????????

Thought so..........common issue and cheap to fix !

Happy crusin!

 

My Bird has less miles than that, I think .. .and I have replaced the wires since I've had it (1998) about 5 times already... I haven't replaced them in the last 5 years, since it has been garaged... but car still fires up nicely with just the tap of the key...

 

Update: Still NO issues! Fires up everytime without fail! Thanks guys for suggesting I replace the ignition module! I would have never thought that one less than a year old would be the problem (especially when it was so intermitent).

 

Update: This problem continues occasionally. It happened again last summer and I had to be towed. I replaced the ignition module (again) and she started right up. I then had a battery giving me problems and after replacing the battery didnt have any more problems with the car starting...

I park the car during the winter so it hasnt been on the road since early November.

Last week I started her up and took went for a drive. Parked the car at a store after driving 10 miles and when I went to start the car it just turned over and wouldnt start. I ended up having to be towed home!!

The tow truck left the car in my driveway. A couple hours later I got into the car and she fired right up! What gives?? How can I have no spark and 2 hours later have spark without doing anything?

Could this be an ECM issue? My new battery is also being drained to zero volts if the car sits a few days. I have it permanently hooked up to a trickle charger now.

I would appreciate any suggestions anyone has.

 

Interesting comments. I have a similar problem (maybe). I have an 88 TBI 305 5 spd car which I have just installed an L98 cam. The car will initially fire once or twice and then it just turns over. I am getting fuel and I set the timing to 6 degrees BTDC. The distributor is installed correctly. My timing light shows sparks on both the #1 and #6 spark plugs. Is there a chance that the distributor module is putting out a weak spark (enough to trigger my timing light) that will not be strong enough to give a good spark to the sparkplugs? I am running out of things to try. Thanks.