I have a 1998 WS6 with 243 heads ported and polished. and performance cam.

The car randomly fails to start. It cranks fine, but refuses to start at times. When it fails to start, it sometimes starts a day or two later.

I've had the key switch/replaced and new keys made after receiving suggestions that the problem could be a faulty key switch failing to communicate with the ANTI-theft system.

A Chev dealership service department cannot find a cause. The service department told me that the anti-theft system was designed not to be disconnected without possible injury to the ECM computer. Therefore, they will not disconnect the Anti-theft sys for me. They don't know how to disconnect the alarm.

They are afraid to replace the computer with a new one because the current computer has been reprogrammed by the dyno tune. The replacement computer might not read the ptogram for the new cam, jets, and heads.

Does anyone have any experience or knowledge or suggestions?

Fellows, I NEED HELP! PLEASE!

 

Why not just bypass the anti-theft system, lots of guys here have done this as i have, and i haven't had a problem ever since then with my anti-theft system.

 

Is there any DTC's in the PCM or BCM? If it is a VATS issue there "should" be some DTC history.

You need to check fuel pressure, spark and injector pulse when it's not starting.

It could be VATS related, crank sensor, ground issue or a bad commentator(s)in the fuel pump.

 

Moving this to a more appropriate section. Not really a question pertaining to engine internals.

 

Update on the random faailure start syndrome...
I took the car to GANLEY CHEVROLET on Brookpark road, Cleveland, Ohio to get the ignition switch and new key assembly replaced. My car was kept in their shop for 4 weeks. I was charged $1404.00 for the many diagnostic test at $100-dollars per diagnostic test. After 4 weeks I called the Ganley Chevrolet Dealership Service Department and asked them to install the new ignition assemply. The car started on first attempt when I drove it home from the Ganley Chevrolet Dealership located on Brookpark Road in Cleveland Ohio.

I've started the car every day for the last 3 weeks without a starting problem.

I am now reasonably confident that my starting problem was resolved by the ignition switch replacement. But I feel that $1404 for diagnostics was a shakedown.....What is your opinions about the shakedown?

 

Did you pre approve that much diagnostic work?

The shop I work at, and most shops are the same way are; When you drop your car off it's an hour minimum for diag. If that hour isn't enough we call the customer and request additional time and explain why.

Unless you said, "whatever it takes, call me when it's done" you should not have that big of bill without your prior approval.

 

To be exact, the diagnostic was quoted for $115. When I picked up the car and only when I picked up my car, I was told that the charge was $115 plus labor for EACH diagnostic.
there are many different types of diagnostics.......
1)diagnose fuel pressure and pump
2) diagnose cam sensor
3) diagnose ignition hey chip
4) diagnose injector sensor
5) etc., etc., etc

Does the shop that you work at do Pontiacs? Is your shop close to Cleveland Ohio?

Thanks for replying

 

If that's what happened I would have contested the charges but if you have already paid I doubt there is anything they will do.

Yes my shop does work on Pontiacs but we are in southern Indiana.