Here's the issue. 93 won't start, just cranks and cranks.

This all started a few months ago. First symptom went like this:

Driving down the road the car just all of a sudden acted like someone gave a distributor a half turn. Lots of popping and studdering and such, I could even smell gas sometimes.Sometimes it would do this for just a couple of seconds, sometimes a bit longer. Then, as quickly as it happened, it would go away and the car would drive just fine.

This would progressily get worse. It would get to the point that I would have to pull off the side of the road while sputtering along and attemp to restart after it would finally die.

Eventually it just died on the side of the road.

The car sat till now. I had to take the battery to a local auto part store to recharge the battery, it was dead from both attempting to start the car and sitting for so long. They told me the battery was bad and replaced it (for free due to warranty). I do not believe this to be the issue.

I tried to restart the car with the fresh battery with the same issues...it just cranks and cranks with no attemp tp fire. I do not smell gas at this time (there is gas in the car BTW).

I attempted to pull the codes at this point. Using the paperclip method all I could get was code 12, nothing more. I'm guessing my codes reset due to the dead/removal of battery?

My question is, where to start now.

I do have the MSD 6al but I tried to bypass it before with no change.

Any suggestions???

All comments are appreciated.

Eric

 

Did you check for fuel pressure at the rail yet.

 

No I didn't. What do I need to do this and what are the steps if you would?

Would a failing fuel pump cause these symtoms?

Also, I forgot to add. I replaced the Opti about 20K miles ago and the motor hasn't been wet. I thought I better add that.

 

Well, theres people here that know way more than me but since no one else is responding i'll take a shot at it, on the fuel rail on the passenger side of the engine toward the cowl, there's a schrader valve,(it has a cap on it) where you can hook up a fuel pressure gauge to gheck the pressure when you turn the ignition on. not sure what it should be, but you can do a search to find out. you can also depress the center of the valve and find out if it's building up pressure but be careful as fuel should shoot-out, have lots of rags handy to catch the fuel. If thats not the problem, than it could be ignition related. Hope you get this thing figured out

 

Very good, thank you. I guess this is as good as any place to start huh?

 

I'd agree to check the fuel pressure first.

If the fuel pressure checks out okay, use a noid light to check for pulses at the injectors.

If all checks out so far, it's almost surely an ignition problem, and the misfiring you described is very typical of a carbon-tracked cap on the Optispark. Check for spark quality at the coil, and at the plugs, and report back to us after you've done all of this.

Be well,

SJW

 

assuming you have spark, fuel and pressure, i would surmise that maybe you jumped time.........

 

Impossible to jump timing with an Opti.SJW is correct.If you don't have it get the FSM from www.helminc.com for your car.My guess is either opti, Ignition control module or fuel pump and all tests for them are in the manual.

 

rather unfamiliar with opti but, based on your post, are you implying that there is no timing chain that could have slipped? i have a fsm (helms)....

 

Unless you've got extremely high mileage, I doubt the timing chain has jumped. Sad fact of life, but frequent opti changes are commonly needed with these cars.

 

I think what RedEasy was suggesting is that the Opti is pretty nearly immune to distributor-related timing jumps. The drive mechanism for the Opti could conceivably fail, but I've never heard of that happening and in any case, it would require removal of the Opti to correct it.

Yes, the LT1/LT4 engines have a timing chain, and yes it can jump teeth. I've never heard of one doing it, but it's possible. In this case, I believe that's not what happened, because the fault described by the OP was intermittent in the early going, and has now progressed to the point where he has a no-start/no-run condition -- not a likely progression for a timing chain.

Note to the OP: If the car cranks normally (not fast as though the spark plugs have been removed), you don't need to worry about your timing chain. If the chain had broken/slipped, you'd have compression losses that would lead to a fast-crank condition.

Be well,

SJW

 

I will pick up a FP gauge in my way home tonight and check it. I may need a walk through on checking for pulse at the injectors. What is a noid light?

Thanks!

 

How do you test the Ignition control module?

Thanks!

 

Autozone can check it but make sure they allow it to warm up first.To fully trouble shoot the system you will need to follow the steps in the FSM.It will rule out wiring issues also besides the module.My recent ICM failure sounded a lot like what your experiencing but it could be the opti too

 

Are you suggesting that I push it all the way to Autozone? Are you going to help?

 

Duh take it off and take the module to the store. Warming it up entails leaving the voltage on it for a while.They get hot and are prone to failure if the proper heat sink paste is not applied to the back of them when installed.

 

I should have read into that further. Thanks for the clarification.

I guess I need to remove the module and will they know the steps needed to test it? Sorry if these questions seem a bit simple, but ignition systems on Vettes are a bit new to me.

I do have a manual, go it from a dealer back home (relative is the parts manager). I hate using it due to it being a poor read, is there a better (easier to understand) version out there?

 

Almost the same thing has just happend to me. Pleanty of fuel and air but no spark. Shop is still working on it but they did finally started it! They replaced the entire distributer back to stock. I did not want that but if thats what makes it work then fine. Good luck

 

Before you go nuts, check your coil wire and make sure it isn't rubbing against your water pump. This happened to me and I had the same symptoms as you describe.

 

Great idea. What's the best way to view it? From the top or underneath? And did you or would this cause a no start?