Does anybody happen to know the correct upgrade EPROM number for a '90 240 non turbo , no EGR. ECU#: 0 280 000 561.?

I recently purchased an EPROM Volvo part # 271836 From Trollhattan, the part number was given to me by my local dealer (who I don't trust), but verified by Trollhattan's supplier.

After installation all it would do is make the fuel pump relay click like crazy , but not start. ( no ,I didn't zap it I have a very nice anti-static work station)

I put the old one back in and it runs fine.

I called Trollhattan , they called Volvo who said it was the right # but a bad chip and they replaced it.

The new one came in today and I installed it and the very same thing happened.

I am beginning to suspect an incorrect part number as it is pretty rare ( although not unheard of) to have two bad chips behave exactly the same.

The old good EPROM was marked as follows:

Top- (on sticker)2287356722

B 57 605

9202BLZ

Bottom- Malaysia

8916JP R 9756

The new bad one is marked : Top- (on sticker) 2 287 357 883

B 57 995

LDP9306

Bottom- L27C256D/312223

Singapore 06

The ECU is # 0 280 000 561

078

3517407

In case you're wondering, I'm replacing the old one because I just finished replacing everything connected to the ECU and some of the items had some rather high resistance values so I'm replacing the weak link in the ECU (and besides , I'm too big a tight-wad to fork out for a new ECU)

Thanks-----------Robert