New paint was applied 3 months ago started to get small blisters just like the orignal. What cause this .

scrape prep and repaint

PPG basecoat is probably part of a water based wet-on-wet painting system designed so each successive coat can be applied in relatively quick succession and then baked in an oven, followed by the activated lacquer so the whole job can be completed in less than a day.

I had cause to do a minor body repair to a vehicle that had been refinished some months before with the PPG water based paint system - I was surprised to find the base and primer coats were still moist and tacky and the new paint reluctant to adhere to the feathered edge of the PPG paint.

In conclusion I would guess you can apply epoxy primer as in reality it is little different from the epoxy lacquer in the above example...

Just a guess, but it is likely that moisture is causing the paint to peel. I suggest you remove as much peeling as you can with a wire brush and then use a waterproof sealant. I had very good luck with a product they sell to seal cement walls in basements with moisture problems.

automotive paints require a good clean and well prepared surface like light waterpaper sanding to remove any oily or fatty resedu and the correct undercoat before applying a new coatings otherwise it will not last chipping or peeling will occur.

Have the fuel; pump checked for pressure bleed down after sitting, it should hold pressure within 5 PSI of rated running pressure after shutting sown the engine for extended periods.

Have you checked the catalytic converter? After 20 years they do pug up causing some of the problems you describe

the same is happening to the out side but they dont recall it if they dont have to! lose too much money!

You have have the orignal master key the car came with or have a new key programmed by your dealer.(some small shops have tools for this too).The key has a chip in it that the computer looks at (a code) that lets it start if it's right.if it gets damaged,or a non-chip key is inserted,the vehicle won't start and the anti theft light blinks.

No, that would probably be the clearcoat and would need refinishing.

First Wash the area, than take a dremel and with the wire wheel @ high speed, grind off the bistering and feather as best into good paint. Next rough up the area with some 100 grit sand paper. Use body filler (bondo 2 part filler) and smooth over with plastic blade. When dried work with 220 grit sand paper till you achieve the lines you want. spray cover with primer and apply touch up paint(Dealer has the best matchs) in coats. When happy with color use a 400 grit wet sandpaper to get a highly smooth finish and when dried cover with a clear coat finish.(Auto part stores). Buff when that dries and I guarantee thats the cheapest easiest d-i-y- fix you can get.