Hi friends, I have a 99’ ls1. I am having terrible issues all of a sudden. I purchased this car back in 2010. It’s been running great all these years and I kept up with fluids and maintenance. It is garage kept. Everything was running perfectly after I changed my clutch and was breaking it in taking it easy.

Here are a few issues, do you think they all could be caused by a bad pcm?

When ever I try to start the vette it takes at least 3 turns of the key to get it to start up. I I can hear it trying to start but it doesn’t until about the third turn and then it starts. Occasionally the first turn will do it but less than 25% of the time.

I turn the key off and take it out of the ignition and the engine keeps running then stales.

All the lights except for the head lights flash like the hazards are on. (Turn signals, fog lights, break lights.) All of the exterior lighting blinks at the same pace. I put the headlights on same deal, I put high beams on they stop blinking.

When I accelerate it stumbles at about 2,500 rpm’s. It’s acts like it’s bucking. To me it seems like it’s not taking the gas.

I ordered a fob and programmed it but it doesn’t unlock the doors until I’m at the door and I have to smash the button like 50 times. I could just use the key at this point. I also replaced the battery. It was used of course maybe, I got a bad one but they are expensive for a 99’ and getting harder to find.

Any advice would be helpful and if you have any questions please don’t hesitate to ask. I will try my best to answer. Everything was great then it all went haywire on me at once.

 

If you don't have any electrical experience, a factory level scan tool and maybe even an oscilloscope you will just be guessing and replacing a bunch of parts...too many things going on here to diagnose it for you over the internet...seek out a professional !!

 

Thanks for your response,

It first started with the starting issue happening and I brought it to my mechanic and they changed the cam shaft position sensor and crank shaft position sensor. It still wouldn’t start on the first turn. Then it started not turning off intermittently. The next week or so it started the bucking issue. I parked it for about a week then the light issue started happening.

I am having trouble finding a tech that actually knows a 99’ vette. They all say they don’t know the car and the dealership is the same way. I really don’t know where to take it. I live in MA does anyone have a recommendation? It’s sitting now on a tender, sad sight to see.

 

Mechanics or "Techs" only change parts and it looks like yours guessed and replaced a few sensors already !!...a tech that knows a 99 Vette isn't going to know any more than your mechanic...you need to find a diagnostician as they test and only replace one part...they can diagnose any car and any problem.