The regulator can be heat-affected, considering it'* proximity to the firewall and rear manifold. I dunno. This is a new one on me. Have you check the pressure at the rail?

Thihg is there is not a single code in the system. This is why Im thinking now pressure regulator. Im going to tape mine gauge up and tape it to the hood and see if pressure is low when it does decide to go flat again. Im hopeing this is it.

If MAF or TPS went off if only for a moment it would / should throw code ? Right ?

Well heres the updated grand finale to the aging saga

After nearly 11 full months of ownership I was awarded complete refund, including tax, licience and title bla bla.

In late Aug after the new pressure regulator also did not fix the problem the dealership told me they would no longer spend any time on the car so I began a lemon law persuit with NYstate attorney Generals office. I had four shops drive the car and witness the phenomona and document it. I made a multitude of copies of all service invoices as well as the evaluations from the four shops. From there is just built my own case, no lawyer and it went to Lemon Law arbitration in Feburary. I was awarded the victory within a month. Two weeks ago I had the remainder of the loan paid off and recieved a check for the equity I had invested which was a nice amount and I was glad to deposit it straight into my savings account.

So I drove the car for roughly 5 months and 10,000 miles. I got all my money back so it was free except the hastle which was not worth it. I still didnt feel well about the car and was sad to think of its fate with a branded title. The damn shop just should have admitted to the problem and figured it out instead of trying to get me to live with it. Even worse they wasted a fair amount of money repairing stuff that was not the problem.

But really, how could I live with driving a car that was mint, I really like the looks of, like driveing and has the power train that I have swore by for years but yet runs like crap everytime you turn around and no one can figure it out.

Its over.

Glad to hear things are mostly taken care of.
So what'* the plan now? L67 Riviera? Or did you already get yourself a new ride?

I bought the 90 Regency back in the fall and have been happily driving that since. Its got 317,000 miles on it and runs great. I just took care of the few areas on the car that had begun to rust, put F41 suspension, ground out the rear exhaust manifold, new rear brake hoses and its good to go.

Jr. - No they never tried anything with the PCM. Their offer was - I could take it out for a drive with a regional manager and if he felt is was running improperly they would try to further fix it. I had been through this with them before and knew I could not get them to recogonize the problem. I would have only wasted my time driving around in the car only to have them tell me "no two cars run the same". The route I went was the best, otherwise I would have just been further jerked around. All the other mechanics that drove it said they would want their money back too but not this dealerships people, they said there was no problem. One guy that took it out was a friend that is the service manager for another dealership, a Pontiac dealership. The engine did not act up while he was out but the tranny was squalking terribly, he repeatedly made it shudder from stop with about only half throttle, he even said he would want his money back and that he could not believe the tranny was just rebuilt. Then the tranny didnt even do that all the time. Clearly something in the car was being tempermental and would affect line pressure in the tranny and fuel pressure/fuel ratio or timeing in the engine. Never both at the same time, obviously. When the engine was strong it would make the tranny shudder, when it was falling on its face it certainly would not shudder the tranny.

It was a really freaky car. It was kinda like one of those real beautiful girls that turns into a complete sycopath out of the clear blue.

I didn't understand any of this before, but I now know I can relate.