My '96 Z28 is kinda giving me fits. It has intermittent electric issues, like cranking but not starting, and it quit once while I was driving. I have been paying attention to the security light at start up, it seems to be ok.
My question is this : If I invest in a digital multimeter and start measuring voltage and resistance per the Haynes manual and Shoebox's excellent web site, will an intermittant problem show up ? I have the car at home, and start it on a regular basis. Starts up every time, but I have not been driving it 'cause I don't want it to stop running and leave me stuck. 2-3 times it has left me stuck and restarts after sitting about an hour or so. Thanks for your help, I need all I can get.

 

have you checked the fuel pressure?

 

I would first replace the gas filter.,Has the car ever ran out of gas?If so,the fuel pump could have over heated,and is toast.It's inside the gas tank.Might check to make sure all the electical connections are clean and tight.ie,battery terminals ,ect.(good battery).Hope this helps.

 

No idea why people are suggesting fuel issues.

An intermittent starting problem with shut off when hot, only to restart later sounds to me to be the ignition control module. These are known to have heat soak problems. The best way to check it is to remove it and take it to AutoZone. Test it both cold and after hearing it up with a hair dryer. I think you'll find it there.

Usually intermittent failures causes by a break in the wiring is difficult to find. You can have good continuity or voltage at any time. I like to connect the leads and them move the harness or connector around....sometimes that'll do it....

Anyway, good luck. Chasing down those bugs is a pain...

 

Thanks for the replies. It has not run out of fuel since I've owned the car, about 5 years now. Due to the randomness and seeming pass/fail of the problem I am experencing I was thinking electrical problem. I did call O'Rielly and Pep Boys, they were only able to check altenators and starters. I need to call Auto Zone. Tonight I started my Z and let it idle for about 5 minutes or so, then turned it off. Waited another minute and it started right up. Why not ? If it fails now it is already home, can't leave me stuck somewhere.

 

Keep in mind that there are problems that set codes but do NOT set an SES. Like a DTC 16. This is the low res feedback signal from the opti. Engine will crank, not start and there will be NO SES.

Many many folks have experienced corrosion on the connector at the opti and have experienced intermittent problems. This is not the only intermittent problem you could have. With a 15 YO vehicle, any thing could be wrong especially with wiring and connections.

Mine, would not start on very humid mornings. Later that day, no problem. I knew it was from condensation in the opti.

My first suggestion is to scan it for history codes. Then take apart the connections to the ignition items and check for bad pins, or corrosion. Before putting them back together, put dielectric grease on the connector.

Intermittent problems are the worst. I feel your pain.

 

Update. Today, 4/2 I finally went to an Auto Zone that was able to test the ignition control module. It passed 7 tests in a row. I have to admit from what I've read I was hoping for the module to test bad.
Auto Zone is unable to test the ignition coil, is there a way to bench test it that I can do ? My Z28 received a Jasper LT 1 about 4 years ago, and at that time a new Delco optispark was put in.
With time to think about the problem, I had a little warning something maybe up. It would crank over but not start ( at times ) almost a month before it stopped running while I was driving.
The check engine light is out for now also. The problem as I define it now is it always cranks over good, but it stopped running while driving once. Before that it would crank but not alway start up. And now a few times it needs to sit for up to an hour before starting when the car is driven. The car has been in my back yard for the last month and has started EVERY Single Time I have tried, including letting it idle for 10 minutes, shutting it off, and restart.
I picked up some spray electronic cleaner and dyaletic grease and will clean connections also.

 

As Speedy already said, there are "fatal" codes that don't turn on the SES light, but the codes will be stored, even if its an intermittent problem shutting things down.

 

Seen the fuel filter get clogged and cause sputter, to only work again hours later... Same with fuel filter. I had a Jeep that kept dropping the ground to the pump randomly due to bad capacitors in the pcm. There are plenty of reasons fuel could be a symptom causer here.

 

So I should go to Auto Zone and see if there are any codes stored. Ok, thats something I can do. Sounds like I'll put the coil and module back on the car, cleaning the electrical connectors and take a ride.